TOPIC:

Hi Guys, how long does it take to seat new rings? I have 100 miles on a rebuilt engine and cranking compression with engine cold is right around 100 for all cylinders. Is this reason for concern or do I need more miles to get them to seat? 



 

You shouldn't baby the engine.
Ride it as normal but don't over rev or stick at constant low revs.
Make the engine pull and use plenty of engine braking to push the rings into the bores,
Going too steady can glaze the bores.

How long should I have to do that for? Im worried there is something wrong 

500 miles, and follow Zed1015s instructions.
And if you think that is long. I used to be an over the road truck driver.
 A C15 Cat will take about 80,000 miles before they would start to pull good.


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Also, is your compression tester good. I had a brand new one showing 75 on all cylinders with the screw in adapter.

Tried it with the rubber push in adapter and straight away it was over 125 and blowing past the rubber foot.

This was on a brand new tester.

As woodyvale suggests, it could be your tester. What kind are you using?
If it's a hose type, you need the type with a valve stem in the part that threads into the head, not the type where there is a hose and the pressure release is up at the gauge because the internal volume of the hose will be added to that of the cylinder. The cheapo Harbor Fright will give you low readings every time.
The solid hand held tester with the rubber knob works best if you can get it on the plug threads.
 

wrote:

How long should I have to do that for? Im worried there is something wrong 

Just ride the bike as normal and forget about all that 500 mile running in cobblers.
Just don't thrash it for the first couple of hundred.
As for the compression, as long as they are all within around 15 psi of each other and it runs ok i would just concentrate on riding it.

 

I agree with Zed and trying a push in type comp gauge. Every 30-50 mile ride I took after warm up I'd end up at my fav blacktop that has a slight incline. I'd put it in 4th and roll it on at 4,500 and run it to 7,000............ then shift into 5th and baby it to cool things a little. I'd do this 2 or three times to really load things but not being too rough on it. There was a great article way back on here that thought this was a great way to seat new rings and I remember quite a few of the guys on here liked the idea.

Be sure to hold the throttle wide open and "warm" the engine before testing also....... I had 165 on all 4 before I started it and 170 a couple hundred after..........

thank you all for the responses. Im starting to feel more confident.

I was using a cheap hobo freight compression tester. I was able to pinch the hose together with my fingers so Im sure it's not accurate. Will put some more miles on and retest with the push-in adapter. 

Compression should be 150 plus on all 4....about 500 miles to set in the rings

Any fresh motor that still smokes after a few minutes of running means something is screwed up!!!!

I have checked compression on a few of my fresh motors after a short test ride, the compression was always within a few pounds of what it was supposed to be!!!!

Best way to get the rings to break in is on the very first ride get into 3 gear or so and around 3 grand or so start loading the motor and let it run up to 6 grand or so. Then let it coast down to 3 grand and repeat that process 3 or 4 times.

 

I've been doing exactly that. Went down the backroads today and varied from 3000--5000 in 3rd with lots on engine braking. Have right about 100 miles of break-in time now. I think I was freaking out because of a cheap tester and cold motor. 

Only made it about 30 miles before my license plate fell off though--which explains that annoying noise I heard coming from the licence plate. Had to go find it and carry it back home under my arm.