Kymco SC10AS 100cc and beyond:

[oldgeek]

I have not had much time to work on this, but I did get this done.
Boost port opened up. There is not much left for the cylinder base to seal to the cases around the transfers. There is actually even less than what shows because the cylinder does not match up very well.

Intake path opened up. Still just a bit left to be done here. Next up is trimming the cylinder skirt a bit.

[oldgeek]

Epoxy time. I cut a plug out of aluminum to fill the oil pump area a bit. The balance of fill is epoxy.

[oldgeek]

TPR 86cc Motor build:
On a side note, I am again working on adapting the TPR 86cc horizontal minarelli LC cylinder to Kymco vertical cases. A few years back I had it mostly worked out except for the crankshaft. I was trying to make the Minarelli TP86 crank which is a 44mm stroke work in the Kymco cases by fitting the crank with a longer rod then doing some other mods so crank seals would work. However I gave up along the way because it was not working out.
Then the other day I realized there is a 44 stroke aftermarket crank for use on some of the aftermarket Kymco cylinders. I happened to have one of the 44 stroke Kymco cranks on the shelf and started measuring and fitting it up. All I need to do is find a 90mm con rod to replace the 80mm con rod that is on the 44 crank and I am good, I think!LOL

Currently looking for a PRO-X 03.1005 rod, it should be the ticket. Fee bay has one for$100+ shipping from Germany but I aint paying that.
The only drawback I see is that it will be a "stockish" crank with a 16mm big end pin on a high rev cylinder.

[190mech]

Is there an 18mm pin crank that would work? Lots of rod options in 18..

[oldgeek]

Sept 14, 2024 4:17:18 GMT -5 190mech said:

Is there an 18mm pin crank that would work? Lots of rod options in 18..

I have not seen one. I actually have two of the 44mm stroke cranks, both have 16mm pins, one is rather cheap with plastic inserts and one is a nicer full circle type. I think a 18mm pin would end up very close to the edge of the crank wheel.

I already have a Pro-X rod with a 18mm big end pin I was going to use with the Mina crank.

[190mech]

I spent a bit looking for a stepped crank pin (16-18-16) with no luck..Dont know how much it would cost to get one ground, know it has been done in the Vespa builds before..

[oldgeek]

Sept 15, 2024 4:17:00 GMT -5 190mech said:

I spent a bit looking for a stepped crank pin (16-18-16) with no luck..Dont know how much it would cost to get one ground, know it has been done in the Vespa builds before..

That is an interesting approach, I think pitobread machined the holes in the crank wheels bigger or moved them to another location once. I think any machine work will cost as much as the rod I am looking for.
I'll find one of those rods cheaper eventually.

EDIT: Ordered one from GreenlandMX for about $75 shipped. Who knows when it will get here LOL!

[190mech]

My next suggestion was going to be to cut 2 rods the proper splice overall length and weld them back together!

[Timmer]

Who would’ve imagined that ‘GreenlandMX, is actually based in Spain…? With a name like that, i’d have guessed Greenland. But i don’t think it’ll take that long to get to the US tbh.

[oldgeek]

Sept 18, 2024 3:56:31 GMT -5 190mech said:

My next suggestion was going to be to cut 2 rods the proper splice overall length and weld them back together!

I'll send that job up to you

Sept 19, 2024 15:26:53 GMT -5 Timmer said:

Who would’ve imagined that ‘GreenlandMX, is actually based in Spain…? With a name like that, i’d have guessed Greenland. But i don’t think it’ll take that long to get to the US tbh.

They said 5-7 days before they get it, so who knows when I will get them.Lol

[oldgeek]

Spent the day rounding up gearbox parts and replacing all bearings and seals in the gearbox and checking to see if it meshed ok. I will be taking it back apart to install the crank and cylinder. I dont like trying to do gearbox stuff on a built motor, easier to do before hand.

I had to order a set of 150mm cylinder studs from Scootertuning, 2 of the four studs in the Vastro cylinder kit were crooked.

The Vastro cylinder head is of questionable quality. The holes in the head for the cylinder studs were drilled halfway through from each side and they did not line up very well where they met in the middle. I ran a 6.5mm drill through each hole to open them up a bit.

I also tried to install the water fittings in the head for a test fit, but they would only screw in about one and a half turns. I think they were the correct size before they anodized the head, I guess I will have to get a tap that is the right size and run it through to open them up. When they say "kit" they really mean it!

I got an email from GreenlandMX, they said the rod for the TPR86 motor I am working on should arrive here 9/26 so that's not too bad.

[oldgeek]

Cut the case a bit so the heavy duty starter would fit.


The 150mm studs I purchased from scootertuning arrived. I gave them a test fit, they are straight but the threads are undersized. The nuts wobble when you thread them on. I tried several nuts from other kits, they all fit loosely.
I bought 2 sets @ 14.99ea = $29.98 + $13.60 shipping = $43.58 shot to hell. Its so frustrating, are my expectations too high?

[190mech]

6, 7, or 8mm stud?

[oldgeek]

Sept 22, 2024 4:21:53 GMT -5 190mech said:

6, 7, or 8mm stud?

M6x1 I found some in the amazon, US made carbon steel. These should be good, right? studs

[oldgeek]

Sept 13, 2024 19:44:16 GMT -5 oldgeek said:

On a side note, I am again working on adapting the TP86cc horizontal minarelli LC cylinder to Kymco vertical cases. A few years back I had it mostly worked out except for the crankshaft. I was trying to make the Minarelli TP86 crank which is a 44mm stroke work in the Kymco cases by fitting the crank with a longer rod then doing some other mods so crank seals would work. However I gave up along the way because it was not working out.
Then the other day I realized there is a 44 stroke aftermarket crank for use on some of the aftermarket Kymco cylinders. I happened to have one of the 44 stroke Kymco cranks on the shelf and started measuring and fitting it up. All I need to do is find a 90mm con rod to replace the 80mm con rod that is on the 44 crank and I am good, I think!LOL

Currently looking for a PRO-X 03.1005 rod, it should be the ticket. Fee bay has one for$100+ shipping from Germany but I aint paying that.
The only drawback I see is that it will be a "stockish" crank with a 16mm big end pin on a high rev cylinder.

TPR 86cc Motor build:
The 90mm con rod I ordered arrived today, the suspense was killing me so I got started switching the rod out.

I pulled the cheaper of the two 44mm stroke Kymco cranks I have apart. I cannot believe how hard it was to press apart. I removed the plastic stuffer inserts because one seemed loose anyway. The big end pin that came with the new rod was quite a bit too long so I decided to use the original pin that was in the crank. The 90mm rod big end is wider than the stock rod by a few mm. That works to my advantage because I have a spacer between the case halves to allow the TPR86 cylinder to fit the Kymco cases.


The stock pin is just a little short, but I am not going to worry about it. I could always TIG the pin in place if I feel the need. I cut a bunch of round shims to hold the pin centered while I pressed it back together.I have not trued it yet but I did eyeball it close enough to check the setup.


I am excited because this should work out good! I have 2 base gaskets in to get it where it is.




The crank will not turn with the cases bolted together as it sits but I should be able to work tha out by pinching the crank together a little and make the case spacer just a little thicker. There is still a lot to work out, the exhaust will need to be fabbed up. I am in the early stages of getting the dimensions of the MHR big bore exhaust into a CAD program so I can hopefully build it to fit the scooter this motor ends up in. So once again I have too many irons in the fire so this project will take a while to complete.