yd100 to p85

[Andrew1234]

I have a yd100 with a 12mm crank and want to convert it into a p85 do I have to measure anything else to make it work or should it just bolt on?

 

[Andrew1234]

I have a yd100 with a 12mm crank and want to convert it into a p85 do I have to measure anything else to make it work or should it just bolt on?

Because I heard something about stroke being an issue

 

[Wyvern]

Because I heard something about stroke being an issue

I don't know the specifics with the swap, but you would definitely check squish gap and port to piston alignment.

Something with only certain length con-rods work.

 

[Hunter]

https://motoredbikes.com/threads/yd100-to-phantom-85-ms460-conversion.64885/ maybe this will help

 

[Andrew1234]

https://motoredbikes.com/threads/yd100-to-phantom-85-ms460-conversion.64885/ maybe this will help

I read it and it helped a little bit thank you. I just need to know how I could measure the stroke and what stroke size I need to run a p85 kit.

 

[ImpulseRocket]

It was designed for a 40mm stroke, so if it comes with anything less your squish gap will get larger, not smaller. Mechanical obstruction is not likely. The Phantom also runs with 2 base gaskets out of the box. I have a 40mm stroke, I removed 1 base gasket, removed material from the deck and jug flange, and the meteor piston is taller than the stock one. My squish gap after all of that is .9mm.

You should be A-ok.

 

[Andrew1234]

It was designed for a 40mm stroke, so if it comes with anything less your squish gap will get larger, not smaller. Mechanical obstruction is not likely. The Phantom also runs with 2 base gaskets out of the box. I have a 40mm stroke, I removed 1 base gasket, removed material from the deck and jug flange, and the meteor piston is taller than the stock one. My squish gap after all of that is .9mm.

You should be A-ok.

Alright, thank you and I will give updates when I buy the piston and cylinder and do you know where I can get a full gasket set for the p85?

 

[ImpulseRocket]

Alright, thank you and I will give updates when I buy the piston and cylinder and do you know where I can get a full gasket set for the p85?

The exhaust and intake gaskets are on Bicycle-engines. Base gasket is standard yd100. The intake gasket is also generic. Just the round hole version with 40mm spacing.

 

[GW's Motorized]

Or @mark20 can make you quality gaskets.

 

[ImpulseRocket]

A possible alternative for the exhaust gasket is a GY6 exhaust gasket. The bolt holes may need a little elongating, but it looks promising. This was seen on a recent Avenger 85 thread, which has a nearly identical exhaust port and flange size/layout. The opening is 1mm smaller in diameter than the ports (27mm vs 28mm https://www.amazon.com/Amavoler-Exh...19&sprefix=gy6+exhuast+gasket,aps,172&sr=8-43