questions about a 81 atc200

[spepple]

So I took my jug and head to the local shop, head needs new intake valve. Jug needs bored to 65.5. What I'm thinking is wiseco 10.25-1 compression piston kit. Anyone think otherwise? So I can't access the 3ww shop or discussion yet due to being such a new member. I'm looking for both left and right brake levers with mount. Also on the 81 does the headlight have the switch mounted on it?

thanks everyone for your input, it is greatly appreciated.

[shortline10]

Headlight switch is mounted on top of the light for the 1981 model .
The wiseco is a ok choice but (rings suck IMO) if you plan on riding a lot go with a std 9.2:1 200x compression piston at 65.50 .
dratv.com should have all the parts you need .
Here is the piston kit .
http://www.dratv.com/pistonkit1.html

[spepple]

Headlight switch is mounted on top of the light for the 1981 model .
The wiseco is a ok choice but (rings suck IMO) if you plan on riding a lot go with a std 9.2:1 200x compression piston at 65.50 .
dratv.com should have all the parts you need .
Here is the piston kit .
http://www.dratv.com/pistonkit1.html

anyone else got an opinion on the 9.2:1 compression piston. thanks shortline, just trying to get more responses.

[barnett468]

what is your goal?

is your cam stock?

The piston listed by shortline is a cast [not forged] orig style piston that is made in Japan and is good quality. Shindy also makes some other engine parts at fair prices, see them in the link below.

http://www.shindypro.com/

[DohcBikes]

I like the 200x piston personally, combined with an xr200 cam, which is available new from servicehonda, and an xr200 carb. Makes good reliable power.

[spepple]

i wasn't planning on changing the cam or carb, at this time anyways.

[DohcBikes]

Then I would not use the 10:25 piston. That's just my personal experience. The X piston will work fine with a stock cam and carb.

[barnett468]

i wasn't planning on changing the cam or carb, at this time anyways.

I would run the stock piston from Honda or Shindy then. Boring it out .020” will get you around .13 more compression.

You will get around 5% more hp and tq with the 10.25 but it might be on the verge of detonation even with 91 octane gas but not with E85. It will also run slightly hotter with the higher compression.


Supposedly new orig Honda piston $39.00

http://www.ebay.com/itm/NOS-Honda-05...8#ht_187wt_938


New old stock factory Honda parts.

13103-958-670 piston $60.00

No rings

http://www.partzilla.com/parts/detai...3-958-670.html


piston 13103-958-670 $95.00

rings 13013-958-671 or 672 $67.00

http://www.cmsnl.com/honda-atc200-19...3.html#results


try xtremeusa.com for orig parts also.

[spepple]

The jug I have has to be bored .50 over

[DohcBikes]

.50mm over is ~ .020", as Barnett stated. Also as he states, the 10:25 piston is going to run hotter, especially with lengthy riding, and you will get nominal gains without changing cams.

Not sure what your engine runs for HP, but assuming its around 12, you would gain about .6 HP.

So you would have a 12.6 HP motor that is running hotter under any condition.

[spepple]

My bad I misread it l