Stella 2T highway/performance upgrades
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Addicted
1980 P200E project, 2005 Stella Malossi 166 MKIII
Joined: 20 Jul 2018
Posts: 537
Location: Staten Island, NY
Wed May 29, 2019 4:20 am quote
Jack221 wrote:
If you leave the pin in the freezer it will go in easier.
good tip! I will try that!
Jack221 wrote:
If you drop the back of the engine down the cylinder slides off with the studs on.
I tried that and the lml cylinder fins were still hitting the frame.. so I had to remove studs to get the cylinder off. and even with the studs off.. i still had to rotate the cylinder so exhaust port was facing out with piston fully bottomed out for it to come off. I wouldn't have been able to rotate the cylinder fins away from hitting the frame with studs in.

I did take note of which end of studs goes down.. the wider thread pattern as on these lml studs the top is a short thread pattern, bottom longer thread pattern.
Addicted
1980 P200E project, 2005 Stella Malossi 166 MKIII
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Wed May 29, 2019 4:24 am quote
charlieman22 wrote:
Jack/Swiss - good stuff.
Headed down similar path for plug and play.
Tips and Swiss's postings on challenges super helpful.
Question: in the world of auto's, I was always taught that head studs had to be replaced - same with rod end studs - due to stretching.
Sounds like that is not strictly tru for vespa's?
What cylinder are you putting onto your side car scoot?
Addicted
1980 P200E project, 2005 Stella Malossi 166 MKIII
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Posts: 537
Location: Staten Island, NY
Wed May 29, 2019 10:33 am quote
Measured port timings using freak mopeds process..
Measured the exhaust, transfer (first to open), head and included gaskets using freak mopeds technique. Decided to notate these measurements using his same style including the comma instead of period like we do in 'merica.

The base gasket not sure exact measurements because it's embossed. Was .5mm across the whole gasket including emboss... Was around .29-.3mm if i measured a pinch just on the edge before the embossing starts.

I'll put the cylinder on and measure pbt with no base and then put the included base gasket on and measure pbt again. Then I'll be able to plug those numbers into the port timing calculator fmp uses to get these pnp numbers.

Kit included 52/140 idle, be4 and 105 and 115 main to use on stock carb. 105 main for stock ignition timing, 115 for advanced timing.. Although the instructions say to use 18 deg before tdc.

Assuming the piston would be flush with top of cylinder without base gasket (have not installed yet to measure pbt), then these current measurements with included gaskets installed would have the port timings set to:

exhaust: 176 deg
transfer: 123 deg
blowdown: 27 deg
squish (guessing based on gaskets and head measurements): 1.75mm

Which is pretty close to desired timings as is. I am trying to understand the port timings and reasoning for setting them at different points. From what I understand is that this transfer time of 123 deg is higher than my desired 120 deg.. so it means the engine will be peakier/revvier and less torquey. So if I eventually raise the cylinder up and grind out the exhaust port to correct size to bring blowdown back into range then that will lower the rpms and bring back some torque?

IMG_20190529_093603_01.jpg

IMG_20190529_093556_01.jpg

IMG_20190529_093045_01.jpg
I use NGK plugs so the equivalent to this Denso plug is a BR8ES. I am at BR6ES on the stock setup as suggested by Jack and the manual.

Hooked
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Wed May 29, 2019 11:30 am quote
following because the timing stuff is a mystery to me. Tried using the calculator but I'm not entering the data correctly.
Addicted
1980 P200E project, 2005 Stella Malossi 166 MKIII
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Wed May 29, 2019 1:20 pm quote
Question.. cylinder studs. Screw them down to bottom out and won't go anymore or until certain torque, or just until the full thread pattern is into case? Not the head nuts but the studs themselves. But now I'm confused as i went to the thread about cylinder stud install from a month or two ago and someone said the short threaded end goes into case, but I'm pretty positive when i removed these studs the longer threaded end went into case.. which way into case?

Btw, proven as soon as cylinder on.. works out of the box with auto start flywheel.. No grinding.

