Modern Vespa

Timing was off a bit, stator was on "A" which should have been 23°. Set the Kytronik to "0" during the testing which is supposed to be no change or a pass through. It was actually 18° when checked with a timing light. Timing was also fixed through the rev range so I know I selected the correct one. It has a KyTronik, and was set on a curve with 8° retard. So it was going from 18°-10°.

I spent some time checking and finding "0" or TDC. I used my digital angle gauge found "0" twice. Even checked the angle when touching the piston stop and it was the same in both directions. Same as you do when centering and zeroing a degree wheel.

Rotated the stator to the end of the slot was able to get 6mm movement. Checked the timing and I'm now at 24°, turned the Kytronik to "4" and the timing moves from 24° to 18°.

Now we'll see if she generates a little heat, wouldn't get up 190°F.

I have found Kytronic 0 to be not quite zero. Might be a degree or two out. Can quickly wire the stator to CDI to confirm. If yours is, no need to change the timing. Just switch to 6 or B or similar.

Physical timing marks were way off when I checked, with a digital angle gauge and timing light as noted in my earlier post. Here is a Dyno comparison with a before and after mean, just a little bit of a difference, torque up 15%, power up 22.9% and shifted to the right about 1100 RPM to 6000.

Temperature still never went over 200 degrees F, she runs in the high 180's. Idle she gets up to about 150 degrees F. Time to perform a plug chop or two, and start leaning here out a little I bet. The odd part is the only spot she is so rich that she misses or 4 strokes as some call it is at 1/4 throttle. That really shows up on my AFR meter also. AFR drops to around a 11 and she starts to miss. The rest of the time at WOT the AFR shows up between a 12 and 13 which should be ideal.

I was running at 1/2 throttle in third gear for a few miles in third she never got over 200F.

I tried running 3/4 throttle for a few miles not any better.

When I pulled the NGK B8 plug at home it is a little black but not wet or oily.

Time for a few WOT plug chops, makes me want to lower the needle a notch and put in a smaller power jet I have sitting in a box before I even start. My problem is, I don't know if I trust the temperature gauge. The AFR meter had been really close with my old setup, maybe this setup it wont be. Maybe the built in Temperature gauge is off, may try the Trail Tech again, just to see.


Dyno comparison with a before and after mean.

Spent some time looking at the present power and torque curves and my desire to be able to ride at a consistent 60 mph or 97 kph. I know the fourth gear was swapped for a closer ratio fourth, 36 tooth I was told. This also matches the 6000 rpm at 60 mph I was seeing using this website.

http://gearingcalc.free.fr


Switched fourth to 36 tooth and put in a 100/89-10 tire. That tire size matches the measured perimeter. Ordered a DRT 24 tooth clutch gear, currently have a 23. That should drop my 60 mph rpm to 5750 and we'll see what that feels like. Should move me into a little more torque giving up a little power. That 6800 rpm or a little less over rev just doesn't feel right so close to desired speed. Crack the throttle a bit and you can feel it.

Made a little progress lowered the jet needle to lowest point and put in a 70 power jet vs 80, power is up 5.2%, torque is up another 3.9%.

The temperatures noted below were riding a few miles up and down small hills.

Lowering the needle got me up to a 225F temperature range for 1/4 and 1/2 throttle. That's an improvement from less than 200F.

Need smaller main jets, running a few miles at 3/4 she cooled off instead of warmed up, also wouldn't rev out to 7800 rpm.

Now if I keep the throttle below half, the motor will rev out to over 7800 rpm vs 6800 rpm previously.

Today per Jacks suggestion to simplify jetting I plugged the power jet, Stella revs out a bit further. A small gain in peak power also and more over rev. I'm going to try a leaner main jet to see what happens. Currently at a 260 next available from Mikuni is a 250. Temperature did get up to 243F or 117C today up a small hill into a head wind at WOT in fourth.

I think I may need to raise the needle a notch, adjust 1/8 to 1/2 richer, not much color on the plug. It is a new plug, I also put a NGK cap on with no resistor and am using a resistor plug, easier for me to get the plug type I wanted. The resistor type are stocked in the auto parts stores here. Most of the riding was at no more than 1/2 throttle. Temperatures are still nothing to worry about. I think the aluminum is harder to heat up than my old cast iron DR.

One thing I have noticed with this head on spark plugs is that you can see the color on one side is different than the other. Guessing it the side being shielded or shaded by the head shape. Makes me wonder what the centrally located VRH head would look like.


