Re: Engine & spark plug Condition info, FYI

Posted by Bob E. On 2016/5/30 16:57:19

Here is an update. I did not perform the compression test as per the manual so I repeated it plus bought a cylinder leak tester (OTC 5609) as per Jack's suggestion:

Compression test was done with engine warmed up from driving around, all plugs removed, throttle blocked full open, and charged/strong battery. Test was done 'dry' with no additional with oil squirted in.

For the Cylinder Leak test, inlet pressure was set to 100 psi.

Cyl, Compression, Cylinder (leak test) psi, Audible location of leak

1, 120, 92, Oil vent/fill tube
2, 120, 90, Oil vent/fill tube
3, 125, 92, Oil vent/fill tube
4, 110, 94, Oil vent/fill tube
5, 120, 92, Oil vent/fill tube
6, 110, 88, Oil vent/fill tube, maybe exhaust
7, 120, 92, Oil vent/fill tube
8, ---, 91, Oil vent/fill tube

(Tried repeatedly but gave up getting compression tester hose into #8....)

Big difference in results by doing the compression test as prescribed. The leak test numbers surprise me as to how high they are. I repeated the tests and got the same values. Odd that #4 had lowest compression but also has lowest leak rate. Any comments regarding the results or test setup are appreciated.

thx
Bob