Connecting Rod bearing failure

Lower rod bearing let go and blew throughout the bottom end. 426 was new in February/00 and had regular oil changes. Yamaha has told me sorry about your luck.. I'm looking for more ppl that have had the same thing happen cuz they say this is a flook.. I think this is crap.. 1300 dollars in parts later.. including crank assembly cuz the bearing skored the crank due to the fact there is no sleave on the crank .. oil pump, piston, all gaskets.. o-rings ..etc..

This sucks.. I love the bike though.. but wondering if I should sell the thing if this is a regular problem for the bike.

email me if you can cuz I forget to check the forum sometimes..

THank you ..

Jody Maynard

Ontario, Canada

$1300 bummer but that would be a cool project if it weren't so expensive. No sleeve on the crank?? hmmm There is a guy here by the way that will prolly join you in your crusade and another who wants to start a, he will prolly be in with you. Good luck with your quest and sorry to hear about your bike... Mine is still good, starting to think it's as good as an old XR. Let the whining commence... :)


From what my mech told me most bikes have a collar or sleve where the connecting rod bearing rides on the crank.. this doesn't exist on the 426 so.. it scored the crank.. and the cylinder and mangled the oil pump..etc


Did you ask your mechanic what, in his opinion, caused the bearing to fail? Maybe something happened to the oil supply to the bottom end. A bearing without good oil pressure won’t last long (duh!).

If it ruined your oil pump it must have really made a mess in there.

You have my sympathy (I’m sure you feel ALLLL better now :) )

I haven’t heard of any crank, rod or bearing problems with the 426 (until now that is).

I recently split the cases on my 426, its not hard to do at all, but you do need a special tool to R&R the crank out of the left case half. I’m sure the total bill would be half (or less) if you did the work yourself. Just a thought…

ontario rider

what a shame you didn't talk BEFORE you had the work done. i would think that the crank journal had only a thin case hardening & they couldn't be arsed to get it welded, ground & retreated.

i just hope all the oil galleries are clear. keep changing oil & filter regularly. trouble is, it's like when you have your house burgled-it just ain't the same anymore is it?

good luck this time around though.


My friend is a mechanic at the big shop and did it at home so the bill won't kill me on labour. That part about rebuilding the crank kinda scares me though after spending 700 bucks in parts for the rest of the stuff. Wanna play I guess you have to pay.. hopefully this isn't a regular thing for this bike. He had to press the crank appart I guess to spearate it to get the rod out. Yah it made a HUGE mess including scoring the cylinder but he though a cylinder hone would fix this. I'm just glad to hear nobody else is having this problem.

Does anyone else know if the 2001 front pipe makes oil filter removal any easier? And if it will fit on a 2000 or should I just go aftermarket front pipe..? Hastle to remove filter around pipe.

THanks for the input.


Ontario- the 2001 head pipe does not have to be removed to change the oil filter, that is one of the model year changes...


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