Forgot to include there is about 15 miles on that plug.


Same jets as previous just plugged the power jet

Here's a few more suggestions to make this process quicker and end up with less damage.
Leave the power jet blocked, you're not ever going to need it.
Take out the main jet and leave it out until every other jetting position is perfect.
Fit a pilot jet that you know for sure is one size too small and can only take 1 turn on the airscrew before it weak bogs.
This leaves you unhindered to focus on the diameter, length and taper.

The pilot screw is about two turns out right now. If I turn it in one turn the idle slows and she will die. About one turn back out and she is fine. Do you still think I should try a smaller one?

I'm going to have to work with the needle jet and jet needle I have for the next few weeks at a minimum. I've located a store called Allen's Performance, in the UK I believe, I am trying to get some information from them. They are a stocking dealer of the 622 series needle jets I have, emailed them today. waiting to hear back from them. I can get needle jets in .005mm increments from what I have now. Found several sources for jet needles, need to measure what I have, as I haven't been able to find a source with dimensions for factory jet needle 5EL68.

I can't say I'm unhappy with how she runs now, the only driveability I had was four stroking at 1/4 throttle . Lowering the needle to position 1 knocked out the four stroking I had at 1/4 throttle. I think thats where tuning the two will help.

Looking at the plug I'm still trying to decide if I went to far and should try position 2 again and see how dark the plug gets. I know the middle position left me with a black soot covered plug with build up, and four stroking at 1/4 throttle. Thinking about it, I'm not sure I shouldn't try position 2 again as my timing was way out.

I also have main jets I can use at the moment. I know my AFR meter shows my AFR dropping into the low 12's at wot throttle in third. That is also the point I can feel her start to miss at 7000 rpm. That could just be me bumping against some limit and unburnt fuel. That's why I wanted to try a step leaner on the main.

Also not sure I want to get to in depth until I decide on a exhaust pipe. The SIP road XL didn't get good reviews, compared to alternatives it was tested with. Seems to be better boxes for torque such as a TSR vortex or a BGM touring, 15-20% more torque in the lower rpm.

Also want to hook carburetor intake up to the hole in the frame to pull cooler air in. I'm sure that will change the jetting again.

That should be enough miscellaneous rambling and notes for today.

Problem with these more professional carbs is there are so many many variables. Carb can go rich lean, rich lean as you open the throttle to WOT. Even with great experience setting up an unknown carb to factory smooth is a challenge.
Being way over rich can do damage in the same way lean does. With a good selection of parts this could be done in a few days.

As I said pilot jet should be so lean it will run too rough with the airscrew open more than one turn. Change your jet to one much smaller.

Removing the main jet completely and running without one removes another variable.

This way, all focus is on the difficult part which is diameter and taper. Length is easier once these two are known. Main jet and pilot can be adjusted correctly later.

Bellows, exhaust, fuel pump, float set up etc. All change the jetting but not so much compared to how it is now.

With the temperature being so low it's clearly not good. When putting a bike carb on a scooter, it's not unusual to change every part. Trying to ride to hard before jetted in is going to wreck the engine.

I've got smaller pilot jets on order, and several jet needles, I have a 27.5 in there now and a 25 on the shelf. Should have them by this weekend. Should be able to experiment a bit on Monday. Not having anyone local to get some of these parts from, means it all takes time and patients. I found a local source for main jets. They work on snowmobiles and Norton motorcycles.

Orders jets and needles from this company.

http://www.nichecycle.com/ncs/categories/carburetor/mikuni-parts-by-category/jettting-tuning/needles.html

5N13
5E75
5F3
5FL7
5L1
5DT49
5DP7
5FP17
5FL14
5DP10
5CD20
5DJ8
5J11


Once I put in a small pilot and remove the main then what?

Mikuni jet chart Sudco.pdf
Description:	Here's a chart with jet sizes listed	Download
Filename:	Mikuni jet chart Sudco.pdf
Filesize:	1.16 MB

Next is diameter. Mark the throttle grip so you know where quarter is. On a mikuni the diameter is changed with the atomiser. Select the atomiser to make slightly under 1/4 throttle correct. This will affect the pilot and with every new needle tried it might change.

We'll see if Allen's Performance comes through with deilvery. I paid them using PayPal and my Visa. They had smaller needle jets to help with the first 1/4.

