Modern Vespa

I’m jealous. Epic find.

The floor would actually be really easy to replace ,with have the floor already deteriated away , you're half way there.

Woohoo!! New project!!
-Handlebar- check.
-Wide-body- check.
-Electric- check.

This is going to be epic! Full circle back to what the leaner was originally slated for. Lots of room in the belly for all the go-fast, electromotive force goodies!

Last edited by poidog on Sun Aug 02, 2020 11:54 am; edited 1 time in total

In electric wheelchairs, hub motors are great and there isn’t really any drive line loss or gearbox maintenance. There called gearless brushless in those setups. Not knowing anything about a midmount motor I would pick hub.

I would put a big two stroke in there. Like god intended.

You better rob a Tesla or something worthy for this.

Christopher - I'm researching options.
Reason to consider mid drive would be if it provided better top speeds.
Not sure it would - but keeping mind open.

Pheas' - it's a tough one. My passion is for the 2 stroke - but I'm taken by the challenge of making something magnificent with electric that is the real deal to ride.

Bonus: I am hopeful that the electric's twist and go nature might even entice my wife to join for a ride to the pub.
New thread will explore all the options and provide space for everyone to yell at me about the decisions.

60MPH or bust.
-CM

Going to be lovely. The wife might prefer to plant flowers in it but it is recoverable. Shipping it to Craig would have the best outcome but failing that it's going to be a challenge. Just to get rolling. Will be cool as electric. Going to be interesting.

Wonder what Craig charges for house calls.
Allstate will rest a bit while I focus on the orange unicorn's motor.
And with that - the cylinder is off.
Nothing like a tear down to get the closest of looks.
Few interesting observations.

The "ping" marks on the top of the piston are proud - not indented.
You can see that from the shadows cast in the direction of the exhaust port - as carbon builds on the back sides of them (looks like moonscape).
In other words - it looks to me like that is aluminum from somewhere else rather than missing aluminum from the crown.
Anyone want to weigh in on that?

Speaking of aluminum from somewhere else - below the compression area - some nikasil chipped at the end of the boost port window on the skirt.
I didn't do any chamfering - as it was already done at the factory (I think).
Damage down below the piston rings is new to me.
Anyone wanna weigh in on that one too?
Treatment - Fine sand paper drum and polish to get rid of any edges?

Malossi cylinder holes are bloody tight to the studs.
That's a problem for me - and a mystery of design given the propensity of 4 corner seizes these cylinders are prone to.
My oversized cylinder studs are a no go - it will have to be machined to accept.

So no reconsidering order of events.
May clean up nikasil chip (if possible?) and do a bit of tuning work on the BGM and throw it back on.

Hmmm.


Malossi stud holes are small. Wont accept my oversized studs - what can I say.

Piston top. golden but not quite to edge. "ping marks" might be aluminum from below?

Yikes! did I do something (or fail to do something) wrong? How can I dress this?

Don't SIP supply special bodge studs with an 8mm thread but 7mm shank and 7mm thread at the top? I think they do.

About time. BGM was running ok ish but not quite there.

Skirt seize will smooth off. Doesn't matter. Not mint anymore. This from the running rich low down. Makes the piston rattle. Always opposite exhaust, sometimes there is a weird rounded edge on the skirt too. Clean it up and carry on. A few mm to come out of that exhaust port as I remember. 185 is the upper limit.

Acid. I use hydrochloric acid - generally used for cleaning mortar of new brickwork - and it works a treat. Put it on with a rag and scrub with a small wire brush. Does not harm the nicasil. Wash and re-apply as necessary.
Wear a mask. Especially when you scrub with acid! Lots and lots of ventilation as well as gloves, glasses etc - probably don't need to tell you. That sounded vaguely familiar, but I couldn't find anything on SIP. When I say anything, it brought no results at all under cylinder studs, studs, cylinder bolts - but did show exhaust studs under that last search!

At Scooter-Center they had these. I wonder if they would help CM? still M8 but obviously thinner in the middle. Or won't M8 fit at all? They are 10mm longer than regular M7 studs.
https://www.scooter-center.com/en/stud-m8-x-150mm-piaggio-used-for-cylinder-piaggio-leader-125-200-cc-lc-9901125?number=9901125

Thanks guys.
Help always appreciated.
My stud situation is a bit of a mess on these cases.
I replaced one with an 8mm stud and a time cert.
I hated that the other studs were different - but I hated even more having different nut sizes holding the head - so I used the bodge fix it studs you guys are referring to - 7mm one end - 8mm the other and FLIPPED THEM.
I liked the 8mm threads on the bodge studs better as well - all my 7mm stripped like butter.

