While working on my 76 1500 midget because of some starting problems I decided to change my plugs. While I was changing my plugs I figured I would do a compression test. My dry results revealed #1@155, #2@120, #3@125 and #4@125.
I asked the question: Is one high cylinder an indication of a bad exhaust valve or are 2, 3 and 4 low? I can't find any specs that say what compression should be? Does anyone else know on a 1500?
Morris responded as follows:
I'd say #155 is about right. Low compression could be a whole slew of things. I would run some Sea Foam through the intake and see if that doesn't bring your numbers up. After that, you can squirt oil into each plug hole and see if that does not bring your numbers up. If your compression comes up after squirting oil, the problem is likely your rings. If not It's likely your valves... or a blown head gasket, which in my experience is super common on 1500s.
And so I did not yet do the Seafoam but I did 3 squirts of 30w oil in each cylinder for a wet test and the results were as follows:
#1@195, #2@190, #3@210 and #4@170
Anybody have any thoughts now?
Thanks!
Jeff
I asked the question: Is one high cylinder an indication of a bad exhaust valve or are 2, 3 and 4 low? I can't find any specs that say what compression should be? Does anyone else know on a 1500?
Morris responded as follows:
I'd say #155 is about right. Low compression could be a whole slew of things. I would run some Sea Foam through the intake and see if that doesn't bring your numbers up. After that, you can squirt oil into each plug hole and see if that does not bring your numbers up. If your compression comes up after squirting oil, the problem is likely your rings. If not It's likely your valves... or a blown head gasket, which in my experience is super common on 1500s.
And so I did not yet do the Seafoam but I did 3 squirts of 30w oil in each cylinder for a wet test and the results were as follows:
#1@195, #2@190, #3@210 and #4@170
Anybody have any thoughts now?
Thanks!
Jeff