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Old 03-03-2011, 05:36 PM
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Default 2002 RM 125 Top end questions

     

Hey, I have a 02 rm 125 and I am looking to give her some more kick. I have heard there are many mods that entail some grinding/ machine work to the cylinder and the head. So if I put a Wiesco Pro-lite standard bore in my bike, what should I do, deck the head or the cylinder? How much? .10? Also, could I have my head ported and polished? Will doing this cause me to have to run race gas? Just wondering if anyone has ever done this before, and how much it does to the bike. Thanks,

Curt
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Old 03-03-2011, 06:39 PM
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i havent done it before, but i plan on machining the head about .10 and giving it more dome area (for more rpm) but here is a good thread on it:
http://www.allthingsmoto.com/forums/...ad-read-52002/
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Old 03-03-2011, 07:09 PM
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Quote:
Originally Posted by cbush314 View Post
Hey, I have a 02 rm 125 and I am looking to give her some more kick. I have heard there are many mods that entail some grinding/ machine work to the cylinder and the head. So if I put a Wiesco Pro-lite standard bore in my bike, what should I do, deck the head or the cylinder? How much? .10? Also, could I have my head ported and polished? Will doing this cause me to have to run race gas? Just wondering if anyone has ever done this before, and how much it does to the bike. Thanks,

Curt
Requiring race fuel depends on the amount of compression, so that depends on how much you mill the head. If it where mine first thing I would do is take the cylinder and head to a machine shop and have them clean it up (meaning intake ports and exhaust) possibly mill the head a little.

Then I would pipe it with different reeds and reed block.

How extreme you decide to go is up to you.

Thanks
Scott
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Old 03-04-2011, 08:16 AM
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Before you mess with the cylinder, I recommend you go with an aftermarket pipe and reeds.
I wouldn't mess with the porting myself, if you mess up porting it's a one-way modification. There are plenty of reputable two stroke tuners out there: PC, FMF, Eric Gorr and on and on. Definitely don't do anything that requires race gas, and by working with a tuner they can make sure you won't need it. Porting however is only in the cylinder, not the head. And as is suggested, you can clean up the ports yourself, just don't do anything to change the dimensions of the actual port sizes. Polishing the head won't require race gas.
Something else... you could put a big bore kit in that bike probably, maybe knock it out to 144 or something? Unless you are running nationals it's perfectly legal for local racing.
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Old 03-04-2011, 09:16 AM
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Thanks for all your replies. Ok, so what im looking for its some cheap mods that I will get a noticeable amount of power, while still running premium gas. Even premium + octane booster. Or hell, even a 50-50 premium and race gas. So if I put in a new piston( stock bore Wiesco Prolite), shave .10 off the head, and .10 off the dome, what kind of gas will I be able to run? Thanks
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Old 03-04-2011, 02:06 PM
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shaving .10 off both will make it a total of .20 and that might be to much to mill it down...
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Old 03-04-2011, 09:48 PM
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I hear ya. I think I'm just goin to get the new piston in and find true TDC and then do some measuring. I'm taking brakes, engines, and suspension class at votec. We are going to start engines next week so I'm going to be able to bring it in.
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