os 91 surpass cam bearing removal
 

Wondering if anybody knows how to remove thebearing from an OS 91 surpass cam cover?</p>

RE: os 91 surpass cam bearing removal
 

I'm sure there are a lot of different ways to do it, but I'd do it the same way my Dad taught me to remove clutch pilot bushings on cars. Pack the hole with some grease, and find a drill shank that is as close to the IDof the bearing as possible. (I use transfer punches but a drill will work). Put the shank of the drill in the ID of the bearing and tap on the drill with a piece of wood or something similar (so you don't ruin the drill).

The pressure ought to pop it out. Might need a little heat first, which might loosen it up.

Good luck!

Mark

RE: os 91 surpass cam bearing removal
 

<![if gte mso 9]><xml><o:officedocumentsettings><o:allowpng></o:allowpng></o:officedocumentsettings></xml><![endif]><div>Ijust changed my OS 91 cam bearings a few weeks ago. Iused a method similar to the grease method.

I selected the largest wood dowel that would fit inside the center bearing hole of the bearing, about 1/8 inch. I then took an old candle, and shaved wax and placed it inside the bearing center hole, and packed with the dowel and a light hammer. Keep repeating, and you will notice the bearing starting to rise out of the cup. It required no heat, and about 12 repeats of packing with wax. The wax moves behind the bearing and exerts hydraulic pressure on the backside of the bearing.
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RE: os 91 surpass cam bearing removal
 

An auto mechanic show me how he could remove a bearing using toilet paper instead.

RE: os 91 surpass cam bearing removal
 

Thanks for the input, will give it try with the wax method.</p>

RE: os 91 surpass cam bearing removal
 

This week I helped a friend remove the cam bearings from a Magnum 91 4-stroke, which is essentially a copy of the OS 91. The bearings in the cam cover came out with heat only, simply by heating them up, placing the assembly inside a 5/8" socket and tapping on wood.

The cam bearing in the crankcase was another story. I tried the grease trick and it was not viscous enough (too thin) and simply came through the bearing. Then i tried the wax tricked and it worked! So thanks for the wax tip! I filled the ID of the bearing with wax chips and used a transfer punch that was as close to the ID of the bearing and packed the wax in by gently tapping. By refilling the ID with wax as I worked it in, eventually the bearing popped out.

Hope this helps!

Mark

OS-91 Surpass Bearing Removal
 

Just finished a successful removal of the camshaft bearings using the "shaved wax method". Heating with the torch did not work so I
used the wax idea mentioned by others and the bearings popped out as expected.

Thanks to whoever was the guy that tried this the first time.

Richard

I have found that the cam bearings rarely are bad enough to actually need changing. The crank bearings can be completely rusted and ruined but the cam bearing can often be saved with a lot of oil flushing and rinsing.

Hi w8ye. You are absolutely correct.
My main bearing was rusted badly and the front bearing was completely destroyed.
I did replace my cam bearings while l had things opened up, but they were actually in
pretty good shape.

Thanks for your comment.

Richard

I've done a few OS and Magnum four strokes in my time, I only had one that needed the cam bearings too.