noise from 01 426

[29-keith-29]

i just picked up an 01 426 and the guy i bought it from said it needs a top end its hard to turn over and makes a kind of grinding noise form the motor i checked the oil and it took more than a quart till it was full up to the line on the dipstick my question is do u think its realy the top end or could it be somthing else any tips on where to start would be great

[MichiganMXer]

Well I'm no wrech monkey.. but my 01 has the original top end. If its hard to turn over then the compression might still be good and i question the need for a new top end? Is the exhause smokey? A slight tinge of black is normal when you blip the throttle.

Oh and when you notice the header turn red at dusk its completely normal.

[29-keith-29]

ok so i got the head off my bike and the walls of the cylender arnt scored or anything it turns over easyer but i dont think its turning over the way it shoul but then again im use to 2 strokes im starting to think the problem may be in the bottom end also is it posible for the timeing chain to get way to tight and make it very hard to turn over?

[glamisrob]

Are you doing the start-up procedure correctly? If not, it would be very hard to turn over. Before tearing into the motor, I would make sure your valves are in spec and that you are following the start-up procedure. I have had my '01 since new and have never had to have a new top or bottom end.

[todds924]

ok so i got the head off my bike and the walls of the cylender arnt scored or anything it turns over easyer but i dont think its turning over the way it shoul but then again im use to 2 strokes im starting to think the problem may be in the bottom end also is it posible for the timeing chain to get way to tight and make it very hard to turn over?

Did this thing run at all before you tore it apart? It would have been nice to hear it first. You say it turned over easier with the head off? Look real careful at the cam holders for scoring. I just had a look at a wr 450 that would hardly turn over because of this.

[29-keith-29]

found out its the lower end main crank bearing its all blue the kid i bought it from most likley ran it out of oil ? idiot at least i know what im dealing with now

[grayracer513]

found out its the lower end main crank bearing its all blue the kid i bought it from most likley ran it out of oil ? idiot at least i know what im dealing with now

The main bearings are the ones the crankshaft spins on. If you mean that the crankshaft flywheels are blue at the point where the crank pin goes into them, that's normal; it's a product of the manufacturing process. If the rod bearing actually gets that hot, the rod will be blackened at the big end.

This is not to say that there isn't something wrong with your rod bearing, only that the bluing on the crank doesn't indicate anything bad.

[29-keith-29]

The main bearings are the ones the crankshaft spins on. If you mean that the crankshaft flywheels are blue at the point where the crank pin goes into them, that's normal; it's a product of the manufacturing process. If the rod bearing actually gets that hot, the rod will be blackened at the big end.

This is not to say that there isn't something wrong with your rod bearing, only that the bluing on the crank doesn't indicate anything bad.

its the one where the conecting rod sits on its acualy siezed up it turns but not very easily

[crazyal426]

New oem crank is about $300. A little cheaper if you shop around. Luke's Racing in PA might be a good choice for you being a little closer to you. He can also hook you up with any other parts you need. Buy a good manual too.

Good luck!