IMG_20190529_172430.jpg

Addicted
1980 P200E project, 2005 Stella Malossi 166 MKIII
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Wed May 29, 2019 3:58 pm quote
OK so I temporarily put the studs in far enough to torque down the cylinder with some spacers so I could measure PBT without base gasket. Also re-measured the gaskets and the head taking the avg of multiple measurements around each.
hibbert wrote:
following because the timing stuff is a mystery to me. Tried using the calculator but I'm not entering the data correctly.
I am still trying to figure out exactly how to measure and what measurements plus or minus pbt go into the calculator, but I am using FMP's guides for measuring and adjusting port timing here:

https://www.youtube.com/watch?v=MvGNkw1g6C8
https://www.youtube.com/watch?v=slA7204S6v8
https://www.youtube.com/watch?v=CPDCTUE_eKs

Here is what I gathered from watching these videos from my own measurements

PBT = -0.71mm
Head = 1.14mm
base gasket = 0.25mm
head gasket = 0.5mm

Squish (no gaskets) = PBT (0.71mm) + Head (1.14mm) == 1.85mm
Squish (base gasket only) = PBT (0.71mm) + Head (1.14mm) + Base (0.25mm) == 2.1mm
Squish (both gaskets) = PBT (0.71mm) + Head (1.14mm) + Base (0.25mm) + head gasket (0.5mm) == 2.6mm

I am also confused on exactly what to calculate when making changes to base gasket vs head gasket from these videos as sometimes he just uses PBT, sometimes he uses the total squish.. he subtracts PBT/squish from the original measurements of exhaust and transfer ports and enters that into those fields on the calculator, but does not change the PBT field at all in the calculator.. which to me seems like if you add gaskets, PBT will change... so I started out thinking I understood it, but now that I am plugging numbers in and rewatching his videos, i'm more confused that I thought I was originally.

IMG_20190529_184307.jpg
1.14mm

IMG_20190529_184416.jpg
base = 0.25mm, head = 0.5mm

Addicted
1980 P200E project, 2005 Stella Malossi 166 MKIII
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Wed May 29, 2019 4:16 pm quote
Here is what I have come out with using the calculator for various methods.. not sure which is correct.

Exhaust port as measured not installed = 35.24mm
Transfer port as measured not installed = 46.97mm

Exhaust Port - PBT Only (35.24-0.71) = 34.53mm
Transfer Port - PBT Only (46.97-0.71) = 46.26mm

Exhaust Port - Squish no gaskets (35.24-1.85) = 33.39mm
Transfer Port - Squish no gaskets (46.97-1.85) = 45.12mm

Exhaust Port - Squish + Base gasket (35.24-1.85-0.25) = 33.14mm
Transfer Port - Squish + Base gasket (46.97-1.85-0.25) = 44.87mm

Following images are of each of these entered into calculator without PBT changing as FMP has done.

pnp no gaskets.jpg
pbt entered in piston stand, but not subtracted from the original measurements of exhaust or transfer

pnp no gaskets ports affected.jpg
same thing, this time I subtracted the pbt from the ports

pnp no gaskets squish instead of pbt.jpg
this time I used squish instead of PBT.. and subtracted squish from original port measurements... everything seems way higher than it should be in terms of timings.

Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1209
Location: London UK
Wed May 29, 2019 7:57 pm quote
swiss1939 wrote:
Here is what I have come out with using the calculator for various methods.. not sure which is correct.

Exhaust port as measured not installed = 35.24mm
Transfer port as measured not installed = 46.97mm
If these are the measurements of the exhaust port to the top of the cylinder and one main transfer (big one next to exhaust port) to the top, then these are the measurements you need.

With these numbers the timing comes out as a zippy but gutless 169Ex 113TF 28BD when the piston edge is at zero flush with the top. If its poking out 0.71mm with no base gaskets, then you'll need a few more base gaskets just to get to zero. 3 base gaskets should do it.

The 60mm crank will fix this nicely. If there is 1.14mm measured in the head, then you don't need the head gasket. Keep the head gasket for the 60mm crank as it will need it then.
Hooked
Joined: 26 Jan 2019
Posts: 364
Location: california
Wed May 29, 2019 8:30 pm quote
Quote:
What cylinder are you putting onto your side car scoot?
If its this tough to figure out - maybe none!

:-)

Kidding aside - boys have suggested a few prime options with the following being cream of the crop.
- Malossi 177 - modern high power/quality
- Pinasco 177 iron - rugged/reliable

Focus is on plug and play torque. Have a bit of research still going on that topic before final trigger pull.