So current set up has 3 @ 7mm going in to the cases - with 8mm heads.
1@ 8mm in to case and at head end.
However, 8mm threads won't fit though the Malossi.

I could fix that by going back to stock studs for the three that have the 7/8 mm config - but the one 8mm stud would still need to be bored larger.
Not sure I have a fix for this other than having the cylinder bored to a larger dimension hole.

I'm looking at my BGM tuning options now so I can put it back together.
Little twist in the road I wasn't expecting - but think it will be ok.

Re BGM Port Timing
Here are the numbers so they are fresh.
Currently with .2 base gasket I have 123/173/25.
I can use a .3mm thicker base gasket - making it .5 total.
That will give me 124.5

If I then sand the top of the ex. port 1mm, I will get 178. 1.5mm will give me 180, and 2mm will give me 182.

I am going to target 1.5mm of sanding on the ex. port with a .5 gasket to get:
124.5/180/27.75

How much meat would boring everything to 8mm take out of the cylinder? Not a lot there to start with it looks like. I'd personally make that last option.

Can you sort the odd one out on your case back to 7mm? Or sort a 8mm => 7mm custom stud?

Or get new cases?

The 7mm studs are ok if you use deep head nuts. So, get them all back to 7mm.

To re-cap, you have three 7mm threads in the case and one 8mm. Already running 3 bodge studs in reverse and a P200 stud.

If this is correct it's easy. 3 normal 7mm studs and a bodge stud with the 8mm in the casing. Is this it or did I miss something?

For the BGM and your needs (torque) you need over 180 but less than 185 (Just between us this is like a magic number). 124.5 is sufficient. Can be adjusted with head gasket, so that won't affect squish by much that matters.

Another candidate for my signature. Nope - actually - you nailed it.
Think that will work.
As Pheas' notes - not much meat to work with so lets hope so.
Some of those nice tall shouldered nuts that SWA posted a few pages back would make a nice addition as well. Don't worry - I won't tell anyone then.
Will take it up min 2mm then - which will get us in the 182 range.
Should be able to hold squish at .8 as this head fits inside the cylinder.
I have a 1.5mm head gasket on it now - pre tuning.
I can take .3 out of that and put a 1.2 on to hold squish where it is.


I've started the porting - using the skirt to warm up with (shhh. don't say it).
Got bored trying it with just sanding discs after about 10 min - and moved to the: sand down the nikasil surface 3mm then grind down the aluminum meat with a bur - approach.

Managed not to mangle it too badly. Still need to take it down further - but need to do the window on the other side first so I can get the tool lower on this side.

Nice to see porting going on. This one still Running first? Makes more sense to stick with this order. Once on the Malossi you won't go back.

So hopefully bodge stud works for the Malossi. Opening out the holes was last resort. They were reduced for good reason.

BGM progressing. That lower cut can go full width of the window. It's lower than the gasket face, so not blocked by the base transfer width. Should be enough metal but well worth a check.

182 as original plan is good. Going to feel like a different kit and wondering why BGM left it restricted. Exhaust port to hold the same width and shape, just higher.

CM, your need for reliable power points towards a new set of Malossi V-One (or VR-One) cases to go with that MHR kit

I like spending other people’s money and time. 😁

That would kill the visceral joy I feel as I blow by some proud P200 owner with my 1961 bodge 150 cases (and a sidecar hanging off the side!).
I know I can get there with blind cash - but it would kill all the fun and I would have nothing to write about. See above.

🙂

Cylinder porting is done.
Will lift cylinder .3mm so that it goes from .2 to .5 base gasket.
Using the calculator with the BGM drop in cylinder is a science project.
Here are the numbers - so I have them recorded:

Actual measure: 38.03
.5 base with 1.3 head gasket and 3.97 head insert (.8 squish) = -3.26
38.03-3.26 = 34.77
= 124.5/181.5/28.5

BGM will go back on with these higher timings and larger exhaust.
Some pics below of the process.
Couple of notes for anyone porting a nikasil cylinder.
My method:
- sand down the face of the nikasil to reveal the aluminum underneath.
- Grind the aluminum down
- Repeat step 1
- when I got close to where I wanted it - used 240 grit sand paper on small Dremel drum to clean it up and bring it to the line I wanted to sand it to.

