79 GS850 with about 55,000 on the odometer. from what i remember when it suddenly died (ran fine for about 2 miles, started bogging down,limped home & never restarted)about a year ago, i traced my problem to no compression (< 50 psi across the board). so i finally got enough time to tear off the head. the pistons look fine, no warpage on the deck or head (gasket looked perfect). i flipped teh head upside down & filled the combustion chambers with penetrating oil to verify valves weren't leaking (not a bit) --- forgot to check cam timing before the teardown. my question is if anyone has had a problem with the chain jumping timing? or is there anything else i should check before sinking $$$ into gaskets and bolting it all back up?
-
-
50 PSI across all 4 I wouls think timing is off ? or the compression test was not done correctly. Need to hold the throtle wide open or take the carbs off. -
I got 50 psi all across the first time I did a compression test. Didn't know throttle had to be open. Did it with throttle open....150 psi.Comment
-
Sounds more like an electrical or fuel problem.1166cc 1/8 ET 6.09@111.88
1166cc on NOS, 1/8 ET 5.70@122.85
1395cc 1/8 ET 6.0051@114.39
1395cc on NOS, 1/8 ET 5.71@113.98 "With a broken wrist pin too"
01 Sporty 1/8 ET 7.70@92.28, 1/4 ET 12.03@111.82Comment
-
i'm starting to think that maybe the compression test WAS done wrong. yeah well, lesson learned. at least with the head off I have a chance to reseal everything (55,000 miles . . wouldn't be bad to replace valve seals. maybe port &polish the exhaust a bitComment
-
To back up a little, yes, my 81 had jumped time once.Currently bikeless
'81 GS 1100EX - "Peace, by superior fire power."
'06 FZ1000 - "What we are dealing with here, is a COMPLETE lack of respect for the law."
I ride, therefore I am.... constantly buying new tires.
"Tell me what kind of an accident you are going to have, and I will tell you which helmet to wear." - Harry HurtComment
Comment