6 replies to this topic
  • Guest_mxrider426_*

Posted August 01, 2002 - 07:25 AM


Does anyone know how much compression a 426 should get if you do a compression test?

  • therapture

Posted August 01, 2002 - 07:55 AM


1) push kickstarter to TDC

2) DO NOT pull compression release

3) stand on the kickstart lever.

4) if the lever won't go down within 2-3 secs, you have plenty of compression :)

J/K- I do not remember the actual numbers pal...the manual has it in there?

  • freestyle111

Posted August 01, 2002 - 10:07 AM


anything below 120lbs start thinking about rings

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  • Shawn_Mc

Posted August 01, 2002 - 02:04 PM


On a test, Id be looking for about 180 psi. Your going to have to bump it (push start type) to get a read, because if ya pull the comp release...get the idea?

Get it rolling pretty good in 3rd or 4th, and remember the throttle should be wide open.

  • freestyle111

Posted August 01, 2002 - 05:29 PM


you can also use long 1\2" ratchet with 14mm socket just remove ignition cover plug and turn motor over wwith flywheel nut

  • Guest_mxrider426_*

Posted August 01, 2002 - 06:51 PM


I can't find a fitting for the comp tester that fits the plug hole. Anyone know where to get one?

  • freestyle111

Posted August 01, 2002 - 07:49 PM


instead of speading $150 on leakdown tester i made my can make a compression tester same way.i busted out the ceramic inside of old spark plug then tapped inside plug [1\4"tap].i then bought a grease gun hose.1\8" fittings on ends.i also bought 2 1\8" to 1\4"couplers and attached spark plug on 1 end and compressor fitting on would only need to use coupler for plug end compression test gauges have 1\8" inletPosted Image

[ August 01, 2002: Message edited by: freestyle111 ]

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