2001 Yamaha 90 2 stroke top bearing noise

jfalco

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I have a 2001yamaha tlrz90 I had rebuilt in 2023. There has always been a noise coming from the engine after the rebuild. The rebuilder moved out of state after he finished the job ( comments should get good now). I pulled the flywheel today and noticed little play in the crankshaft at the top bearing. Can I replace the top bearing and seal from the top of motor or does it have to be disassembled to replace the bearing???
 

99yam40

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I would think the case has to be split, but your service manual should give the info needed
 

Mc Tool

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How much play do you have . These things have ball bearings and they do have a bit of clearance...like a couple of thou ....the sort of clearance you may feel if you give it a wobble but if you can see movement its probly to much , and its an engine apart job to replace the bearing.
 

racerone

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Dec 28, 2013
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Looks like a needle bearing to me.----And the crankshaft surface is part of the bearing.----Needles run on the crank.----Was that bearing carefully located on the dowel when you assembled this motor ?
 

99yam40

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looks like it is a needle roller bearing on that top one ,so should not be a pressed on bearing.
may have to send off crank to be rebuilt or buy new.

only one with the answer would be someone that rebuilds the motors
 

jfalco

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Hey guys thanks for the help. There is slight play at the flywheel that I can feel but not enough to be seen. The noise I’m hearing doesn’t sound like a bearing noise it’s almost a clicking noise and I ran the boat all last year and the noise didn’t get any louder . I’m thinking it may be something else. The mechanic I brought it to didn’t get into it and told me it could be the bearing. He didn’t even remove the flywheel. He told me he don’t work on old motors . It almost sounds like when I was young I used to clamp a baseball card on my bicycle wheels so it would sound like a motor.
 

racerone

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Post #1 says you want to replace the bearing.-----Now you say it is a clicking noise and not a bearing ????
 

jfalco

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Mechanic mentioned the bearing because I f the slight play if you push on the flywheel. It’s mentioned here that it’s normal for couple thousandths of play so I’m thinking it’s something else. Like I said I don’t think it’s a bearing noise
 

99yam40

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I have read a fuel pump can make a clicking noise if air gets into the pump instead of solid fuel
 
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