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I'm at the end of my tether with a smoking Bullet 500 Engine. The wet sumping isn't bad but the burning of oil is ridiculous. What have i tried so far ? Head off - new guides and valves checked and reground, barrel off - piston gaps checked and in tolerance all down barrel, rings checked right way up, left overnight with oil on top of piston - no leakage. What am i missing, the bike has a high pressure / capacity oil pump - could this be delivering too much oil to the valve gear ? ( could fit pressure relief valve from Mr H but want to be frugal ). I tried fitting valve guide oil seals before and they were a fiddle and rapidly broke up, and i'm fed up with having to decoke the thing. I'm really at a loss and its an embarrassment to ride the beast like riding a destroyer laying smoke !

Help !

Chris

After doing all that it could be a glazed bore. Even worn rings will seal with oil when the engine is not turning over. I would get the bore honed and see if that helps. Also are all the breathers clean and unblocked

I'm wondering why you need a high capacity/pressure oil pump? In my experience if these old plodders are used correctly more oil at higher pressure is really not required.The valve guides and piston rings might be perfectly good at normal pressures, but increasing it might have been too much. I'd try the standard oil pump and check the breather system is all clear too.

Hi Chris, Make sure the conrod isn't bent [even slightly] to one side, this will tilt the piston over to one side slightly and cause terrible oil smoke. It needn't be the end of the world if it turns out to be the case with yours, I had it happen on a 350 racing Bullet engine a few years ago, all the ring gaps would eventually line up because the piston was tilted over. I fixed it by carefully straightening the conrod in situ and finally the smoking stopped. Prior to that, I had tried rings, valves and guides, but none of those changed anything. Regards, Paul.

Overfull oil tank?

Until you find the real cause of the smoking; I would suggest using Castrol Edge Titanium 25/50. It will reduce oil consumption in normal operation.

There is a problem present that a change of oil make or grade will not cure Leon.
I would suggest that the drillway from crankcase to front drain plug where the scavenge pump lifts the oil is partially blocked.
Not theory but actual experience. Took me a long time to find why I was using a lot of oil and the bloody thing smoked like a bastard even though evrything was mechanically sound.
So Chris when you do your umpteenth decoke lift the barrel & check how much oil is sitting in the bottom of the crankcase, turn the crank half way & see if the flywheels have a coating of oil, use a dipstick of some sort to see how much is down there.

Sorry, But for quick clarification please remind me, does the engine belt out white smoke all the time it's running or just on start-up?. A

Sorry to add another possibility, but did you buy this bike with the oil pumps fitted, in other words, has a Previous Owner worked on it? If so, and the PO changed the piston or rings, it could be the rings themselves. I have had Indian rings which never bedded in properly despite being apparently to the right specs. Changing them to European made ones from our Hosts sorted it.

REgards, Mark

Wet sumping and oil burning for 'no apparent' reason, and with High Cap oil pumps fitted...


I have seen far too many sets of High cap oil pumps where both pump disc have identical portings. Check both pump discs and ensure that the ports are not identical.


Next check the fit between plunger and disc: they MUST me a tight snug fit with next to no clearance.


If the new pump disc have not been finely lapped into their respective seats in the timing cover so that they are PERFECTLY seated, you will be farting against thunder; wet sumping and poor return will plague you forever.


Make sure that you have the correct sealing gasket/ring fitted to the crankcase drain plug. Too thin or missing and you could be partially blocking the return oil pick up flow.