All the Harley's breath a sigh of relief

[DRedel]

I joined the forum because I was having problems with my pick up system. Thanks to all the members here who helped me out. I took it to a local mechanic to have my carbs synced and get that final dial in for the season. I had him do a compression test to just make sure that everything was cool. That's where everything spiraled downward. Got super low compression. We dug deeper. I have a dead cylinder and the rings are shot. Im gutted. I thought I was putting the icing on the cake and instead now I'm finding out that my bikes done. I can't part it out. I think it's gonna get parked in a corner while I save up for a big bore kit. Or keep my eyes open for a motor. Any leeds let me know. Thanks again to everyone for helping me out. I'll be back out someday it's only a question of time and money.

[natemoen]

You can get rings for $70 or less.

[TopCatGr58]

Hold on there a minute!!

Hey Dredel,

I can't remember all of the specifics of your machine, like how long had it sat before you started to bring it back to life? How many miles on the engine, and how many have YOU put on it getting it ready to run? WHAT are the comp values, and did the mech do it with the THROTTLE WIDE OPEN?

Also, I would assume that you have checked and set the valve clearances to the spec levels, so yes, that would leave the rings, but folks have reported low comps on engines that have sat for years, with mild rust and such, they used MMO or sea foam in the oil, ran it for 5-10 minutes just on the centerstand, no heavy revving or engine load, just slowly up to normal operating temps. Then allow to sit with the MMO in/around the rings for day, maybe even squirt some into the spark plug holes after it's warmed up, and then let it sit for a day. THEN drain the oil/filter and refill and then RUN the bike for a few hundred miles and then retest the comp levels...you may get pleasantly surprised!

T.C.

[DRedel]

Mines a bastard xs midnight special that had sat for 5 years before I got it. I ha the carbs rebuilt and breaks rebuilt. I changed the valve cover and the oil pan. I replaced the pick up coils. I also had to change the clutch cable and the throttle cable. The bike has like 20000 miles. When we did the compression test the numbers were like 45 60 90 and 80 but I can't remember which cylinders were what. I felt sick in my stomach and had to leave. I went back today and he had adjusted the valves and put them back into spec. He also did a leak down test and said that all of them were off by different amounts. They were not all off by a constant across all cylinders. He said that the Vaccume to my octy was on a weak cylinder so he switched it. But he said its done. I have to go get my bike so Let me know if there are some more specific questions to ask him

[TopCatGr58]

Sounds like he's not familiar with carbed bikes, and probably did the comp test with them on, and didn't open the butterflies/throttles wide! Several folks have reported similar values, but then got much better once they OPENED the throttle plates!

20k miles is just broke in....get it out of the shop, run for several hundred miles, blow as many harleys off the road you want, enjoy it, and THEN if you want, recheck the comp levels.

If you can change your oil/filter yourself, then since you may already have fresh oil in it, run it for a few k miles, then put the MMO in it as described earlier, and the drain/filter and put in new.

T.C.

[DRedel]

Whats MMO? Is it the same as seafoam? I want to change the oil and filter so if it's not bad I will just try it now then run it.

[WSL91]

Whats MMO? Is it the same as seafoam? I want to change the oil and filter so if it's not bad I will just try it now then run it.

MMO is Marvel Mystery Oil. It resembles auto-trans fluid. It's used some times to un-stick rings that are not seating and may be stuck in the ring lands (Grooves). Stuck rings are a caused by setting for long periods.

[natemoen]

But he said its done.

A hardley may be done at that point but people have had worse compression numbers than that!

[DRedel]

How much MMO should I put in my oil? Should I drain some oil then fill it up to the proper level? Thanks Dustin

[DRedel]

Should I do the seafoam and the put MMO in the spark plug holes. Should I do both.. Haha

[petejw]

dont know if the bike was at operating temperature
or not but if he checked the compression with a cold
engine those numbers wouldnt be accurate anyway.
do as the others have said, take it out of the shop
ride it and see how it goes.

[natemoen]

Forget the mmo and seafoam. Go get the bike and ride it. After you are done riding for the day redo the compression test and hold the throttle wide open as you crank the engine for the test.

Then forget about the numbers and ride the thing.

[soccer4m]

ride it

I agree with the other folks, 20000 is nothing for these bikes.. pull the plugs, squirt a few ounces of mmo, or tranny fluid, let soak overnight, put the plugs back in and ride it hard for an hour or so. It will smoke a bit out the exhaust until the oil burns out. I think we can guarantee your compression will be way up. Also, change the engine oil if you havent already, many a xs has had leaking carbs that dilute the engine oil and also causes really low readings, and abnormal engine wear....try some thicker 15-40 wt. So, go ride and when you check it out there should be a smile on your face....Mike in SUn DIego

[DRedel]

I'll take it for some rides and figure everything out and I'll let everyone know what happened. I need new tires but I guess I'll get some cheep ones and roll the dice. Thanks all. Dustin

[mharrington]

I have the engine out of a wrecked 79 special. When I bought it the owner said it ran great but then was wrecked and parked beside a shed 5 years earlier- out doors with a supposed canopy. The bike looked like it had been pulled from a swamp. I put a little oil in each cyl and got 0-40 psi reading cranking with no carbs. NO chance to run the bike as the wire harness was basically gone. After a read here on the forum I added MMO in the cylinders and squirted it over the shim buckets in hopes some would lubricate the valve guides. The next day the readings were 80-120. Im confident if the motor was run everything would have came back. The motor is a parts motor for me.