Your experimentation and path beating on cyl replacement couldn't be more well timed for helping with overview & details. Same mindset on picking up some reliable power - ina certain range - without case split.

Appreciate all the pics and details as you sort it out. Super helpful.
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1980 P200E project, 2005 Stella Malossi 166 MKIII
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Wed May 29, 2019 10:51 pm quote
Jack221 wrote:
swiss1939 wrote:
Here is what I have come out with using the calculator for various methods.. not sure which is correct.

Exhaust port as measured not installed = 35.24mm
Transfer port as measured not installed = 46.97mm
If these are the measurements of the exhaust port to the top of the cylinder and one main transfer (big one next to exhaust port) to the top, then these are the measurements you need.

With these numbers the timing comes out as a zippy but gutless 169Ex 113TF 28BD when the piston edge is at zero flush with the top. If its poking out 0.71mm with no base gaskets, then you'll need a few more base gaskets just to get to zero. 3 base gaskets should do it.

The 60mm crank will fix this nicely. If there is 1.14mm measured in the head, then you don't need the head gasket. Keep the head gasket for the 60mm crank as it will need it then.
That 0.71mm is not sticking out.. It is sunk in 0.71 mm on the edge. I guess the crown at the center is sticking out with the edge -0.71mm from the top edge of the cylinder with no base gasket.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
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Location: London UK
Thu May 30, 2019 1:11 am quote
Well that's better and worse

The port timing as bolt on does get better 172EX 118TF 27BD which is ok, not great but ok. Will go fine.

The squish however, is buggered. 1.0mm + 1.14mm = way too much. No ones intention to have a squish that big. Measured with solder will be actually bigger. It will run and be ok but will lack something and especially at higher rpm. I would suggest putting the LML150 head on as that looks better but with that big LML locating pin it won't fit. It's only for the summer. The Malossi one will do.

With the 60mm crank it will all be fine. Everything works out good.

So for now. The one aluminum base gasket and no head gasket is the best it will get on the 57 crank.

Be sure to use the AC140 BE4 115MJ and the 52/140 jetting for the first start up. You wouldn't want to seize it before its out the garage.
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Thu May 30, 2019 4:05 am quote
Jack221 wrote:
Well that's better and worse

The port timing as bolt on does get better 172EX 118TF 27BD which is ok, not great but ok. Will go fine.

The squish however, is buggered. 1.0mm + 1.14mm = way too much. No ones intention to have a squish that big. Measured with solder will be actually bigger. It will run and be ok but will lack something and especially at higher rpm. I would suggest putting the LML150 head on as that looks better but with that big LML locating pin it won't fit. It's only for the summer. The Malossi one will do.

With the 60mm crank it will all be fine. Everything works out good.

So for now. The one aluminum base gasket and no head gasket is the best it will get on the 57 crank.

Be sure to use the AC140 BE4 115MJ and the 52/140 jetting for the first start up. You wouldn't want to seize it before its out the garage.
Ha ok. I'll do that for now. Btw any suggestion on stud installation? I'm pretty positive longer thread down but how far or tight do you install them?
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
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Location: London UK
Thu May 30, 2019 4:30 am quote
The stud thing is risky. The same end should go back in the case. The head end stretches more. If you put an old head end in the base end it could strip the casing thread.
Usually the short thread goes in the base but who knows with LML.

Run a new nut down the thread before putting one in the casing. If there is an issue only the nut will be damaged.

Last edited by Jack221 on Thu May 30, 2019 4:52 am; edited 1 time in total
Veni, Vidi, Posti
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Thu May 30, 2019 4:48 am quote
Re: pulled the stock cylinder off finally
swiss1939 wrote:
Got so frustrated with the stupid stella automatic not starting and stumping everything I tried today.. so I gave up on that and switched over to the 2 stroke stella. Pulled the stock cylinder off (after removing the studs.. what a pain to do while still in frame)...
Next time you have the motor out, reinstall the big pivot bolt backwards, head on the far side away from the motor, nut and washer on the near side. That way the next time you need to remove the cylinder or studs, you can remove that nut, pull back the pivot bolt a little then swing the 'corner' of the motor down nicely for easy access without undoing anything else.


I think your seal is fine or you'd have oil on your brake shoes & vicinity. It looks that way because the seal seals on the hub you removed, not on the axle and a bit of oil drooled out with no more seal to keep it in.

