Compression tester

[nigel_bytes]

Just got one of those cheap compression testers, a tenner from Amazon (free delivery too)
You get what you pay for, tried it this afternoon
No reading on a good engine with plenty of compression, Problem with one way valve, see below,

Had to think of a solution, so i tried a longer valve and weakened the spring, Result: it now works

[littleredrooster]

...and don't forget to hold the throttle wide open while you crank the motor. Many people spend hours trying to find the missing compression.