High comp piston, what am I in for?

[CodyRosa]

Hey guys, I purchased a 10.25:1 Wiseco Piston today for a 84 200M. Basically I'm just wondering will this need to be rejetted? I'm assuming yes, if so by how much? Its all stock jetting, stock everything right now. How much more "power" will I gain? Will it be a night and day difference? Will my machine be faster, slower than the stock compression?

And for breaking this machine in what are some tips? How do you break it in? Is it different with a higher comp piston?

If anybody knows of any shops that do bore work around the Minneapolis area please let me know! I'm trying to find someone but not to sure what to type in. Apparently small motor machine shops doesn't work.. =/

Thanks everyone!

[hatc200x1]

If everything else is stock it probably wont need to be jetted much, if at all. just check the plug. Cant tell you on how much more "power". Wont be much faster unless you change gearing but you will get to your top speed faster.
For break in and sence its higher compression you will need to run higher quality gas, premium should work.
Run it for like hour or 2 at varying rpms and dont hit wide open for like 20-30 mins of run time, and when you finally do, only do for a very short time.

When I rebuilt my 110 I even ran mixed gas in it for the first tank and had no problems.

For the machine shop you might have to ship but look up Northern Crankshaft, they do excellent work. Very nice guy, have talked to him personally and he teaches you a lot of stuff. He is actually recomended by basically every snowmobiler on the planet, ive been to there shop and there busy all the time! He gets soo much business. He gets motors sent to him from all around the country, especially the heavy snowmobiling states.

[CodyRosa]

yea I'm ok with more acceleration haha, thats actually what i wanted. Will i have more "motor" to pull a higher counter sprocket gear? I will for surely look up that business! Thanks for that. Whats his turn around time? Whats he normally charge?

Thanks again!

[hatc200x1]

You might have enough "motor" to go a little higher gearing but it will sacrifice what ever acceleration that you would have gained if you would have left it at stock. Honestly id leave it at the stock gearing so you can have some fun. His turn around time is pretty decent in the summer but torwards winter and during winter he is swamped. No clue on the charge, you would have to give him a call, I had him do some work on my 200x topend and he did it for free. He also did work on my brothers snowmobile motor my brother screwed the cases up on from pounding a screw driver into them to get them apart, fixed them like new again. He has worked on many popular snowmobile race teams to build them hi-performance engines.

Heres the website for information.

http://www.northerncrankshaft.com/

[CodyRosa]

well basically i had a 13 tooth up front and liked it but loved stock 11 tooth for that acceleration and the ability to hill climb. I went to a 13 with 22 inch tires and there wasn't enough motor there to pull it.. i topped out at probably 52.. it was no were near high revs either.. to weak =( Yea maybe i'll give him a call tomorrow. I was already quoted 75 from a place nearby but it was only that expensive because they ship it out somewhere so there the middle man. That's why i'd like a place nearby that my dad can drop it off. Thanks for the link.

[Jason125m]

You won't have to rejet, having a higher compression piston does not change how fast air gets in, or how fast it gets out, therefore you do not need more fuel.

General rule is , if the mod makes the engine breath better, it needs fuel, which means rejetting.