To learn more about these magical CR80 corks, look here for some interesting discussion: Honda CR80 clutch disk page, what have you got?
They're cheap, even at your local Honda shop, and you can do it yourself for a big improvement on any 7 spring until you go big power & you get the Cosa clutch.

Great thread, I too am learning much.
Addicted
1980 P200E project, 2005 Stella Malossi 166 MKIII
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Thu May 30, 2019 4:54 am quote
Jack221 wrote:
The stud thing is risky. The same end should go back in the case. The head end stretches more. If you put an old head end in the base end it could strip the casing thread.
Usually the short thread goes in the base but who knows with LML.

Run a new nut down the thread before putting one in the casing. If there is an issue only the nut will be damaged.

You have 3 base gaskets?
Only one base came with it. I've bought a bunch various sized spares:
0.5
0.8
1.0
1.5
2.0
Molto Verboso
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Thu May 30, 2019 4:58 am quote
Enough gaskets for the 60mm already.

For now it's either the thinnest one you have or just gasket sealer and no gasket.
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Thu May 30, 2019 5:31 am quote
Jack221 wrote:
Enough gaskets for the 60mm already.

For now it's either the thinnest one you have or just gasket sealer and no gasket.
You've scared me enough to order new studs and wait till they arrive to install new. I've double checked the service manual and they never mention removal or install of studs. Whichever way they go in, do you bottom them out then torque or do you just go till full thread pattern is into case and stop?

Given thin or no gasket, which would you do and be better performance pnp?
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Thu May 30, 2019 6:06 am quote
I've also remeasured exhaust and transfer ports as carefully at possible after removing head again.

Here is the average of 3 careful measurements of each from top of cylinder to top of port

Exhaust 36.28mm
Transfer 47.41

I forgot to measure the pbt again before removing head so that previous measurement stands for now at -0.71mm

Last edited by swiss1939 on Thu May 30, 2019 9:21 am; edited 1 time in total
Molto Verboso
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Thu May 30, 2019 6:06 am quote
I tend to screw them in all the way, apart from the one that I reference below. You may find that the studs have longer threads at one end. I usually put that end into the case. You just need to make sure that you have the right amount of stud poking through the head, so that you can get the two washers and head nuts on fully. If you have autolube, be careful not to go in too far with the top stud nearest the frame. It can jam the autolube cog behind the clutch. That stud also needs to be slightly further out to allow room for the cowl extension nut and bolt.
Veni, Vidi, Posti
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Thu May 30, 2019 6:08 am quote
Your last questions reminded me that I'd recently seen some good info on this topic and I finally found it here: Question - Torque and technique for installing head studs. Turns out that one of the parts I liked best was posted by you : http://modernvespa.com/forum/post2315040#2315040 . Ha, small world!

From that thread:
oopsclunkthud wrote:
installing the studs:
No torque here.
They have a short and long threaded end, the short end goes into the case.
make sure the threads are clean and use loctite (I use red for this)
I run them in till I can just see the top thread at the surface of the case, but check that they don't poke out the bottom of the holes and do nasty things like jam up the oil pump gear.

Torquing the head:
on 7mm studs (used on the VBC) 11ft-lb
work in a cross pattern like this:
1 3
4 2

and work up to the max torque, snug them first, then torque to 5 ft-lb, then 8, then 11
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Thu May 30, 2019 6:23 am quote
swa45 wrote:
You may find that the studs have longer threads at one end. I usually put that end into the case.
V oodoo wrote:
Your last questions reminded me that I'd recently seen some good info on this topic and I finally found it here: Question - Torque and technique for installing head studs. Turns out that one of the parts I liked best was posted by you : http://modernvespa.com/forum/post2315040#2315040 . Ha, small world!

From that thread:
oopsclunkthud wrote:
installing the studs:
No torque here.
They have a short and long threaded end, the short end goes into the case.
That is the specific thread i was referencing.. And herein lies the confusion. Two conflicting suggestions swa45 says long thread into case, oopsclunkthud says short thread into case. This makes me think it doesn't really matter as long as you don't bottom out the top frame side stud if long thread into case for reasons swa45 said. Given that...
swa45 wrote:
If you have autolube, be careful not to go in too far with the top stud nearest the frame. It can jam the autolube cog behind the clutch. That stud also needs to be slightly further out to allow room for the cowl extension nut and bolt.
How do you know what too far is? Any specific technique you use? Bottom out then back off a few turns?

