oil leaking out of the left side of engine

Recently purchased a use wr250r with 1300 miles but not running because of fuel pump failure. Bought new oem replacement fuel pump and installed it, bike turned on nicely. Let it run for a few minutes and then noticed oil leaking out of the left side of the case where the top and the bottom half meet, seal. Is this bad? Thought it was comming from the oil screw check bolt but doesnt seem to be.

Just take off the cover and inspect things. It may be as simple as a crease or break in the gasket.

He said it is leaking between top and bottom halves. I take it he is talking about the base gasket. Ive changed lots of gaskets on two strokes but never on a four stroke.

mcdoudlehopper wrote:

   He said it is leaking between top and bottom halves. I take it he is talking about the base gasket. Ive changed lots of gaskets on two strokes but never on a four stroke.  

Yes seems to be the base gasket... I presume the bottom half is the crank case? Leaking at the seal where the crank case meets the top head. I have only worked on my two stroke 72cc moped. This bike had been sitting for over a year so its highly probable that the elements broke down that gasket seal, really dont know for sure. I thought these bikes were reliable? I conveniently misplaced the owners manual also. Not sure if I trust myself with this job, probably will take it to the dealership since I already paid for $100 trouble shooting fee from them and they said they would honor the fee for 6 months if anything else was wrong.

When pulling the jug off of the piston, there is timing chains and crap to deal with. If it isn't 100% you could throw a valve in before piston stroke which would be catastrophic to your engine so I would seek professional help. wouldn't be a big deal for a Yamaha tech to deal with vs your frustrations and pocketbook. You may be able to save some money by maybe pulling your engine and bringing it in vs bringing the whole bike. Contact your local professionals and get some advise.

Whooo...! Dodged a bullet there, turns out it's the gasket on the stator / crankcase cover where the oil is leaking from. And it may be from the dealership techs who recently replace the stator under recall. I really don't trust that god forsaken dealership...some shady mofos. Gonna be writing an email to yamaha on account of all the bs I had to go thru, and money they robbed from me.

SWEET! glad you got her figured out. Now go ride! LOL

" SWEET! glad you got her figured out. Now go ride! LOL"

Can't wait!

Just went for a spin around town at 42 deg. Couldn't wait any longer and supposed to snow thurs and sat

I took mine for a test spin today and had a lot of fun riding it. Keep in mine this is the first time I stepped on a motorcycle since I crashed one the first time riding a friends dirt bike. Since then I have listened to my moms advice and warning about it being too dangerous to get one. about a year ago I bought my first Kymco cobra 50 cc moped slightly modified by a mechanic friend,. It's a cool little ped with beefier shocks and enduro styling. I been messing around on it and tunning it up even more and then I thought man I'm putting a lot of money into this thing just to go 55 or whatever and I was getting confident enough in my skill to avoid danger, so I decided to get a moto cycle next. Which brings me here now at the age of 30, and I was able to step ride onto the wrr no problem and blast off. I did stall it once on a steep hill tho. But I still have more questions about this bike. Why does it smell kind of rubbery out the exhaust. It's been sitting for a year or more. Also I noticed the new fuel pump sound like a light whirring sound...never goes off. Seriously eady to ride don't get why people complain a lot.