General notes from riding yesterday. The power jet is still plugged in both ends. I know you don't care for AFR, but for me it is a good relative indication of where I am, and if changes moved in the correct direction. Comparing to my plug for instance a 13.5 or so currently is a little lean and plug chops verified that.

I know I can lower the 5EL68 needle to position 1 to get a good idle to 1/4 throttle feel and afr of about 13. Leans out a bit between 1/4 and 3/4 13.5 or so. Pictures from the above plug, WOT in third gear is rich, AFR drops into the 11's. 4th gear WOT cruising short period up a hill to see numbers was around 13.2. Still not generating much heat. Did get into the 240F area at one point.

Position 2 the AFR is 12.4 a little rich between idle to 1/4, and causes missing or 4 stroking. The 1/4 to 3/4 has better AFR around 13. WOT in third still rich into the 11's. Fourth gear WOT, short period up a hill around a 13.2 still as expected. Didn't see any temps over 200F or so, the richer low end did cool things off a bit as expected.

Out of curiosity I downsized from a 260 main to a 250 and it didn't really help with the third gear going rich at WOT. Fourth gear cruising WOT still around a 13.2. Still not getting hot.

I'm wondering if it's the initial bogging when opening the throttle WOT from 2300 or so rpm in third causing the rich afr?

Thinking I may put in a EGT gauge to see what that looks like. CHT can take time to register where a EGT sensor is smaller with less thermal load should show a quicker change.

Waiting on my 24 tooth gear, that may help generate a bit more heat as this will put more strain on the motor. Kind of like lugging in a lower gear with less air moving for cooling etc. I know fourth gear has been lowered with an extra tooth, this matches the rpm and speed that I'm seeing. Right at 6000 rpm at 60 mph, should drop it down to 5750 at 60 mph.

Should have some free time this weekend, and am thinking of the following

0.5
Install 24 tooth clutch cog that should be here. Take Stella out for a ride, see how she runs, get a few dyno runs, update GSF dyno numbers for gearing and make sure power and torque numbers are the same as before.

Might just pull the pilot jet here instead, and put the 22.5 I have in and see how it works and adjusts.


1
Open the engine casing boost port up to match the cylinder boost port size.

2
Widen the exhaust port to about 48mm. A little shy of Jacks maximum recommendation of 54mm but give a guy a break. Looking through here I went to about 60%, with thinner rings it was recommended to go wider, 48 mm is 70%. Leaves a little room for rookie porting mistakes, if I mess something up I cant fix it if I'm to wide. Leaves me room if I go over and end up at 50 or 52mm.


3
Take Stella out for a ride, see how she runs, get a few dyno runs in to see if there is an improvement.

After I make sure that I am back to normal and didn't create any other issues.

4

I have smaller pilots in my hands so I can lean her out at idle, currently at 25 will go down until I cant turn the air screw out more than a single turn and have idle issues. Might be going down from a 22.5 to a 20 if needed.

While I have the carburetor bowl off I will remove the main temporarily.

5
Jet needle, without needle jets at the moment I have a few options. Hoping Allen's Performance shipped them.

One - lower the needle to position 1 from position two, this leans out my idle to half throttle and gets rid of the 1/4 throttle richness at transition (I think), 4 stroking. This also leans out the my 1/2 to 3/4 throttle to much, I think.

Two - lower the needle to position 1 and put a shim under it to get a 1.5 position, this might split the bottom end 4 stroking and lean 1/2 throttle position.

Three - Measure my needle, see what I have and sort through the pile of needles I now have, looking for one that has a larger OD at the top.

I have 10 new sparkplugs to perform plug chops and see what I get. Would like to see a few miles at 1/4 throttle and 1/2 throttle, was out yesterday trying to scout where I can pull off and remove plug.

So does this sound reasonable? Anything I'm missing?

Not quite ready for Dyno runs or plug chops just yet.

The 24 cog should be ok on a Pinasco. If you have a 36 tooth in there it will definitely be ok.

Set the airscrew when at 1/8 throttle or at least very fast idle. This gives better results.

Keep the main jet out until everything under 2/3 throttle is absolutely perfect. And WOT still splutters really bad. This is the quickest, easiest and safest way to jet a needle carb.

I use 24/63 and a 36T 4th in my Pinasco 225 and it's great for most situations, although it was a bit over geared with a passenger and luggage on Spanish motorways!! You will be fine with your 24/65 + 36T 4th.