I also used an old piston ring which I glued into place - as a guide. very helpful. Just cleaned it with acetone first - then super glued it in place and started sanding. you get sparks when you touch it - so its pretty accurate.


240 grit or higher - take the surface of the nikasil down until the aluminum substrate is exposed

Remove material with the grinding bur

Nostril effect - more than enough feed now for the transfers - likely 2x the opening vs stock

Gluing the old ring in place as a guide

Ring set 2mm above ex. port - then just got out the Dremel and sanded away. With just 2mm - no need to risk using a bur. just a sanding drum

Did the piston need any work? The side transfers should be fully open at BDC and not blocked by the skirt. The boost hole can need raising up to compensate for the 60mm crank and packer.

Side ports might be twice as big as original but looking at that overhang, could go much bigger but would need cases cut to match. The width is not parallel with the stub windows, this can be done while leaving the cases as they are. As this will still not rev that high (less than 8000 before peak), transfer flow is less important but bigger does help the torque at mid rpm too.

Any picture of the final exhaust port? Nice and straight?

Width of skirt window opening is already wider than transfer ports in cases - so a bit more would not hurt anything - and would increase inlet surface again.

Hard to believe it needs more - they are enormous compared to where they started - but perhaps I will "refine" their width a bit before chamfering.
Without having the cases split and sitting on the bench - there is some loss of finesse between the ports in the cylinder skirt and the cases - as
I can not grind and polish in situ.

Boost port - I took down but only to deck - rather than to dividers - matching the Molossi MHR. For what ever reason - neither the Malossi or BGM have the boost port skirt opening as deep as the the transfer ports.

Exhaust port came out factory straight and symmetrical - was pleased with that - still needs to be chamfered. Pics to follow.

Piston - untouched still. I will match any blocking overhang.
Question - what about the little window on side that is not drilled out on the BGM? Size?
Why did they leave that unpunched? Purpose?

That piston is unlikely to need any work. All looks big enough for anything. Why the piston cut outs are so big and cylinder so small is a clue to their thoughts on tuning.
If you did the boost hole in the skirt the piston can be left. Blanked indents are just for the name, lightening, friction, strengthening, vibration, they don't line up with anything.

No need to touch the casings. With the base cuts window width they will be less relevant for your needs. More flow will be up the sides of the piston.

Timing is on the low side at 181.5 but will be way better than before in any case. Going to be faster but still 20 degrees from dragster.

I was positive that you said you had cut the "dams" (or whatever you call the transfer covering bits) away already? What does the case look like in that area?

Love the idea of gluing the ring!

Well - that can't go un-flagged!
The BGM piston also has those deep indentations on the side - so at BDC - your case cut outs are made nearly 50% deeper in volume when the piston aligns with them.
I assume that this is one of the ways that they created a great plug and play solution - as the piston indents act as case porting.
What's your theory on their thinking you refer to and how it biases? The BGM comes with the secondary transfer port (the feed located in the skirt area) covered by aluminum - so that it will fit cases that have had 0 porting to them. I did some very minor grinding to remove what I referred to as the "hood" - but did not take the skirt height down at that time.
Pictures provided from Swa's BGM build thread show his before (hood marked in blue) and after shots (thanks Swa!)


Blue is marked on what I called the hoods. My cases have been previously opened in this area so they would have been feeding in to the hood and creating turbulence.

Here is Swa's after he ground off the hood.

Mine with hood removed and skirt taken down to divider so that it is open from the side as well. The BGM piston has big indentations on the side - adding significant volume to the case cut outs at BDC - which I am a big fan of.

The width of those piston side cut outs would seem to dictate that the base ports should be the same width. Depending on the engines base gasket area those side ports could be made square, hoods completely gone and opened out to within 2mm of the gasket edge. This benefits all rpm ranges but the higher rpm the most. Regardless of transfer port size all of the mixture in the crankcase at the end of the inlet cycle, gets squirted up on the downstroke. What makes torque is increasing size and duration to minimise turbulence and slow down the flow rate, as to flow the same volume with more control. This sounds like crap but it's actually everything. At mid and high rpm high turbulence and clashing streams cause mixture loss and incomplete scavenging. The BGM is good as limiting loss with the low angles. Especially on our scooters there is no too big for transfers. Your cylinder could have a while longer on the bench opening out the windows and the transfers but seen worse run great

Any picture up the exhaust?

