Just got in the third 40 Tooth rear sprocket today. One primary drive on Afco alloy

All of the ones I have are listed 87-89, but none fit over the four nubs on the spocket hub for some reason.

What gives are the 87 different to the later modles, Mine is a 88 the hub apears stock oem cast steel.

I must be missing something? 

Yup im going from the outside like most other quads I own and seen.

Its the four inner nubs, used to further index the sprocket from the inside diameter bore

bascly the ID of all the sprockes i got so far are too small, the bolt holes line up fine just stands off a bit causing a super poor fit that would bend the sprocket.

 

Yup the machine is minty and mostly stock, i bought the lt500r already 95 % restored last year and never noticed a problem. Till i saw there was a bow in the what was already a new sprocket from uneven pressure.

Since then i ordered one from RMATV primary drive, and one alloy one off ebay, affco or something like that.

The hub is a ruff casted maybe the guy who restored it borrowed it off another machine like a 250r or something weird.

The orginal sprocket got four square rub marks on it, form not fitting right id say its 4-5mm off total 2.5mm of each corner.

I cant seem to fine any used hubs on ebay, other that one crusty one, so I will just have to fork out more $$$ for a new OEM one maybe. Just hope it fixes my problem I will take a pic this weekend