WB1, noise, lossing power. problem

Aug 20, 2018

I have a WB1 -94
61 X engine
Mikuni super BN 46
Airfilter Blowsion
Boyseen carbon reeds
Nynja C4 pipe
701 rear exhustpipe
MSD coil
MSD Enhanser
TDR water box
solas 14 / 18 prop
SBT wearring
Milled head.
170 / 175 psi

Last year it started to do a short metalic hight pitch nose. Sametimes / often at WOT and shopy water. Sometimes in a holeshot.

Have tryed the following stuff:
The oem wearring had swollod and I changet it to SBT plastic werring.
Rebuild the midshaft with new bearings and seals
Rebuild the pump with new bearings and seals
Lowerd the RPM limit to 7400 rpm
Installed dual cooling

Last ride before i teard the engine apart i moniterd the rpm and speed.

Cold 6400 rpm and 41 knot / 47 mph
Then after 2-3 min it dropt to 5500 rpm and 36 knot / 41 mph
And in the end dropt to 5250 rpm, didnt get a speed. At this time a nose came often.

No vaccum in the fueltank.
Tryed 1/4 turn ritcher, worse speed, stil the nose.

Wen i came back I notice the engine pto was very hot, to hot to hold your hand to.

Now I have teard to engine apart and have maby found something?

The seal surface has a been very hot and changes color.

Is this from the seal o bearing? Have anybody have this kind of problem before?

It starts to get expensive and want to ride!!!


Or is it something else?

With best regards / Christian
May 16, 2017
Detroit metro
From your video that crank main bearing looks ok. Side to side seems fine and it spins freely. Is your pto aligned to your midshaft coupler correctly? Perhaps the alignment is way off causing too much friction in that joint?
Nov 3, 2016
Northern michigan
That bearing is toast. There shouldn't be any noise coming from it and there is movement. If the others are making noise replace the crank. If its just that one replace it. When you put it back in align/shim the engine.
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