84 200x valve replacement and 12:1 piston

[KingNothing]

Hey my buddy has an 84 200x... the thing has seen better days and smokes like a train. He brought it up tonight and we pulled the engine and checked it out. 65mm bore (factory)....


So we.... called up dennis kirk and ordered

Valves
Valve seals
Complete gasket set
New Clutch
12:1 weisco Piston

Easy to do when your spending someone elses cabbage.


Does anyone know the stock CAM lift on a 200x?

When replacing the old valves do you just switch them out or do you use valve grinding compound????? I am new to 4 stroke rebuilds (in atv's).

How noticeable will the 12:1 piston be?

[Erics350x]

you wont notice any difference with the 12:1 other than its harder to kick and cost you a crap load in race gas unless you upgrade the cam, carb, exhaust, and air filter. Google search valve lapping. And checkout powroll.com

[KingNothing]

my friend was told that it had a cam in it. But I see no numbers or markings to lead me to believe otherwise. Would like to know the specs on a stock one to check it out.

[AutoXer]

post a pic of it ..... cancel the 12:1 and get the 10.25:1

[lndy650]

you will have to at least lapp the valves if they are really wore you should have someone do a 3 angle job on them... the 12:1 is great as long as you dont mind running race gas and it does make a fair difference in power. the best is to have an aftermarket exhaust and porting to go with it. the 200 heads are really easy to port

[Erics350x]

you will have to at least lapp the valves if they are really wore you should have someone do a 3 angle job on them... the 12:1 is great as long as you dont mind running race gas and it does make a fair difference in power. the best is to have an aftermarket exhaust and porting to go with it. the 200 heads are really easy to port

Wrong! Raising the compression alone wont help a dang thing. It will put more stress on those worn out kicker gears and cost you a fortune in fuel and head gaskets. I made the mistake of running the 12:1 in mine, wish i never would have.

[lndy650]

so because you put a high compression piston in a wore out engine and probly ran shitty gas you think high compression dosent raise power output???? ive had countless 200 engines with 12:1 pistons and they ran great with more power

[Macs]

With just raised compression alone you will not see much improvement. If you let the engine breath better you will see vast improvements with that piston. If you are unwilling to do other improvements, it is just a waste of money due to purchasing race gas and higher stress on your engine.

You cant just upgrade one thing on a system and expect big gains because the rest will hold it back. just my .02

[lndy650]

like i posted earlier "the best is to have an aftermarket exhaust and porting to go with it. the 200 heads are really easy to port"

[Macs]

like i posted earlier "the best is to have an aftermarket exhaust and porting to go with it. the 200 heads are really easy to port"

ummmm???, i think everyone read the first post. But, ok........

[KingNothing]

The trike is only going to be ran a handful of times per year.... the price of race gas is no object..... also he is considering porting the exhaust and adding a pipe. Basically just wanted to know if doing the work and buying a pipe would make a reasonable difference.

[lndy650]

i got a 200 head i just ported it needs valves and seals if your interested... the valves were good but might as well go with new ones

[lndy650]

................................

[oscarmayer]

I don't agree with you on that eric, i noticed a decent difference in power from a stock to a 12:1. it's also way more responsive. stock cam is ok but yea better cam is recommended. better carb (at least jetting) and better exhaust is also recommended, but again a properly jetted 12:1 on a stoick setup will yeild ok benefits. Now I do agree with the statement it's best to upgrade everything else as well. doing so will yelid big gains, but you will get some from a higher performing piston. but again jetting will be required.


valves, use valve lapping compound and lap them in or pay a shop to do a angled valve job (better performance).

[Erics350x]

so because you put a high compression piston in a wore out engine and probly ran shitty gas you think high compression dosent raise power output???? ive had countless 200 engines with 12:1 pistons and they ran great with more power

Not what i said dip trailprotrailprotrailprotrailpro! I dont half ass my stuff. What i was saying is, with the cost of race gas and the added stress on the slipping 1 gen X kicker it doesnt make sence. Unlees you already have other mods or plan to add em.

[Erics350x]

I don't agree with you on that eric, i noticed a decent difference in power from a stock to a 12:1. it's also way more responsive. stock cam is ok but yea better cam is recommended. better carb (at least jetting) and better exhaust is also recommended, but again a properly jetted 12:1 on a stoick setup will yeild ok benefits. Now I do agree with the statement it's best to upgrade everything else as well. doing so will yelid big gains, but you will get some from a higher performing piston. but again jetting will be required.


valves, use valve lapping compound and lap them in or pay a shop to do a angled valve job (better performance).

If you had enough differnce to notice, its because your topend was worn out. And you build was 200E or of the like?