Jump to content
Sign in to follow this  

Seating rings...

Recommended Posts

I have just rebuilt my 2012 XR650L, new valve seals, Wiseco 102.4mm forged piston with rebore. The engine now has about 1400 miles on the rebuilt top end. She smokes a little, particularly when the throttle is whacked and when throttle is released. It smokes more when hot and not so much when cold.

It is blue smoke (light, not heavy amount) and overly rich jetting has been ruled out. Pulled the plug and it looksgreat (light tan).

I assume the rings still need to seat but am concerned given the amount of miles since installed and am torn between waiting or ordering another set of rings with a re-hone.

Can it take a while for the rings to seat? Piston was installed dry without excessive oil. It was broken in properly, varied throttle, hot.

Any opinions?

Share this post


Link to post
Share on other sites

If you dont seat the rings in the first 100 miles it is NOT going to happen  you would need to pull the head and rehone the cylinder  to get the cross hatch back  then you need to use plain NOT synthetic oil and ride it like you stole it - fast up full throttle and fast down full chops,   the  compression behind the rings on full throttle and full deceleration is what applies the pressure to seat the rings.  never keep it at the same RPM for more than a few seconds,  better to do it on a very low traveled road..  on a brand new overhaul you may want to do a few short 4-5 mile runs to get the heat up and down a few times make sure your clearances are good,  then build it up to a 20 or 30 miler,  been doing them all that way for years never a problem with smoking until it is way worn out ,  there are a lot of write ups about it. 

 

JMHO

  • Like 1

Share this post


Link to post
Share on other sites

The rings are mostly seated in about 5-10min . and as good as they're going to be at 20-30min. I've tested a few motors just by cranking over a few times , then after a first firing(2-4minutes) , and then after a second heat cycle(10-15minutes) .After that first few minutes running they are already at "normal" compression ,and get a little better after the next then settle there.

Edited by jjktmrider

Share this post


Link to post
Share on other sites

I've ordered rings and new valve seals, time to go in again, I guess.  One question, I used the supplied cosmetic head gasket with the piston kit, is it possible a leaking head gasket could cause my problem???

Share this post


Link to post
Share on other sites

...is it possible a leaking head gasket could cause my problem???

I've rebuilt a bunch of different bike engines over the years and have never seen a head gasket cause oil smoke out the pipe.  It may be leaking but, in my opinion, the head gasket won't cause your problem.  I also use a bunch of Cometic gaskets and never have issues.

 

That smoke can be caused by other issues though.  Incorrect size bore, out of round bore, incorrect hone, ring gaps incorrect, rings installed incorrectly, etc., are other things to look for.  Just because an engine shop did the work doesn't mean it is correct.  Take it somewhere else to have dimensions verified.  It doesn't have to be an engine shop.  Get your required clearances and any machinist can give you accurate dimensions of your current stuff if you don't have the necessary tools to do the measuring yourself.  Anyone can be careless or have a bad day machining.

Edited by hollerhead

Share this post


Link to post
Share on other sites

do those have valve guides???

 

speaking for myself and talking (at least) dozens of harley motor rebuilds,,,

I've never seen a cometic head gasket fail...

their the best you can get and cost more usually...

IMexperience I think a head gasket failure is more pronounced than that...(a little smoke when whacked or released)

 

also add I ALWAYS hand rub oil in the cyl and outer piston on assembly...

Edited by THUMPERRRR

Share this post


Link to post
Share on other sites

Were the ring gaps checked at assembly? People tend to just throw rings in assuming they're correctly gapped. Usually they are but not always.

  • Like 1

Share this post


Link to post
Share on other sites

UPDATE:  The pig does not smoke as much now, if at all, only detectable when the throttle is whacked, not sure why if the rings should have seated shortly after the first start or two.  I did have to go up on my jetting, not really sure why as everything I have read suggests it should have stayed the same or even gone leaner with a larger bore and higher compression piston.  I am now at 52/158 and yes, that main seems fat but my engine definitely needed it, last plug inspection the porcelain was white and I still had some pre-ignition issues at WOT.  Pilot jet is good, with the 50 it would die one turn out from the stop, now it dies 1/4 turn out from the stop and I am at about 2 turns out on 52.

 

There may be some merit to a big bore kit needing a pumper carb but the bike runs well and I am happy with it.  I did order an extra set of rings just in case I needed to go back in the motor...

Edited by condershire
  • Like 1

Share this post


Link to post
Share on other sites

As others have said, get it fired up and then flog the crap out of it for a few miles... done! Neighbors love it when I re-ring an engine!

  • Like 1

Share this post


Link to post
Share on other sites

As others have said, get it fired up and then flog the crap out of it for a few miles... done! Neighbors love it when I re-ring an engine!

 

That's how I do it too.

 

The higher cylinder pressure seems to seat the rings quickly.

Share this post


Link to post
Share on other sites

That's how I do it too.

 

The higher cylinder pressure seems to seat the rings quickly.

Here's the script: "Honest officer, I have to ride like that. I am seating new rings. It will save gas and burn a lot less oil over it's lifespan this way. I am being environmentally responsible."

  • Like 1

Share this post


Link to post
Share on other sites

Or from the wife.....  "It's 12 at night are you trying to make every neighbor hate us?".

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...