-
-
I just talked to one of the Master Certified service techs here ( Auto ) but he is a gear head to be all gear heads and has more toys than any one man should be allowed...and he stated that at the very least, you could expect to have a ROUGH idle and if were his, he would tear it down and check the ring ridge (amount of wear that the cylinder has at the very top where it meets the head), and then compare that to where the piston rings have been wearing on the cylinder itself.
My feeling is that you may have a rebuild ahead of you...Comment
-
Here's something odd,...
My Clymer manual calls for PSI somewhere between 128 and 171, with it not varying more than 28psi between cylinders. And it says that an engine overhaul wouldn't be due until one or more cylinders dropped below 100psi.Comment
-
Yea...I looked at the specs myself, and they stated exactly what you've said.
When you throw the Marvel oil into the mix, you can expect the numbers to climb a bit due to there being no or next to no air getting past the rings. Also, depending on how much you put in, you are displacing volume within the cylinder and that with the extra air retention will make the compression readings spike.
Comment
-
So, none of my cylinders vary more than 28psi, and none are below 100psi, even though 125psi isn't great, so shouldn't this indicate something else is wrong?Yea...I looked at the specs myself, and they stated exactly what you've said.
When you throw the Marvel oil into the mix, you can expect the numbers to climb a bit due to there being no or next to no air getting past the rings. Also, depending on how much you put in, you are displacing volume within the cylinder and that with the extra air retention will make the compression readings spike.Comment
-
My instinct is all this has nothing to do with rings. Your dry compression test was well within acceptable limits and should NOT be causing this kind of nastiness. Worst you could expect from that slightly-off compression is maybe some oil use and power loss, although I don't think you're anywhere close to the point where you'd have really any noticable symptoms.
Sorry to re-iterate, but you HAVE adjusted your valves, right?Comment
-
I think that it is still a combination of issues...I still wouldn't rule out an intake/ air leak. I know that I fought with that issue until I was ready to nuke the thing in neutral. Eventually after checking and rechecking AGAIN, and AGAIN, and AGAIN, the list of problems got so short that I was looking for a single issue.
All of them added together are making this project of yours very hard to diagnose and even harder for you to rectify. It only needs three things to run Spark...and you have that. Fuel...and you have that. And Air (compressed)...and that is where we are now.Comment
-
=; STOP!
Why eye aughtta... ;-)
Get those valves adjusted, ya goof! Aside from possibly fixing your compression (it did mine), misadjusted valves can cause you all kinds of headaches. I wouldn't spend another minute on this until those valves are in spec.
I put it off for a long time, too, but it's really quite easy PROVIDED you have the right tools. That means a tappet depressor so you can get the shims out, and a digital caliper so you can accurately measure them (the markings are often way off). I got the "shim tool" (tappet depressor) on eBay for $18 but they can be had retail for $25-$35 at any parts website. Digital calipers are like $10 at Harbor Freight.
DO IT!Comment
-
Okay, okay. One more thing to tackle.
Although, I thought if you poured oil in and the psi's rose, that indicated that it wasn't valves.Comment
Comment