Hi Chaps, I’m fitting a new chain but I’ve noticed the front drive cog has 3-4mm movement (back & forth) is this normal ?.
(the shaft and cog are not the full spline type, they have 6 wide splines).
Edd.

Mine has a wiggle also....seems to work fine , I've added a thin washer (shim) ,probably wasn't needed. no excessive wear on spline or sprocket ....mike

Hi Mike, Did you put your shim at the front or back or the cog ?
Edd.

Mine has that also and you can see a bit of wear on the shaft. I plan to sacrifice a new sprocket and weld two together then turn the teeth off the inside one. May have to face a bit off the thickness also but I plan to make as wide a "single" sprocket I can. Will need to leave a little room for in and out movement. It's either that or replace the shaft with a newer 660 one if it even fits. I have to do the same with my Honda, each sprocket change I'll need to buy 2 sprockets, but it'll save the saft for quite a bit longer.

Someone said that a DR650 sprocket fits,it has about a 10mm wide centre section.
Regards Eric

There is a groove around the shaft (one inch in) this is where the retaining plate Is turned to line up the fixing two bolts with the sprocket.
I’m wondering if;
a) The Groove on the shaft has worn.
b) The retaining plate splines have worn
c) I suppose both could be worn

I’ve never noticed this “play” when running, so do I follow the old phrase,
If it isn’t broke, don’t fix it.
Edd.

I'm going to check out the dr650 sprocket now. Otherwise just ride on. Mike

If the DR sprocket does fit you'll need the retainer plate also, they use three bolts instead of 2. As far as being thicker, I can't say, the ones I saw weren't any thicker(unless factory ones are), I looked at Sunstar and JT ,both were the same as what I get for the XT. I see Suzuki also went though having the 6 big splines and then updating the newer ones to the 18 smaller ones due to shafts wearing out like Yamaha and Honda's did.

The DR750 sprocket has the 10mm centre section. Use a dr650 retainer or a pair of circlips. Factory DR650 sprockets from 1996 on are 525 pitch. Pre 1996 650's and the 750/800 had 520.