I'd agree with Marcm, the rod end looks to be a little too galled and need honing but would probably be out of spec. Get the 3AJ pump definately, the extra oil those pumps provide goes entirely to the topend, right where these motors need it.

I wouldn't go by looks, mine looked similar, and was only .001" clearance! :)

I need to buy a micrometer for inside diameters... But the con rod end looks bad and also good at the same time: the light scoring is there, but mostly in the middle/maybe right, but on both sides I can see the polishing (honing) marks. First I think I'll wait for the piston kit to arrive and then check the clearance between the new pin and con rod. I'll buy new if in need...

The oil pump: 3AJ is a 600Z Tenere, right? Well, my engine looks to be THAT engine, haha! Is there a code on the oil pump so that I would be certain it's the right one?

Here's the pictures, maybe not very informative, but...:

http://imageshack.com/a/img84/7821/dscn7352y.jpg
http://imageshack.com/a/img831/6761/dscn8350.jpg

Although that doesn't make much difference, but I measured the old piston pin.

In the places it doesn't wear it's exactly 22.000mm. At the con rod it's ~21.985mm, and at both ends (piston wear places) ~21.990mm.

The manual says: 21.991~22.000mm.

The worst would be if it hadvtighter and looser spots , it would cause all the pressure put on smaller areas. I've run a cylinder hone with very fine stones in it to just polish off the high spots(usually galled material).

Your motor should have the good pump, it will have the letters 3AJ cast into it.

Hi I have just bored my 91 600e out from 95mm to 97mm and the standard head gasket was fine. I ported out the head heaps and had cam modified to a stage two yossie grind. I split the two piece steel base gasket down to one layer to lower the barrel and raise the comp. It has lots more low down talk and revs better ! The REV light on the dash even pops up from time to time :mchappy: Your bike looks good :thumbup1: but after fitting an exhaust like that you will need to make a brace to support the seat as the old muffler was a support for the sub frame. :funmeteryes:

P/S after reading jjriders comment about the offset piston pin I checked my old XT piston and it definitely has the offset pin ! its there to counterbalance the thrust and my aftermarket piston had it to. bier

Are you sure exhaust makes support? Have been riding for 7years with aftermarked and no problems.

Ok, no big fat lady on this then! What difference did they make on the next model for not having this support?

On the 96-up models theres a piece of frame from around the right rear footpeg, that goes up and supports the "subframe"

Ok i see, well i dont think anyone have to worry. Have been riding with alot of weight all years and no bending on the frame.

I see you are running 660 carbs are they both vacuum carbs ? was it easy to fit them ? ( do I need 660 manifolds to fit to the head ) and the big question !! do they make a big improvement ??? :confused1: I wondering if it worth the money ? Thanks.

Frame flex due to aftermarket exhaust: haven't noticed any. However the rear subframe will be cut off someday once I do an YZ/WR (or similar) rear end swap.

Carbs: everything is in my bike's thread. It's a CV (constant velocity) carbs.
They do fit in the original XT's intake boots, you just need to trim them down a bit (1-2mm) where the boots touch the carb and doesn't let it "deep enough" in the boots. Also you need different choke, different air filter...
After everything bought and shipped the conversion cost me around 400Euros.
But the improvements were... Quite significant. After the first ride I came back all shaking with excitement and with a huge grin on my face :biggrin:

ya they are now that I looked , I knew they were different than the raptor/grizzlies though, just thought the XT's were the ones that I had that were centered. Raptor/Grizzlies are .164" offset , the XT's are .079" so still not meant to be swapped.

jjrider, I would understand that if it was just the seller, listing a Grizzly pistons and claiming it will fit an XT, but is the manufacturer lying too?

When checking the part number I found this on the Wiseco web page:

4607M09800 Product Detail Information - Wiseco Piston Inc.

Check "Applications" section. It says:


Yamaha YFM600 Grizzly (1998 - 2001)
Yamaha SRX600 (1984 - 1996)
Yamaha XT600 (1984 - 1996)
Yamaha XTZ 600 Tenere (1984 - 1996)

I can measure the piston once I receive it.