My goal is to get my local county road speed limit of 60mph away from the 6800-7000 rpm rev limit she seems to have. Running 60 mph or 97 kph, she is running close to 6000 rpm. I do have a 36 tooth 4th, if Stella is over geared it's nothing irreversible. Also a good excuse to get a TSR Vortex or BGM touring both have 15% + more torque in that rpm range over the SIP road xl I have now.

I have been setting the idle to 2000 rpm with the set screw. On the pilot jet, once I try a few smaller ones, isn't there going to be a point when the idle doesn't want to come back down because of being lean? Never tried going as lean as possible on purpose, always aimed for a turn or two out of adjustment. I was experimenting last night currently anything less than one turn out idle is rough, so rich with this being an air screw. Never did lean out and slow down even with the screw ready to fall out in my hand.

Last edited by Christopher_55934 on Wed Oct 14, 2020 8:16 am; edited 1 time in total

Sounds like you have achieved lean pilot. Can't turn out more than 1 turn is where it needs to be to get the first part done. Obviously.......don't ride it far or hard or it WILL blow up.

With the pilot jet ultra weak and the main jet missing all focus now on the atomiser diameter.

Increase the size of the atomiser until just under 1/4 throttle splutters bad. Not coughing but full on machine gun splutter. Where you know its nothing else but way too rich. Then reduce the size of the atomiser one at a time, until the splutter has gone and it runs nice....at 1/4 throttle. All other throttle positions will still be bad but 1/4 will be good. Once this is done, onto the next step.

Do you think it would be worth trying different jet needle positions? I know I can move to position 1 to lean out and get rid of some 1/8 throttle 4 stroking, 2 starts to 4 stroke a little at 1/8 throttle, 3 really 4 strokes @ 1/8 throttle, wondering if I move to position 4 or 5 if the 1/4 throttle would get rich.

Was trying not to get into every detail. When the atomiser is set at 1/4, the needle should be on clip 3 for a 5 clip needle. Can't set the length without setting the atomiser first.

First of all I didn't get a test ride after so who knows how Stella runs. I do know she runs i started her up to get a heat cycle in. Other priorities like fixing my wife's car, needed a new starter.

Put , the DRT 24 tooth clutch cog in today, no issues fit right in.

Pulled the head and looked to see how she was doing, took a few pictures.

Took a few pictures of the piston top also, I remember something about piston wash have to look up and see what I can find.

Took a look at the exhaust port again while, not going any wider than 60%. Not much room between the exhaust side cylinder studs.

Opened the boost port up a bit to match the cylinder. Wondering if anything will show up on dyno or jetting?

Looking at the side transfer ports, I can see where they are being fed through the cylinder like a stock cylinder. Will think about opening up the case later and adding case ports. How much of a difference will that actually make?

Pictures to follow tablet not letting me add them for some reason.


Bottom of cylinder head.

Picture of piston top, about 20 miles on the current jetting.

Measured stud length sticking out before marking which end is up.

Gasket on top of case just a bit of material to remove.

Gasket on top of cylinder, for comparison.

Green sharpie showing what needs to come off.

Piston top



No more green sharpie

Rotary pad looks to be in great shape.

Rotary pad looks to be in great shape.

Rotary pad looks to be in great shape.

Rotary pad looks to be in great shape.

There must be a book or source with this information or these guys copied each other.

http://www.mmec.net/diagnostic.htm

https://mcbperformance.com/p-25418-piston-failures-causes.html

https://www.google.com/url?q=https://www.thetuningworks.co.uk/assets/Piston%2520Diagnosis.pdf&sa=U&ved=2ahUKEwjpmOTRu8DsAhVabs0KHZQ4DB4QFjASegQIAhAB&usg=AOvVaw3Ml80QjjIB2dLLBID41kaL

Jets showed up today, tomorrow high of 35°F or about 2°C and three inches of snow.

Pinasco A3611 or part number 25243611, I've been looking for a built in head squish band measurement and ran across a post saying it is 1.3mm. With my 60mm crankshaft I have a PBT of 0.38mm, so my squish would be 1.68mm. Looks like I have a 2.12mm squish at the moment with a Genoa 810 head. I would like to find the squish band of the A3610 head part number 25243610. I really wish these companies would publish specs on their parts, with only two motors I have seen, there is quite a bit of variation. Pinasco for instance advertises a 11:1 compression ratio and basically a 1.5hp increase with this head. How can they publish a CR of 11:1 and not even know your PBT or port height measurements?

