Oil pump

temple_of_boom · Post by **temple_of_boom** » 29 Oct 2003, 09:00

Hi all,
I may have a problem with my oil pump (MkII). It seems to be allowing oil into the engine when the bike is standing overnight. If I leave the bike over two nioghts, then I can forget starting it till I've whipped the plug out and primed the cylinder with a teaspoon or two of petrol, otherwise the plug just gets oiled.
I took the pump off but cannot figure out how it works (my first two-stroke). I have connected a plastic squeezy bottle of two-stroke onto the inlet pipe, and bled the air out. However if I squeeze the bottle I can't seem to flow any oil through to the exit pipe, regardless of the position of the pulley. I expected that the pulley would open and close a valve to meter the oil. I rotate the worm drive clockwise (looking from the engine side of the pump), this seems to turn an impeller but no oil appears at the output
So now I'm totally confused. On the one hand, oil gets into the crankcases when left standing, and on the other hand the pump doesn't appear to flow any oil at all. I'm thinking of ditching the thing and premixing (any ideas on ratios anyone?). help!

Russell · Post by **Russell** » 29 Oct 2003, 10:20

Maybe the oil is coming through the crank seal from the gearbox. The oil pump puts oil in the engine via an outlet in the inlet manifold, therefore a quick check is pull carb off after standing for a couple of days, if oil pump is problem the inlet manifold will be full. If not suspect main oil seals.

Bargos · Post by **Bargos** » 29 Oct 2003, 10:42

The oil pump only squirts oil in when the engine is under load, ie. running or being kicked over.

Post by **admin** » 29 Oct 2003, 13:31

Yep, deffo sounds like the right hand crank seal. Only way to do this properly is a motor split. on that side i think the seal is retained by a groove hence pulling it out and pushing a new one on may not be possible. Also while its down put a pair of outer mains on the crank for good measure

temple_of_boom · Post by **temple_of_boom** » 31 Oct 2003, 02:36

Thanks everyone. The motors on the bench at the mo, so there's no kicking and no carb involved. I'm having a little difficulty removing the nut holding the primary drive gears on the crank. I'm anticipating similar issues with the clutch basket. I'm intending to get a clutch basket tool from MPS and I'm hoping that it'll fit the rotor as well. Has anyone got experience/recommendations with this or other similar tools?
When I replace the clutch cover, should I grease the gasket or does it need gluing instead? Equally if I have to split the cases does the centre gasket require gasket cement or is it one of those with built-in glue?

phil1 · Post by **phil1** » 31 Oct 2003, 17:14

i had a prob recently where 2 stroke oil was getting into the gearbox oil, this was caused because the oil seal on on of the nylon drive wheels had slipped forward, this apparently happens on mk2`s (thanks LT).
it appears to be cured now as i have just pushed it back.
the symptoms were oil blowing out of engine breather.
i cant understand how the oil would get to the plug until you kick it over, if just left overnight, is it just harder to start and therefore oiling up, due to the petrol oil mix being sent to the engine?

temple_of_boom · Post by **temple_of_boom** » 02 Nov 2003, 02:16

I've connected an oilfeed to the pump now just to see whether it leaks at all, and after two days it doesn't. I'm going to replace the pump seal just in case. The plug would oil up after I kicked it over. I could see the oil level in the plastic sight tube decrease overnight and in fact over the following night too. Generally it would start OK after being left overnight but not if left two nights. When I took the barrel off (it had been standing two years by then) the crankcase was full of oil nearly covering the crank webs.
I got the clutch off by bolting a steel rod to the final drive sprocket to hold the gearbox still, but still can't shift the nut off the end of the crank. Demon Tweeks do a rotor-holding tool but it's forty quid. Suggestions please.

easyryder · Post by **easyryder** » 04 Nov 2003, 08:21

i had a prob recently where 2 stroke oil was getting into the gearbox oil, this was caused because the oil seal on on of the nylon drive wheels had slipped forward, this apparently happens on mk2`s (thanks LT).

Phil could you just explain this for me please ie where's the seal and wheel? I have had the same symptoms - oil blowing out the breather, down the swinging arm onto the brake pads!

phil1 · Post by **phil1** » 04 Nov 2003, 19:21

well i have routed the breather pipe into the airbox, (to stop it vacuuming up water from puddles) and after a number of rides the airbox had a lot of oil in it. i thought at first it was water and replaced the seals on the water pump. this didn`t stop it so after a chat with leasure trail, off came the right side cover (drain oil 1st!) and there are 2 nylon drive wheels for the 2 stroke oil pump, on one of these the oil seal had slipped forward, push it right back into the caseing and hopefully problem cured. doesn`t happen on later models due to a modification. Phil.