Burning oil

[willybell_uk]

Hey guys

Just in the process of stripping my Firestorm. I converted it to a trackbike but was black flagged at Cadwell for burning oil (smoking from the exhaust), prompting the stripdown. The bike used a good litre of oil during the day.

I have the heads off and about the split the cases, my suspicions are bore/rings or valve guides.

I've noticed a few things:-
Both piston crowns were oily, not wet and dripping but damp. Both seem the same in this respect.
I can see honing marks on the bores although the engine has done 33000 miles. Nothing else obvious.

It's early days (no measurements yet) but as I'm new to the engine I wondered if anyone had any thoughts.

Thanks,
Mark

[bigtwinthing]

a comp test would have been worthwhile before a strip, sorry!

[willybell_uk]

Yes, you're absolutely right, never gave it a thought at the time!

Mark

[bazza696]

how old was the oil in the bike when it started burning it.

Mine burns oil when the oil is past its best, that's how I know it's ready for an oil change.

[willybell_uk]

It was fresh oil Bazza.

[Pete.L]

If there is honing marks I would be tempted to have the rings checked for correct size first.
May as well check the valve stems for wear and change the seals whilst you are there. Hope you thought to check the airbox before you started. If you had a load of oil in the airbox from the breather tubes it could have just been over revved too much

Pete.l

[tony.mon]

Its not too much work to strip the sump off, then undo the big end bolts.
You can then push the pistons and conrods out of the top of the bores.
Now you can see the pistons skirts to look for signs of scoring or broken lands, the bits between the ring grooves.
If there is no apparent wear, then it will be valve stem deals.
You might wonder why you don't look at the seals first, but it's a bigger job to replace the seals and then find that it was the pistons all along and have to strip it a second time.
You can remove pistons with the engine in the frame, btw.

[vardypeeps]

Found my 2004 SV650 would push oil past at high revs but you could only smell it and not see it.
1ltr is a lot, hope you find the issue