Losing Oil

[erkishhorde]

Topped it off, replaced the plugs and took it for a scoot. Seemed fine. Ran about 20mi at 70mph and did some casual twisties for 35mi. Stopped for lunch for an hour and then scooted 30mi home at 75-80 and didn't notice anything. It might have sounded slightly more throaty than usual but that might just be my imagination.

I may not keep the best maintenance records but I keep up with my regular maintenance and don't thrash the bike a lot. The vacuum leak thing is just a suspicion. I was having problems with the fuel pump a long time ago and replacement pumps would seem to work at first but then crap out right away and the engine would starve. Couldn't figure it out and ended up putting on an electric fuel pump and haven't had any problems since.

One thing that strikes me as a bit odd is that the plugs don't look the same as they did when I took them on out on Saturday right after the problems. The horizontal plug looks the same.


But the vertical plug is oily and dark. When I looked at it on Saturday, it looked the same as the horizontal.


Anyway, the bike's on the stand now and I'll see how much oil I need to add  if any now that I've run 80mi.

edit: Bike has been on the stand for a few hours now and I don't see that the oil level is low enough to merit even topping it off. Hopefully I'm just worrying about nothing?

[the_Journeyman]

My M750 uses a little oil between changes, not even a half-quart if that much.  I've got half the mileage you do, so maybe it's just burning a small amount of oil that's not serious enough to worry about.

JM

[greenmonster]

I have to admit running my bike w 0.4-0.5 L too little oil!
Done it several times on two 2valvers w/o problems.

I think it is time a check for valve steem oil leakage & even more likely rings are worn.
And do not worry, just time for hicomp pistons + overhaul.  
Just my 2c.

[bikepilot]

That's a lot of oil on that vertical plug - indicates that lots of oil is getting into that cylinder.  The plugs on my H1 aren't that oily and its a two stroke.  I don't have a ton of experience with 2v engines, but generally that can be from a bad head gasket, valve stem seals, rings/oil rings, crank case breather setup and that sort of thing.  I'd have a look at the intake and see if the airbox, carb and/or intake port show signs of oil going in that way.  If not, then its most likely rings, HG or valve stem seals.  Of those, it seems unlikely that rings would go from good to not good so quickly. Anyway, I'm sure someone much more up on 2v motors will be along shortly with better advice.

good luck!

[Howie]

Yep, oil fouled.  If you are still on a college budget you could see how long the new plug lasts and carry a spare or two with you  Also, check cheap fixes first.  Overfilling crankcase?  Most Ducs have a level between full and add that makes them happy.  Constant topping up can send oil into the air box.  Bad breather valve.  Doesn't close?  Oil in airbox.  Doesn't open?  Excessive crankcase pressure.

And yeah, a quart light won't kill it.