Honda 200s jetting with 10.25:1 piston

[PAPA250r]

Would like to know if jetting is required with a 10.25:1 piston stock exhaust. It runs great but i am rebuilding the carb and jets are not marked so would need to know what size jets to get i have the stock specks from the manual . Thanks

[barnett468]

Would like to know if jetting is required with a 10.25:1 piston stock exhaust. It runs great but i am rebuilding the carb and jets are not marked so would need to know what size jets to get i have the stock specks from the manual . Thanks

Hello


Did you bore it out to do this?

If so, how much over stock is it?


Either way I would go up 2 sizes from stock on the main and 1 on the pilot. A few reasons are that a newly bored cylinder runs a little hotter than one that is the same size bore but has been broken in. A cylinder that has been farther than a comparable broken in one will run hotter still. A cylinder that has been freshly bored with a high compression piston will run the hottest. It will run slightly cooler with more fuel.


Listen carefully for a slight "pinging" sound under acceleration. If you hear one you may need to reduce ignition timing by around 4 degrees if possible and/or run race gas. Leaving the ignition timing as is and running race gas to cure detonation will provide the most poser but cost the most.

[PAPA250r]

I believe it was bored 30 over from the previous engine owner it is well broken in lol been running it a few years but i never had the carb apart until now

I def do not hear any pinging i am familior with the sound its pretty quiet with the stock exhaist

[barnett468]

Hello


I would also install a new spark plug.

Clean air filter.

Make sure air box lid is on.

Break in properly, don't get too anxious.

Check spark plug color after 1 hour of time on it.

Lite gray = lean

Lite tan = good

Dark tan = slightly rich

Dry black = too rich

Moist after sitting 5 minutes irregardless of color = burning oil

[barnett468]

Hello


Post correction The word "poser" in post 2 should be "power".

I have no edit button.

[barnett468]

I believe it was bored 30 over from the previous engine owner it is well broken in lol been running it a few years but i never had the carb apart until now

I def do not hear any pinging i am familior with the sound its pretty quiet with the stock exhaist

Hello


So the 10.25:1 piston has been in there a long time?

You did not just put a 10.25:1 piston in the existing .030 bore?

If this is the case and you hsave been riding it this way for a longt time and it runs fine then why are you now asking about the jetting?

[barnett468]

Hello

Post correction, "hsave" should be "have" and "longt" should be "long" in the post above.

[barnett468]

I have no edit button.

[PAPA250r]

Rebuilding the carb after it started to recently leak and run like crap amd the jets arent marked.

I refuse to put another POS moose rebuild kit in it so i buying OEM parts to rebuild it

[Scootertrash]

Find your manual here, then download it to your computer. You'll always have one then.

http://www.oscarmayer.net/atc/manuals/