Smoking after rebuild

[MexicanGringo]

Hey all

Just started up after doing rebuild of rings,bearings and seals, all new ring kits and new valve oil seals were installed. The engine is smoking quite badly, is this normal for a short period till the oil & compression rings seat? and if so how long should it take to stop smoking?

[Morespeedvicar]

Hiya,
it'll smoke for a bit while it burns off the assembly oil, but shouldnt smoke for too long, maybe a few miles or so. Did you gap the rings etc when you did the rebuild?
Cheers
Ian

[MexicanGringo]

The gaps were on the large side but still within service limits.. Havent ridden bike yet just idled it for 10mins but it should have burnt off assembly oil by now? It smoked from the start so im pretty sure its rings.. I honed the cylinders myself and used a hone with slightly too coarse stones so im thinkin this may have something to do with it

[NC35]

Just started up after doing rebuild of rings,bearings and seals, all new ring kits and new valve oil seals were installed. The engine is smoking quite badly, is this normal for a short period till the oil & compression rings seat? and if so how long should it take to stop smoking?

It took me a good 30 or 40 miles of hard riding for the smoke to go away after I did the same to mine. What you have there is for all intents and purposes, a new engine, and it will take a little time to bed everything in.

I don't subscribe to the 1000 miles at stupidly low revs, and instead followed the MotoMan method of running it in - basically I caned the heck out of it from day one. However, the slightly too coarse honing stones may have an effect too.

http://mototuneusa.com/break_in_secrets.htm

Personally, I would use a good quality mineral oil, start the engine and let it get fully up to temperature, then take it for as long and hard a ride as you can manage, but pay attention not to over-rev (don't red-line) then engine. Also, try to keep the revs constantly varying, don't go cruising at 10k on a motorway for half an hour, you need to load the pressure on the rings, and the best way to do this is accelerating using half to full throttle (build up gradually). This will help bed the rings into the cylinders.

Don't use a semi- or fully-synthetic oil yet, they are just too good and don't let the rings "wear" against the microscopic peaks on the freshly honed cylinders. It's a shame you've started it up and done nothing more than let it idle, it would've been handy if you could ride it from first startup.

Once you've finished this ride, drain the oil and refill it with your usual oil.

Have faith, believe in your ability to bolt the engine back together properly, believe in the newly built engines ability to take everyday stick from day one, and you'll be fine.

[Cammo]

I don't subscribe to the 1000 miles at stupidly low revs, .... basically I caned the heck out of it from day one.

Amen!

[MexicanGringo]

Cheers thats reassuring you had the same problem, though most people ive spoken to say it shudnt smoke at all after assembly oil is gone? noticed a drop in smoke after idling it a bit, but the plugs are fouling really quickly with oil & rich mixture situation i got. Il have the faith then and see what happens after some riding, christ i really really dont want to have to take it all apart again!!!!

[NC35]

Hehe, I know - I had the exact same fears, last thing I wanted was to hit the starter, listen to a box bits getting made, then starting again.

I now have a very sweet engine - starts on the button every time and pulls like a train through the gears. Its very pleasing when it all comes together.

If you do put in a mineral oil or whatever for the first ride, pay attention to it when you drain it out again - it will have this beautiful metallic sheen to it, where you can see all the tiny bits of metal from the rings and cylinders. Bizarre site, really is.

[Neosophist]

I'm with you on the bedding in procedure.

Decent mineral oil is the way to go (and its cheap! :D)

I tend to use upto 80% of the engines rpm range for the first 650 - 1000 miles, varying the rpms and gears to let everythign heat / cool and bed in properly.

Then ditch the oil and away you go :-)

That an interesting link.. i'll bear that in mind :-)