Cam bearings

[pahako]

So I need to replace the 2 cam bearings on the left side of the engine. There is definite "play" in them. I believe this is why I have had frequent leaks from there, even after I replace the seal on that side, and more top end noise than normal. There is no movement at all on the right side and I have never had a leak on the right either. I realize that conventional wisdom would say if you have to replace one, you should replace them all, but at $17.00 each, they are not cheap. Just wondered what anyone else thought. One more question. Dip in oil, or pack with grease?

Thanks

 

[XSLeo]

I would also suggest replacing them all while your doing it. If the one side is bad now, how long before the other side goes bad? The extra two bearings would be $34, how much would it cost to replace them in 6 months or a year.
As far as pre-lubing I would just dip in oil. They run in the engine oil. A light grease that would wash out as fresh oil gets pumped through them would also work.
Leo

 

[TwoManyXS1Bs]

Those bearings have the special "C3" clearance, which makes them a bit looser than regular bearings, presumably to tolerate particulates in the oil. Prudence and shop policy would call for replacing all 4. The cheepskate shadetree mechanic in me would consider 2 methods, depending on bearing condition.

1 - Examine and sort the bearings by looseness, 1= tightest, 4= loosest. Assuming that the bearings don't grind and are reusable, assemble on camshaft, left to right, ordered 1, 3, 4, 2.

2 - Get 2 new bearings, assemble as in #1, ordered (new), 1, 2, (new).

 

[willis]

I am about to install new cam bearings too. Curious about positioning them on the cam. Do they get placed all the way inboard on the cam ? Not sure how much clearance is needed for the seal.

 

[grizld1]

Your answer is in both aftermarket and factory service manuals. You can download the factory manual free at http://www.biker.net.

 

[retiredgentleman]

I am about to install new cam bearings too. Curious about positioning them on the cam. Do they get placed all the way inboard on the cam ? Not sure how much clearance is needed for the seal.

Yes, the bearings must be placed as far inboard as possible, because the oil seals barely have enough exposed surface area on the camshaft. Make sure to have the camshaft centred, so that there is an equal amount of camshaft exposed on each end.

Another tip: If replacing the camshaft oil seals, don't buy Mikesxs.com oil seals. I found the so called "Performance" triple lip seals are 7 mm wide which is just too wide for the space available. They only lasted one season for me, before one seal started to leak oil.As usual, Mikesxs parts don't fit or are sub standard.

I've now bought the oil seals from www.boats.net. They are the Yamaha OEM part, and cheaper also. They are 6 mm wide, single lip, and will fit much better.

 

[willis]

Thanks RG

 

[pahako]

Yes, the bearings must be placed as far inboard as possible, because the oil seals barely have enough exposed surface area on the camshaft. Make sure to have the camshaft centred, so that there is an equal amount of camshaft exposed on each end.

Another tip: If replacing the camshaft oil seals, don't buy Mikesxs.com oil seals. I found the so called "Performance" triple lip seals are 7 mm wide which is just too wide for the space available. They only lasted one season for me, before one seal started to leak oil.As usual, Mikesxs parts don't fit or are sub standard.

I've now bought the oil seals from www.boats.net. They are the Yamaha OEM part, and cheaper also. They are 6 mm wide, single lip, and will fit much better.

I wish I new about this sight before I recently spent so much money at Mikes. A lot of the things I needed are less expensive, but some things I noticed are quite a bit more expensive too. Pays to shop around.

 

[retiredgentleman]

I wish I new about this sight before I recently spent so much money at Mikes. A lot of the things I needed are less expensive, but some things I noticed are quite a bit more expensive too. Pays to shop around.

Its always wise to spend time searching and reading the threads on this site, before ordering any parts,especially from Mikesxs.com. I've been burnt so many times from Mikesxs or the Canadian equivalent, that they have become a parts source only as a very last choice, if I can't find parts otherwise. Yamaha OEM is always first choice, but of course they are not always available anymore.