I'm inclined to order new studs and install them short side into case until threads fully into case and call it a day since it won't encounter the auto lube interference swa45 mentioned.
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Thu May 30, 2019 6:40 am quote
Re: pulled the stock cylinder off finally
V oodoo wrote:
Next time you have the motor out, reinstall the big pivot bolt backwards, head on the far side away from the motor, nut and washer on the near side. That way the next time you need to remove the cylinder or studs, you can remove that nut, pull back the pivot bolt a little then swing the 'corner' of the motor down nicely for easy access without undoing anything else.
Good tip. This fall/winter when i tear the engine apart i will do that.

Last edited by swiss1939 on Thu May 30, 2019 6:41 am; edited 1 time in total
Ossessionato
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Thu May 30, 2019 6:40 am quote
1. Short end of studs go into the case.
2. Do not torque. Snug only.
3. They’ll stop when the last thread isn’t visible.
4. The only way they can be installed too far is if you put the wrong end in and really gorilla them down.
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Thu May 30, 2019 6:46 am quote
SoCalGuy wrote:
1. Short end of studs go into the case.
2. Do not torque. Snug only.
3. They’ll stop when the last thread isn’t visible.
4. The only way they can be installed too far is if you put the wrong end in and really gorilla them down.
Thanks for that.. these studs were definitely installed long thread in from factory. I am ordering new studs now and will install short thread down as suggested.

Now that that is resolved and I'll be waiting a few days for new studs, time to understand exactly what to make changes to with that timing calculator when i add sand remove gaskets. After a few months watching fmp guides i thought i was confident in how to do it, but now that I'm doing it with real world measurements I'm less confident!
Molto Verboso
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Thu May 30, 2019 6:52 am quote
Oopsclunkthud is probably the one to listen to for best practise, but I like to put the long end into the case, because it feels more secure to me. For the autolube stud, I'll either go short end first or use Loctite to stop it going any further. I just had to do this on one of my PX200 motors, as the genuine Piaggio studs that I bought had the same length threads on both ends ie. there was no short end like on a 125/150. When screwed all the way in, either end would have interfered with the autolube cog.
Hooked
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Thu May 30, 2019 7:22 am quote
Swiss - is the issue that you want to be careful to match what you had before disassembly - or that you are concerned it was backwards then - or both?

In any event - is there enough evidence from this pic to be able to determine which way it was previously?

As this set up was working well - and threads aligned - perhaps matching this would give you some piece of mind.

img_20190528_184207_12092.jpg

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Thu May 30, 2019 7:57 am quote
charlieman22 wrote:
Swiss - is the issue that you want to be careful to match what you had before disassembly - or that you are concerned it was backwards then - or both?

In any event - is there enough evidence from this pic to be able to determine which way it was previously?

As this set up was working well - and threads aligned - perhaps matching this would give you some piece of mind.
I've looked at that photo and compared to the studs removed.. there is no way of telling from just that photo which end that is.. I have compared the heat marks from fins on the studs and the discoloration on threads from dirt to almost completely confirm my view that the longer threads were down.

The only problem is that I read that previous thread about stud install, and saw two conflicting statements, one of which said to worry about depth studs put in..then additionally, Jack221 mentioning threads can get stripped if put old ones in the opposite way due to stretching of threads.

After all these very generous responses, I feel the short thread side goes down, when stud has a short thread.. simply because it avoids that issue. As swa45 mentioned, some studs are same thread length both sides, so you just be aware when installing those to not bury the top frame side stud in as hard as possible.
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Thu May 30, 2019 8:56 am quote
I've rewatched some of FMP's videos on using this calculator and I think I understand one aspect of it better.. how adding and subtracting base gaskets affects the PBT field. I was getting confused because some of his videos use another calculator that seems to use squish value instead of PBT, and when he uses this calculator, he doesn't directly say the gaskets should be added to piston field if not decking the top of cylinder, just put two and two together when i saw some graphic he put up at the end of a video that mentioned removing the gasket thickness from the top which to me would translate to him not changing that field.