Squish is listed in this post.

hot or not? Joining the ranks of the data geeks! (Page 2)

This is the reply I received from Pinasco. I asked about the two versions of heads and what the squish of each is.

Dear Customer,

The squish must be between 1.7 and 1.9mm, if you want to fit a central spark plug head you should purchase the item 25243611.

Best regards,

Pinasco Staff

Todays notes or miscellaneous ramblings.

Got to 42*F or about 5.5*C, today and got a short test ride about 20 miles, This was my first ride with the DRT 24 tooth clutch cog, has a shorter fourth. My test hill, you all have that one hill you want to be going faster at the top, I know you do. I climbed it with no issues, 24 tooth cog isn't over geared in my case. I was doing 62 mph at the top, so that's a plus. Most of my riding at 60 mph is half throttle and 5800 rpm.

Using a N-6 (2.580mm) needle jet down from a N-9 (2.595mm).

With a N-9 needle jet, my jet needle was in position 2, I was thinking position 1.5 would lean it out about right. Position 1 was to lean with the N-9.

With the one step smaller pilot jet 27.5 to 25 and N-6 needle jet, there is a lean transition spot say around 1/8 before a 1/4 that I could feel and hear lean and had a lean surge. My AFR meter said 18.8 and lean. Pulled into a lot and moved the needle clip to position 3 or the middle. This made the lean 1/8 or so transition better. Still in the 14's at one spot but then moves to 12.8 or richer after 1/4 throttle. Idle was a little lean around a 14.3 also, but to be expected with the smaller pilot. I need to get some better notes, but this did move me closer to center for needle position as expected.

Observations during normal riding at highway speeds, at half throttle, about 5800 rpm or 60 mph. I'm a bit richer then position 2 with the N-9. My AFR meter says I'm a bit richer and so does my head temperature, as it never climbed above 187*F and my AFR meter said I was running around 12.6. A 2.5 needle position might dial me in a bit closer, for the rest of the range with position 3. A little rich isn't bad since the cylinder only has about 300 miles on it now. I do have needle shims to try at some point.

I also have a N-4 needle jet I could try which would lean me out a bit more at 1/8 throttle transition but would get me closer in the half throttle range.

Still thinking I should try a EGT meter and see where I'm running, no hurry as its a bit chilly here and riding season is coming to a close.

Put the main jet back in and got a few graphs to have for notes and history. Doesn't look like I messed anything up while I had Stella apart, that is always good to know. There is a little bit more power in the 4500 and 5000 rpm range, not sure why. Maybe opening up or matching of the boost port? I did make the gear changes for GSF dyno. Thinking of lowering the squish next by taking a little off the head, to see if there's a change.


Doesn't look like I messed anything up while I had Stella apart, that is always good to know. There is a little bit more power in the 4500 and 5000 rpm range, not sure why. Maybe opening up of the boost port? I did make the gear gear changes for GSF dyno.

Spent some time reducing squish today, working towards Pinasco recommendations. Checked it above both sides of the gudgeon pin and have about a 1.60mm. A little less than 1.7mm, not as big as the optimistically small 2.12 mm I was getting. Didn't spend a lot of time trying to get a perfect measurement as I'm no where near to small for clearance issues.

The reduced squish doesn't appear to have helped peak power. It does seem to have moved my peak a few hundred RPM right. Looking at a few other graphs it appears, as performance has improved the power has moved to the right on average.

I also wrapped my KOSO or SIP 2.0 cht sensor in shrink tubing. I read that it raised a few peoples temperatures without cooling air blowing on it. I can say my temps actually got to 278*F at half throttle or just a little less cruising at 60 mph after a 6 mile ride. Around town riding I was around 200*F. My temps are up about 50 degrees, reduced squish or reduced air flow?

I have an EGT meter on its way, well see what I get for exhaust temps.

New plug about 3 miles at half throttle or a little less, saw temps around 275*F.

Went for a 36 mile ride today on some faster roads. Maintained 60 to 65 MPH GPS verified. Sip speedometer is about 1 mph fast, have to figure out how to adjust it a bit. Have to pull out the instructions.