Ex. port below.
No wizards sleaves here.
🙂

My cases have limited meat on them.
Confounding it is that the Malossi has a totally different shape of transfer port (similar to Quatrini) down at the base.
I will have to add some JB weld to create sealing surfaces already.

I may finesse the transfer ports a bit more at the bas before I call it a day.
Since the cases seem limited - it may pay more dividends to increase the depth of the porting to open up the "sides" rather than make them wider - where the cases will just block off the work.

I will also look at some subtle adjustment to the cases as my cylinder skirt openings are already wider then the cases are at the back - where I do have some meat left.

Now - about that ex. port:

I wouldn't touch the casings at this stage. I would open the cylinder base though. Would gain a few mm even though the base doesn't line up. Important not to go outside the gasket line. JB weld great to fix but shouldn't be intentional here. Casing blocking windows is near irrelevant, the bigger flow goes up the piston.
Raising the cut outs up the cylinder means they will get limited by the piston skirt and also shorter transfers are more turbulent. It's a compromise.

Exhaust port. Looks good no wizards sleeve here. However, looks like you might have raised the middle and blended it in. This means the radius is now bigger, meaning mid and max power just reduced. If you compare rubbings with before we can see. BGM did a good job with the top shape, so we know the rings are good for it. Raising the sides up first before working on the middle cures this.

Missed this - was in the garage grinding the casings.
See below. Did a bit more of this too.
See below. Didnt quite follow - can you clarify? See tracing. I have gone back and increased the flatness since the first photo.
I tried to keep generally the same shape - but perhaps I did not take as much from the sides increasing radius slightly. Rubbings done after chamfer. Hard to believe at 2MM taller and .3mm lower - it could possibly produce "less" power!


Taped it up

Ground it away

Opened up a bit wider in the area above the bottom of the finned portion fo the cylinder

Rubbing. Hair less radius in the corners - but mostly flat. Perhaps Ill chase the sanding drum a touch more in to the corners before re-assembly.

Here is a re-shoot of the ex. port with a bit of clean up that's been done

I would cut out the last of that overhang on the side transfers. Leave the gasket on the cylinder and cut under it until the outer edge is smooth. It's blocking quite a big area.

When at BDC the piston will be in the side window. Cutting higher than the piston cut out has arguably no benefit.

With the exhaust port, draw a vertical line up each side with a Sharpie and grind straight up the side 2mm, then round it over. Should be the same as the original profile.
Leaving this big radius will reduce top end power, not from how it was but from how it could be. When firing over 100 times a second, it doesn't take much to restrict the exhaust.

Like so? Hot Rod Al’s handiwork.

There is no meat on my cases for this. that "overhang" is what I use as my sealing surface. Couldn't work out what you meant. Gasket slipped on to cylinder so it sits on base - check. Outer edge of what? I probably should have put a hole in the indented area I noted previously to take advantage of that high cut. That said - the piston on the BGM has that big indentation up past the piston ring - so that higher cut should pay dividends? This would have been smart for exact match. I glued a piston ring back in and did one final pass at the corners. It would have fallen short of the perfection you were pushing for - but the effect of your pushing left it much closer to the original shape than I had it.

I say in the end - because momentum took over and I kept going until I had the cylinder back on and torqued. So perhaps less than 100% but probably the right place for this cylinder as a work horse - with the Malossi in the wings.

Hondabond is curing - will test for leaks tonight - and if all well - head will come back off and I will finesse a head gasket at 1.2mm to keep the .8 squish.

SoCal - Hotrod did some mighty pretty work. I think Jack was referring to the cylinder rather than the cases. The cases you show have a lot more meat on them than mine. See below.


This is my approximate sealing surface. If I take away the overhang there will be nothing to seal to - the cases seal to that overhang.

I post these three pictures in a futile effort to defend myself in anticipation of Jack's... lets just call it... "disappointment".

Got close! tho I will grant - these motors are truly machines of millimeters.
Honda bond is doing its job curing.
Just did a quick pressure test - all good.
Should be on the road with it tomorrow.

