Hi,

wld anyone know the code of the pro mainbearings? And wld they differ within years or did they stay the same all years?

Thanks in advance,

George

ps: reason i ask, i recvd a different mainbearing from dealer as was in it. So are there probably more codes that fit?

I've got an old bearing that came out of my 05 pro 250cc.

one side says MT 280412006, the other side says ST 5225.

hope it helps.

Sorry Mikee,

i mend the code like 6205 c4 ...... or c3.... and more if there is.

They gave me a 6205c4 bearing from skf explorer. A nine balls variant.

The former bearing was a 6205 c4 without explorer on the side and was a 8 balls.

The first one, from the dealer, did not fit over the cranktap because of the bigger inner rim.

So there are different versions of the 6205 c4/c3 bearings ?!

edit: i changed the 6305 into 6205.

I see that in the manual of 2003 the nbr listed for the mainbearings is\M01216002/2, 6205 ETN9 2x

Can we assume that the bearings changed tru the years?

Edited October 6, 200817 yr by gasgas

Hi gasgas,

On the PRO's through to 04, the main bearings were conventional type with separate crank seals, plus a sleeve that fitted over the crankshaft, From 2005, GG introduced new main bearings that have a wider outer race, this was to accommodate an integral crankshaft oil seal to make servicing easier - it does! The sleeves were no longer needed.

Also, the new bearing has the old P/N and is machined to take an O ring on it's outer diameter and another (25mm dia) O ring on it's ID.

It is best to buy the later GG supplied bearings as these are made for GG and probably not available through a bearing supplier.

The newer bearings fit the older motors too (though you need to leave out the sleeves).

Remember that you still have an extra (teflon) oil seal to fit in the mag side.

The newer bearings are a very tight fit, I needed lots of heat from a heat gun before they would move freely from their housings.

When re-fitting, there is a drain hole in the LHS crankcase bearing housing that must line up with the drain hole in the new bearing, this allows gearbox oil to flow freely through the LHS bearing. The RHS does not have any alignment issues.

When buying the bearings, you must request the bearing, oil seal, outer O ring, inner O ring - all for one bearing. (Teflon seal for LHS is extra)

Heat up the crankcase to assemble bearing, leave bearing in the freezer for an hour so that the bearing just drops in to position when fitting, make sure the oil bleed hole is aligned.

Bye, PeterB.

Peter, Thanks for the info.

With my 2002 crank, i can remove the sleeves for the cranktaps? I always thought they were one solid piece with the crank ?!

I already discovered that i need the 6205 ETN9 bearing since these have a smaller innerring and fits the sleeves of the crank.

Great help

Thanks

George

Hi George,

You can remove the sleeves from the ends of the 02 crank, and use the later sealed bearings if you wish.

Bye, PeterB.