Exhaust and transfer values are entered as is from most recent careful physical measurements..
PBT is entered as is to top of cylinder, if you add a base gasket, you subtract that gasket thickness from exhaust and transfer port value, but you add it to the pbt value so for example my pbt is -0.71 with no gasket, but add a 0.25mm gasket and it becomes -0.96, because piston is now that much further below top. He does not change the PBT value in the calculator in his videos because he shaves that gasket thickness off the top of the head to keep the squish exactly as before and counteracts the addition of the base gasket on this value. Also, the head measurement does not play into this pbt field in this calculator. It isn't squish, but just the piston below deck and any base gaskets that change that distance... I think?

So I believe this is my correct calculations for if I were to make adjustments with the current 57mm crankshaft (which I am not doing) to hit 176Ex/120Tr/28Bd...

Measurements
Exhaust - Orig: 36.28mm (no base), Adjusted: 34.6mm (0.5mm base gasket + Grinding 1.18mm up towards top)
Transfer - Orig: 47.41mm (no base), Adjusted: 46.91mm (0.5mm base gasket added)
PBT - Orig: -0.71 (no base), Adjusted: -1.21 (0.5mm base gasket added)

Timings:
Exhaust - Orig: 167, Adjusted: 176
Transfer - Orig: 114, Adjusted: 120
Blowdown - Orig: 27, Adjusted: 28
Squish - Orig: 1.85mm (0.71 PBT + 1.14 Head), Adjusted: 2.35 (0.71 PBT + 1.14 Head + 0.5 base gasket)

From the instructions.. squish should be 1.1, which would mean without base or head gasket, I would need to take 0.75mm off the top of the cylinder to get from 1.85 to 1.1.. and for the adjusted setup with 0.5mm base gasket and no head gasket, I would need to remove 1.25mm off the top of the cylinder to get back to correct squish as instructed.

Does this sound correct?

pnp no gaskets.jpg
no gaskets no grinding default setup.

pnp 0p5 base gasket 1p18 exhaust grind up.jpg
0.5mm base gasket. grinding exhaust port 1.18mm up.

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Thu May 30, 2019 9:59 am quote
Re: pulled the stock cylinder off finally
V oodoo wrote:
To learn more about these magical CR80 corks, look here for some interesting discussion: Honda CR80 clutch disk page, what have you got?
They're cheap, even at your local Honda shop, and you can do it yourself for a big improvement on any 7 spring until you go big power & you get the Cosa clutch.

Great thread, I too am learning much.
Thanks for that cr80 plate thread! I barely made it through the first page without feeling overwhelmed with enough information and reasoning than I ever thought possible on benefits and physics of a clutch plate! ha!

I just emailed Dave at Scooter Mercato and mentioned that I will be ordering a BGM Strong clutch with CR80 plates in the fall for an engine upgrade. He said he just started selling them and asked for a link to the specific clutch I was looking to order in the future. I sent him this link and he said he would order it to be in stock and available for when I am ready!

https://www.scooter-center.com/en/bgm8296/clutch-bgm-pro-superstrong-cnc-cr80-type-cosa2/fl-for-primary-gear-67/68-tooth-vespa-px80-px125-px150-t5-125cc-cosa-sprint150-rally180-gt125/gtr125-ts125-gl150-super125-vnc1-11001-super150?number=BGM8298

BTW, I also proposed the stud question to Dave@Scooter Mercato... He also said short thread side into case.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
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Posts: 1209
Location: London UK
Thu May 30, 2019 7:23 pm quote
Short thread in the case is correct. I would wait for the new ones. If a stretched thread goes into the casing it will strip every time.
If you can run the sleeve nut all the way down the thread its not stretched.

You are starting to confuse yourself with these measurements.
The exhaust and transfer measurements are fixed in the metal you don't need to keep adding and subtracting from them. The calculator does that for you.

If your original port distances were accurate, then just the thin base gasket and no head gasket are the best for now. The squish will be really big but will still run.

If you calculate again with a 60mm crank it all works out much better. A tight squish on a 166 (175 on a 60mm) is 0.7mm but anything less than 1.0mm is good. Dont worry about this for now.
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1980 P200E project, 2005 Stella Malossi 166 MKIII
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Thu May 30, 2019 8:18 pm quote
Jack221 wrote:
Short thread in the case is correct. I would wait for the new ones. If a stretched thread goes into the casing it will strip every time.
If you can run the sleeve nut all the way down the thread its not stretched.

