CPI Oliver City 50cc to 103cc

[90GTVert]

It's a shame the Vento site doesn't take orders now. I know that other gear would be cheap.

EDIT : I checked their site and they no longer have any US section. I went to another and that gear is $42. I thought they were supposed to be out of business completely?

PFS has a couple, not sure that either is right...

www.partsforscooters.com/Vehicle-Type/50cc-2-stroke-1E40QMB-Long-Transmission-Parts

[2strokd]

What was figured wrong John?
What count idler gear do you need?

[190mech]

I was sleeping when I did my math!Needed more duration,not less on the transfers,this must be a very mild cylinder.Gonna try a .090" spacer and see what that gives.

Dont know the tooth count on the idler gear,confused about the ratios listed here and there on the web...

[2strokd]

I remember Brent saying allot of the bigger 50mm+ jugs are ported close to or like a stocker, or mild Sport kit. At least it iron anyway . Im sure you will get it dialed in sweet with time. Wish i could come over and help!
Then play !!! Ive got a few sets of gears in cases. I only checked the "swamp" gears for ya. Lemmie see what i have

[190mech]

Fabed a .090" spacer,with 1 gasket(.037"),I got 134 transfer and 184 exhaust,think I'll make one from .062" or maybe .050" with 2 gaskets and see what that gives me..

[190mech]

Had a little time after work tonight to make a .050" cyl base spacer,with a .015" gasket on the top side and the stock gasket below,my transfer timing is now 130 degrees(right where I wanted it!),raised and widened the exhaust port to get 184 degrees,hope to check head squish and finish up the port cleanup after work tomorrow,will post some pics then..

[90GTVert]

Gettin' there. I'm interested to see just what you've done with the ports.

[190mech]

Here are some pics of the 103 project,cyl to case fit;

BDC view of case to cyl fit;


Piston at TDC;

Squish check with head gasket;

Ex port after cutting;

View of intake side of cyl skirt after cutting;

Maybe tomorrow it will be bolted together....

[90GTVert]

Everything looks great. Thanks for all the pics!

[2strokd]

It does look very well! I bet it will flow great :thumb: !
Looking forward!
Any piston work? Are you going to do some head work also?

[190mech]

Got the cases together today,what a bear!Fabed a 'puller' to install the crank without hammering(affects balance) or excessive heat(dont wanna melt that epoxy!),verrry snug fit..Made up a reed spacer to get it away from the boost port,used .250" aluminum;

Did a pressure leak test,had a big one at the carb/reed adapter,
cut a gasket and it still leaked!This seems to be a common problem;

Cleaned it up and put a coat of BBQ black on for heat dissipation;

Still need to come up with the tranny gear and build a new pipe yet..
I did no piston or head mods,kept the squish at 2mm,wanna see how she 'acts'..

[90GTVert]

You've probably got it fixed already, but I use permatex ultra black on the reed gaskets. I think the last time I swapped reeds on T2 was 4-5,000 miles before the latest tear down and it was holding up well. Threebond works too, but wow is it overkill.

I was thinking of BBQ blackin' my cases since Robert suggested painting. Kinda gives me a sneak preview! ;D

If you can't find the gears by the time the pipe's done, you should try it with what you have. I bet it would be amazing fun around town. Just get someone to take pics or vids of you doing power wheelies for us! ;D :riding:

[2strokd]

Looks great! Darn intake is a common place for sure! Great thing, that leak tester can be . Good idea giving it a go with the 2mm of squish first. You have a tach right?

[2strokd]

After looking more, in the last pic of your cylinder the top of the ex port looks pretty flat and straight.
Is it just the pic? Looks like a ring snagger but pics can thro so much off.

[190mech]

Ex port is verry rounded at top and bottom,gave it a good chamfer like Bell's book says..
I have no tach but theres a 'cheapy' on ebay I'm looking at..