high comp piston for the 200x

[vanaman]

What are the pros and cons of it? Im getting my cylinder bored to 1 over and the shop has an old stock wiesco 12-1 piston for 1 over.

how much do you think this will shorten the life of the motor?

do think it will be much trouble to start? im 6'1" 250 and im only 23.

steve

p.s. the shop also has a nos wiesco standard bore piston for $50

[ATCrider42]

From what i've read about high compression kits is that you CANT just do just piston and rings. You have to worry about valves, exahaust, and fuel. The fuel and air have to be stepped up, so you have to get a less restrictive exhaust, rejet carb, possibly get a better cam(or a "race" cam), and then probably will eventually have to do a complete valve job. I chose not to do it because a lot of people made it seem like it's not that much of an imporvement and you really have to spend a lot of money to not go very far. And also, it seems liek everyone, and i mean everyone, with a high compression 200x breaks their kick starter. Even a lot of folks without high compression kits break their kick starters.

[Dirtcrasher]

12:1 needs race gas and should have an aggressive cam with it.

If this is an 83-85, you better have perfect kickstarter gears or you may be splitting the cases very soon after the mod.

[ametzker]

You won't need to run straight race gas, maybe just a mix to up the octane a little. Motorcycle and car engines are different when you up the compression. I would venture to say you probably could get away with premium pump gas. I have built a few of the smaller SL 100 engine which are nearly identical and ran a 150cc big bore up to 13:1 and it ran fine with no detonation on pump gas. I never broke a kick starter on any engine, just don't keep kicking it like its a two stroke. No need to change anything else. You might find that upping the main jet a couple sizes and turning the fuel screw in a half a turn will make it run a little nicer. Don't be scared and yes you will notice a substantial difference especially right off the bottom. The hi compression gives it a real good kick down low. If you have any questions pm me, These little engines are a kick to build.

[sittinguy]

Go for it, no nreal need to change everything else, unless you want to get the most out of the change. You will feel a big difference.
I built a 350X motor once, I did not get the high compession piston. I did do the cam, modified CDI, heavy valve springs, full performance exhast. My buddy just built his 350X motor with the high comp piston,, thats it, and he blew me away.

Needless to say I redid mine with the piston, bigger carb. and I got him then.

Rejet the carb, maybe a performance exhast, and a 50/50 race gas mix. And you will love it.

[vanaman]

I allready have an exhaust for it, and im working on the carb also.

So i guess ill give it a shot and see how it does.

steve

[trashy250]

i wouldnt... wen i did my 200x motor i bored it,did the high comp piston,cam,and valves n springs...was gona do the carb next but bein as the early xs have problems with there kickstart slipping i had to rip my motor back apart to do the upgrade spring and then noticed the return spring had a little crack in it...trust me u dont want my problems..id do the bore w a stock piston do a mild cam and carb and airbox mods n def exhaust.ull be in better shape

[swifty]

i wouldnt even waste your time You WILL BREAK THE KICK STARTER! its not if its when, i broke 2 within a week then made mine a auto x

[sittinguy]

If you want more power, go for it. YES, you will shorten the life of the motor. If you ride it really hard, it wont take more than a year till you need to rebuild. But if you only ride from time to time you'll be fine for years of fun.

The trick is,,, don't ride it till it blows up, the day you hear a little clunking, loss of power,, anything weird. Shut her down and fix it.

The guys I knew that beefed up thier 200x rode them till they blew, the end...

One of my friends had a 86 200x with a 13-1 piston, big exhast and carb, and he could almost keep up with my 350x up to 50mph. At night About 3 inches of the header was cherry red at top speed runs.

It only lasted 1 year, and blew up. BUT WOW, it was fast.