426 engine noise after rebuild

2 replies to this topic
  • amitx

Posted June 10, 2010 - 01:00 AM


i didnt get help in the wr forum, so maybe here some one know about it

my friend blow is motor cause the 4 gear failure, he didnt get much luck
the gear broke down while raiding and got stuck in the crankshaft while spinning, that cause the rod to disconnect from the piston after that the broken rod blow the piston cylinder and the crank case.
let say almost the all engine, and it wasn't the first time with the bed luck with that gear(also 4 or 5 gear that broke down).
Posted Image

Uploaded with ImageShack.us

any way he bought a used crankcase from ebay and it was like new, we checked the bearing and they were good with out making any nose or free play.
after installing the engine it makes some noise from the clutch area.

so i opened the clutch small cover and we notice that it all look dry there, the pump is working (we check the banjo bolt and it's getting oil).
i search at the manual about that and all i saw is to check the banjo bolt, and if there is no oil so you need to check the oil pump oil line blockage or something like that( yhaa really this was very helpful).

so how do i really know that the oil pump is working good?
why the oil didn't rich to the clutch area(it was dry and clean like i assemble it)?
how can i check the oil hight in the engine?
i think that the bearing is not getting oil so that is where the noise from.

sorry that i was too long:banghead: didnt plan it to be that long.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted June 10, 2010 - 08:31 AM


There is not a very large amount of oil delivered to the clutch in this system, but there are a couple of things you can do to check it.

  • Remove the front sprocket and the steel collar behind that that the seal runs against. Start the engine. Oil should be pumped out past the seal.
  • Remove the clutch cover, pressure plate, all clutch plates, and the clutch push rod. Be sure there are no loose parts in the clutch assembly. Stay clear of the clutch, and start the engine. Oil should be pumped from the main shaft center.
If neither of these things will happen, the oil transfer tube may have been left out of the engine when it was assembled.

  • amitx

Posted June 10, 2010 - 10:23 AM


thanks for the info, we start the engine in the first time without the front sprocket and we did have a leak from there, but i will check again to be sure,
it looks like the clutch dont get the oil so i will check that,
i told my friend to start the engine without the small clutch cover but i didn't think about running it without noting in the clutch :thumbsup:

Related Content


Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

Need help by Goforaride

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  68 replies

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  106 replies

2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.