All these posts of 123 of this and 182 of that can be - less than enthralling.
What I am excited to see is: what are the real effects of lifting the cylinder and porting it.
Have both good data with the GSF Dyno and significant time in the seat driving the BGM.
Kinda excited to see what the change feels like/ measures.
We'll see!


left is original. middle was first attempt before critique. right is as installed

We live about 800 miles away from each other, so i know you're not talking about me...

Give it time...
🙂

Exhaust port now looking more like before. This will go now. And by go I mean you'll struggle to believe it's the same cylinder. Will be well worth the effort of going in again with the Dremel. Seems like a small detail but tuning is all small details.

This will need to be a few rods richer at the top but none at the bottom. This time out it will be less tolerant of the lean experiments. Be sure it's rich enough at the top while keeping the low throttle smooth. It's going to run hotter (more power and no extra cooling) and that means more risk.

No need to run in, so straight onto the Dyno runs

Ok - busy day with pesky paying job - so didn't get to scoot until late in the day.
Issues with phone app kept me from doing proper speed run recordings.

Put in a richer rod - by 2 rods.
Felt spluttery.
Temps barely over 200 - would have been 40-50° hotter minimum previously.
Sensation and temps suggested rich.
Moved back to 1x richer rod.
Better - temps still relatively low.
Not much oomph in fist 1/2 throttle.
Went back to original rod - best of the lot - but possible it is lean at top based on Jack's comments.
Will plug chop and confirm where WOT needs to be to assure I am not lean.
Both the one richer rod and the original one produced 8500RPM in 3rd.
Up 300 RPM from prior max.

Will sort out app and tune in with Dyno runs tomorrow.
See plug pics below.
Clearly the richer move was too much - however - plug is showing an average so nothing to go to the bank with. probably too rich down low and either just right up top or too lean.

First impressions - scoot scoots - but jetting is dulling the lower end.


Plug after Hwy 1 ride. Milk chocolate

Plug after todays short 3 short runs. metering rods: 2x richer, 1x richer, same as hwy run ride. Milk chocolate is gone. Too rich somewhere in the the throttle range.

What kind of weirdness is this? Should have needed richer at WOT. Could be something to do with the smartcarb or could be that now the exhaust is working better there is less mixture loss. Either way the plug doesn't lie, that needs leaner low down. Just focus on WOT until it is closer.

I would think it will rev a bit higher than 8500rpm. Peak power should be 7500rpm so overrun should be slightly more than 8500rpm. If not spluttering it could suggest it's gone richer at the bottom and even leaner at the top. Try to get splutter at WOT and work back from there. Forget about what happens at less throttle than WOT until you think WOT is good.

I’ll attack it more robustly tomorrow.
The plug shot was interesting.
It changed with very little riding.
That alone was a surprise to me.

Agreed - establish WOT first is the plan. Motor is tight. Squish is right. Should be able to use top speed to narrow it down to 2 rods, with one Move leaner or one move richer Causing fall off. Then plug chop and realize that the richer rod is the right one for WOT.

🙂

Will then look to use adjustment of clicker to dial in bottom end and see what we get. Also thought I would see 9k rpm max. Leaves me wondering if it’s still rich there (or not...).

Only one way to find out

I was under the impression that when the motor is new that wot is a no no. I need to establish a break in plan for my motor.

It’s not a new motor, he pulled apart a basically stock BGM top end, carved it up added some gaskets for timing and put it back together.

Christopher pretty well nailed it.
Rings and cylinder were already broken in together.
I did pull the cylinder off - but only to change the size and shape of the ports - and to put a gasket under it - to make it a bit sportier.

With that said - I have a first look at speed run I did at lunch.
This was done with an EQ 30 - which is 1.5 rods leaner than how I had it jetted with the stock BGM.

I did a handful or runs - moving from a 28.5 up to the 30, and turning the nob to make it as lean as it would go on the 30.
With each run as I made it leaner - the motor hit higher RPM/top speed in 3rd at WOT.

This run peaked at 8700/8800 RPM - the highest rev I have had this cylinder to - using the EQ30.
I will plug chop this one - and also run an EQ31 run to see if I have maxed out the Revs or if it is still a hair rich at WOT.

HP is up at peak - but I've swapped grunt under 4800 RPM - at least with this jetting.
Temps remain significantly cooler than with prior set up.

Question - tho I have asked this once - want to get it clarified.
When you change your base gasket - does that move your timing?
Is it possible I am running it retarded - thus not seeing the heat at the head?
Surprised it is demanding both leaner jetting and running cooler after tuning.