Rebuilt yfz now I need help.

[CMR250R]

I just rebuilt a 2004 yfz for a friend of mine, the crank seized, so I bought a crank, piston kit, brand new cylinder, main crank bearings, and a moose gasket kit. Everything was stock yamaha parts except the gaskets. The bike is also totally stock. The rebuild went well everything checked out, except when I went to check the oil in the reservoir tank the dipstick was dry. I put in 1.5 qts yamalube 10-30 in the reservoir and .5 qt in the motor like the manual says. Then I started the bike and let it run for like 5-10 min shut it down and I let it sit for like 30 seconds, I checked it and there was nothing on the dipstick... The motor sounds really great, no noise, no smoke, oil comes out the top banjo bolt in the cylinder if you loosen it -so it has oil getting to the top end. It just isn't going back into the reservoir. I took the top line off the res and I put my finger over the end to see if it was building pressure and it did but it kind of felt weak and a slow stream would flow back into the tank. During the rebuild I cleaned and blew out all the oil lines/pasageways. Now I'm totally stumped and really need help. Thanks in advance for any help you guys can give.

[Splatter Matter]

on the oil thank itself did you take the bottom hose off. if not do that there is a screen filter that might be blocked.

[KH426]

2 QT. for a oil change it will be more for a rebuild.

[JR3]

Originally posted by KH426
2 QT. for a oil change it will be more for a rebuild.

yea deff justa dd more oil start it again and check it u should be fine . and yea u should check the screen every couple of oil changes i remeber the first time i checked mine i was like :eek2:

[CMR250R]

I cleaned the screen and also added oil probly like .3 qt so now it would have like 2.3 qts total still nothing on the dipstick. I tried to blow air threw the return line and it would only let me blow air in the direction of flow. I started the bike with the top line off over the hole to see what was coming through it and barely any oil was coming out. I'm thinking that my next move is going to be to take the clutch cover back off and inspect the oil pump. The thing is that it is definately getting oil to the top end and the motor sounds great but the oil isn't returning to the bottle.

[440ex342]

first why did the bike blow check to make sure it is pumping oil i know they will take 2 qts. without changing the filter . also do you have the lines right on the motor.

[CMR250R]

Thats the thing I'm not really sure why the bike blew the crank rod bearing blew on it. Also cant the lines only go on one way? I"m almost positive that they are right.

[speedy]

How do u guys get to the screen ??

[CMR250R]

the screen is on the bottom line inside the oil tank. You have to remove the bottom oil line on the oil reservoir then you will see the screen.