You are starting to confuse yourself with these measurements.
The exhaust and transfer measurements are fixed in the metal you don't need to keep adding and subtracting from them. The calculator does that for you.

If your original port distances were accurate, then just the thin base gasket and no head gasket are the best for now. The squish will be really big but will still run.

If you calculate again with a 60mm crank it all works out much better. A tight squish on a 166 (175 on a 60mm) is 0.7mm but anything less than 1.0mm is good. Dont worry about this for now.
Ok.. I have a habit of overthinking everything!

So to use the calculator properly, I am only adding and subtracting gasket thicknesses to the PBT field? and then if i grind the exhaust port up, that is subtracting from the exhaust field... Everything else stays as measured.

-----------------EDIT----------------
FMP has confirmed to me that the better way to use that calculator is as how I just described. Only change the PBT field to account for gaskets, and subtract from exhaust for any grinding up you do.
-----------------EDIT----------------

I put in the 60mm crank with the correct port measurements and got transfer time of 124 and exhaust time of 173 with PBT at 0. I know its getting ahead of where I am at now, just trying to understand everything, so this would mean squish is 1.14 if pbt is 0, so the only option to reducing squish would be to remove the desired amount from the head, correct? And as you said, 1mm squish is good.. so that would mean 0.14 mm removed from the head.

BTW, for everyone following, I found this interesting page talking about port timings and blowdown required for RPM ranges...
https://martysgarage.info/reference/two-stroke-port-duration/
Hooked
Joined: 26 Jan 2019
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Location: california
Fri May 31, 2019 7:27 am quote
Swiss - thanks.
Both sorting out the calc and the link very helpful/informative.
Much appreciated.
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1980 P200E project, 2005 Stella Malossi 166 MKIII
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Fri May 31, 2019 8:01 am quote
charlieman22 wrote:
Swiss - thanks.
Both sorting out the calc and the link very helpful/informative.
Much appreciated.
Np. I'm still chewing on this info at work today, and trying to understand how head gaskets vs base gaskets relate, specifically for if you needed to lower the timings. That seems to be more tricky because more variables would need to be changed in t the cylinder and the head.

Then again..i won't worry myself with that too much cause i don't need to do that.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1209
Location: London UK
Sat Jun 01, 2019 6:39 pm quote
swiss1939 wrote:
I put in the 60mm crank with the correct port measurements and got transfer time of 124 and exhaust time of 173 with PBT at 0. I know its getting ahead of where I am at now, just trying to understand everything, so this would mean squish is 1.14 if pbt is 0, so the only option to reducing squish would be to remove the desired amount from the head, correct? And as you said, 1mm squish is good.. so that would mean 0.14 mm removed from the head.

BTW, for everyone following, I found this interesting page talking about port timings and blowdown required for RPM ranges...
https://martysgarage.info/reference/two-stroke-port-duration/
With the 60mm crank you're going to need to do a little Dremel work to get the timing right but should be easy enough. This will negate any rework of the head.

Although these websites are interesting a lot of this porting data is just copied from elsewhere. Knowing what works for scooters takes time and experience and most tuners won't tell the whole story.
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1980 P200E project, 2005 Stella Malossi 166 MKIII
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Sat Jun 01, 2019 7:16 pm quote
Jack221 wrote:
swiss1939 wrote:
I put in the 60mm crank with the correct port measurements and got transfer time of 124 and exhaust time of 173 with PBT at 0. I know its getting ahead of where I am at now, just trying to understand everything, so this would mean squish is 1.14 if pbt is 0, so the only option to reducing squish would be to remove the desired amount from the head, correct? And as you said, 1mm squish is good.. so that would mean 0.14 mm removed from the head.

BTW, for everyone following, I found this interesting page talking about port timings and blowdown required for RPM ranges...
https://martysgarage.info/reference/two-stroke-port-duration/
With the 60mm crank you're going to need to do a little Dremel work to get the timing right but should be easy enough. This will negate any rework of the head.

Although these websites are interesting a lot of this porting data is just copied from elsewhere. Knowing what works for scooters takes time and experience and most tuners won't tell the whole story.
Messing with the calculator I'm guessing dremel work you mean is approx. 1.5mm from the top of the exhaust port to get exhaust timing to 179 and blowdown 28?

