Polar_Bus
Well-Known Member
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- 754
So I've run about 1 tank of fuel heat cycling my new engine (dam this takes FOREVER ! ). I thought I would do a compression test on my engine and post the data for others to reference. When you do a compression test it's a good idea to set the throttle to wide open to allow max air to enter the cylinder. It took me 4 pulls and my engine reached maximum psi at about 100-105 PSI. Now I have a baseline for top end maintenance moving forward. Most of the 2 stroke motocross engines recommend you change the piston ring after 10 hours. These engines only use a single ring design, and i'm sure the quality is crap so once I see a drop in compression or I seem to have trouble tuning / poor top end performance I can just do a compression test and it will tell me the condition of the top end. My compression may come up a little bit as the rings take a set but i'm guessing not much. Lastly if you do observe low numbers, say 85 psi , try adding some oil into the cylinder and re test. If your compression numbers jump up then you now know you have top end issues.
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