Oil in the crankcase - Where from ?

Toad555 · Post by **Toad555** » 29 Jan 2006, 19:32

Hi

I'm more than a little concerned about this one, my bike has been a fairly long term restoration project and I've not really done much with it since a few weeks before Christmas.

When I first bought the bike it was a non runner, I found the crankcase to be full of oil and the oil tank was empty, made me kinda suspicious of a problem.

During the restoration I obviously cleaned all this out and took special care to ensure the oil pump was properly adjusted, I also looked as well as I could to check for a crack or gasket leak between the crankcase halves. I couldn't see any problem and there was no other reason to split the halves so I didn't tamper any further.

The bike was completed a couple of weeks before Christmas but I couldn't afford to proceed any further and get it registerd etc, also seemed no point while the weather was really bad. At this point the bike did start and run quite well but was really smoky.

Anyways I've just come to start it now but it just keeps oiling the plug up. Has anyone had experience of this, can oil leak in from the gearbox or is it more likely to be a oil injection pump problem.

Is there any way to tell if the oil is 2 stroke or gear oil, the only plus point that I can see is that the 2stroke oil is red.

Trouble is the oil on the plug just look like oil, not really red. I haven't stripped it again yet but fear I may have to, any ideas welcome before I go down this route.

Thanks
Toad.

CRMR · Post by **CRMR** » 29 Jan 2006, 20:03

You could allways disconect the autolube and drain out to 2 stroke oil and use a PREMIX within the petrol ,If it still smokes after that then is oil in the crankcase that must be burning up through the piston , PM bargos ,, He knows all about this area of the engine..You not overfilling gear oil are you

Toad555 · Post by **Toad555** » 29 Jan 2006, 20:34

Hi

Thanks for that info, I was thinking along similar lines, it won't damage the autolube pump then by running it dry?

Also there is a possibility that the gearbox could be over filled, do you think this could cause a similar issue.

I filled it with what seemed to be the correct amount as listed in the leisure trail manual but none came out of the level plug so I stuck some more in, I think with hindsight the oil takes quite some time to reach the level plug hole, especially in the dead of winter....

I'll investigate these 2 things and also PM the guy you just mentioned.

Jue

kinney · Post by **kinney** » 30 Jan 2006, 23:00

Hi Jue,
Was the oil you found in the crankcase the same as what was in the gearbox or was it the same as what was in the 2 stroke tank

If it was light brown in colour, it is likely it is from the gearbox. Especially likely if your 2 stroke oil was red

Over filling the gearbox will not normally put oil in the crankcase.
A damaged clutch side oil seal will let gear oil into the crankcase, as will a leaking mating gearbox/crankcase casing face. (The vertical joint between the two crankcase halves)
Try running the engine on a 40:1 premix. The oil pump wont mind a bit just for a test run. Once warmed up, if its still smoking, chances are its the clutch side crankshaft oil seal.

Andy.

Toad555 · Post by **Toad555** » 30 Jan 2006, 23:10

Hi

I'm thinking its more likely going to be the clutch side seal too. Not that bad and at least its only a few quid.

I've not stripped it again yet to check the oil colour, I suspect its gear oil tho too. The oil thats ending up on the plug doesn't look red but I know thats no cast iron guarantee that it wasn't once.

shemston_crm · Post by **shemston_crm** » 31 Jan 2006, 00:56

id recomend running around 25-30:1. 40:1 seems abit leen i run mine at 27

over filling the gaer box oil will normally just mean u blow abit of oil out the breather.

if u have oil coming through the seals then i would have thought when running it would leak the other way also putting fuel through into clutch side check that your gear oil hasnt gone to grey mayanaise texture if so then its time for crank seals

hope you figure out soon