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  1. #1

    gp800 compression with stock head

    whats the most compression that would be safe to go with on a gp800 motor and a stock head.and do these motors have the same issues as the 61x and 62t cyls cracking so would a girdle kit be nessicary im looking to get about 190 and run 100octane with a stock head will i be ok

  2. #2
    Compression on a stock engine is 120/cylinder. No cracking issues however there is no reason to run high octane with stock compression. You will slow yourself down the higher you go. Its the opposite to a 4 stroke. You wont lower octane for a hotter burn in the 2 strokes. When you bump the compression then you are forced to run higher octane to avoid detonation and so forth.
    Stay with what you have and run 87!
    Bumping just the compression and nothing else aint going to be worth much and that ski, plus you need the bigger carbs to get more fuel in with that king of compression. If you were going to mill the head I wouldn't go any higher than 150.
    What other mods are you doing?

  3. #3
    why would the size of the carbs have any effect on how much compression im running are the carbs not big enough from the get go for that building a freestyle motor with it it will have a pipe and the timing changed ported ect

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