I'm sure info on sites like that are general, but it all helps, as long as it's not grossly misinformed!
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
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Location: London UK
Sat Jun 01, 2019 7:33 pm quote
Wasn't thinking quite that much but you're on the right track. Put too much power up the top and you'll see your fuel figure plummet.
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1980 P200E project, 2005 Stella Malossi 166 MKIII
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Sat Jun 01, 2019 7:45 pm quote
Jack221 wrote:
Wasn't thinking quite that much but you're on the right track. Put too much power up the top and you'll see your fuel figure plummet.
Yeah, I'd like to keep mpg within reason, also don't need the highest revving engine. Just hypothesizing more to understand the process and decision making. I was thinking those timings seemed a little high by default, but with lower end of the desired blowdown. Either way, I need to get the kit on and start riding it around my area first to get a sense of how it runs first, then start thinking about how to change it.

Hopefully by Tuesday this thing is running again.
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1980 P200E project, 2005 Stella Malossi 166 MKIII
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Tue Jun 04, 2019 10:18 am quote
I got the studs late last night, so I put everything together today. New studs in, and I slowly and carefully started to torque down the head bolts, starting with 10 ft lbs in criss-cross pattern.. then 11 ft lbs, then 12 ft lbs. Haynes manual says 9.5-13 ft lbs. The torque wrench clicked at all nuts on 10 and 11, but on 12 ft lbs one stud/bolt wont click.. just keeps spinning. It did make a loud pop sound that vibrated through that stud. I took the stud out to see if it was broken which it wasn't.

Does this mean that hole is stripped and I need to take everything apart and re-thread that hole larger? If so, what size larger? Or is it good for now since it's holding 11 ft lbs on that one stud and 12 on the other?

Just my dumb luck if stripped thread.. I am so careful and take forever to do these things first time specifically because I don't want crap to go wrong!

IMG_20190604_130140.jpg

IMG_20190604_130829.jpg



Last edited by swiss1939 on Tue Jun 04, 2019 5:57 pm; edited 1 time in total
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1980 P200E project, 2005 Stella Malossi 166 MKIII
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Tue Jun 04, 2019 10:27 am quote
by the way, I re-measured PBT once I got the cylinder back on with a 0.25mm base gasket. Previously I measured by turning the crank until piston came to rest at the top then measuring. This time I stuck the measuring gauge in the cylinder and turned crank over to let the piston push the measuring gauge to its top dead spot through its whole cycle from below to beyond top dead which I think is more accurate. PBT is now -0.38mm.

This means port times are 166 Exhuast and 113 transfer with 27 degree blowdown 1.52mm squish
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1980 P200E project, 2005 Stella Malossi 166 MKIII
Joined: 20 Jul 2018
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Location: Staten Island, NY
Tue Jun 04, 2019 5:33 pm quote
I went to Lowes and bought a set of metric tap and die with the correct m7-1.0 tools, then cleaned up the threads on the case and new studs. Re-installed using 10 ft. lbs of torque, got the click and stopped there.

Put new jets in and it started up with a little adjustment of air mix screw and idle screw.

The jets included with kit are AC140 BE4 115MJ and the 52/140. I installed them all except I went up to 116MJ just in case. I also switched to BR8ES plug as it said in the included instructions. Only thing I didn't do yet is change tank of gas to higher octane as instructions stated. Currently at 87 octane.

It is extremely rich. I am wondering if I should be at the higher 115 main jet, when the instructions say to use 105 main jet for standard ignition timing. I have not set my timing to advanced 18 degree. I left it at stock.

Also, what I have noticed in a short 5 mile drive around the neighborhood is that it sounds normal when idling, but when revving and hitting the throttle there is a much more mettalic rattle than previously. I am wondering if this is normal for break in time, or if there is cause for concern over the sound. I have a quick video of one of first startups where you can kindof hear the metallic rattle under throttle. I did not record a better audio file of it yet. Part of me is worried something broke inside case from that loud pop sound from the stud. Wondering if maybe I should just bite the bullet and take the engine apart and rebuild now making sure nothing is wrong internally.

https://photos.app.goo.gl/wE5FSY2iMKckadpx6

IMG_20190604_205457.jpg
AC140 BE4 116MJ and the 52/140

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