Lowered the needle to 2.5 from 3.0. Position 2.5 for someone reading this and going what is position 2.5? I put a Mikuni needle spacer under a clip in position two. The spacers give you half positions. Highest temperature I saw was 303*F, that was a slow climb to get there. As soon as I let off the throttle and slowed a bit to 55mph temps dropped to 270 - 250 ish. Anytime I gave a little more throttle default was a little richer on my meter, good for keeping a cylinder in one piece.

Need to dial in main jet now, I don't like running WOT at 7000 rpm and don't keep it there long enough to check temps. Hopefully EGT which is said to react faster will help with that. Otherwise I need to find a longer hill I can use in fourth to keep rpm down. Currently the one maybe 1/4 mile hill I use, Stella wasn't getting hot. That's about 6 miles into my ride at half throttle so she should be warm.

Last edited by Christopher_55934 on Thu Nov 05, 2020 7:47 am; edited 1 time in total

Good stuff! Whats your RPMs at that cruising speed?

5800 to 6000 at ~ 60 MPH

Reviewing this thread and I have to agree after today's ride at 60 - 65 mph.

outstanding temps look good

Son of a ......

I put another 35 miles on yesterday, did a plug chop at 3/4 throttle after about 9 miles at speeds of 60-70 mph. Spark plug was a nice dark brown, temps never got over 300*f. I was feeling good my jetting was getting close. Gas mileage was over 35 mpg because I didn't even put a full gallon in.

Stopped at a gas station put in some fresh gas and oil. Riding along about 5 miles later, something doesn't feel right, I look down see a temperature of 340 ish, I pulled in the clutch, she dies, pulled off the road. Temps climbed to 391*f sitting when I looked at my max temperature. Never fully seized but I could tell compression wasn't correct and she wouldn't start. Wife picked me up and I trailered her home.

Pulled the cylinder head and didn't see a hole, that's good. I also didn't see any carbon on top of the piston it is clean WTF? Cylinder sidewall looked fine also, pulled the cylinder off completely to get a look at the piston and it has donated some material to the sidewall not bad. The piston rings are stuck in place by the exhaust. I'll post some pictures later. I'm thinking I got a bit of dirt blocking my main jet or bad gas. I realized today I never put a fuel filter in. Son of a .....

If I can't clean it up, going to try a bit later and see what I get. Assuming I need a new piston and rings, do I get another Pinasco? Should I get a Grand sport substitute? I didn't see one on there site. Maybe a Malossi piston?

https://www.sip-scootershop.com/en/product/piston-pinasco-b-215-cc_55043000


Would one of these work?
https://www.grand-sport.de/Piston-kit-GRAND-SPORT-MALOSSI-210-aluminum-685mm-and-6900mm

The 69mm version will probably be OK, although the L shaped ports could be a problem. On my friend's old Pinasco 213/215, I used the 69mm Polini version and it was OK with the O-Tuning, although it was always running hot and pinging due to the shitty head. We eventually changed the kit for the Malossi Sport...

I think the two 69mm pistons are the same, with the Malossi version having the extra small port above the boost port...

Pinasco 213/215 -> Now Malossi 221

Dammit. These things really hurt when they happen! Maybe idle jet? Since it pinged the temps when you were driving slower and shut down.

Pictures before and after of the piston, it seems to have cleaned up ok. Cleaned out the grooves and the ring slips through the slot fine. The black smudge on the cylinder wall not so much. Tried a tooth brush dipped in muratic acid. I know the muratic acid is reacting with the aluminum because it smokes on the non coated surfaces.

Unfortunate. Don't over clean it. Put it back together and run to destruction. Could still be 10,000 miles in it.
Leave the main jet out when it's next running. Start jetting from the beginning. 3/4 is the hardest position to set. Now you know that needle is not the one. Always learning.

Christopher.
Uh boy.
I swear - its like you need to plan for trashing a set of rings just to get jetted in - then put a new set in for break in after you get jetting close (after one removes the aluminum they have smeared everywhere).

Clean up looks top notch.
Seems like very small damage in my eye.
As long as that piston groove isn't trapping the rings you should be in good shape.

Frustrating -but looks like you have it under control.

Question - what do you think caused the temp spike? didn't quite follow.
-CM

Cause was the carburetor top wasn't rotated far enough away from the frame. I now have a nice gouge in the paint and the corner of the carburetor top. Finally got knocked loose after 150 miles and cause a small air leak.

Stella's running again, let her idle on the stand for 15 minutes and nothing blew up.