Sportster trans gears in KH question

[thefrenchowl]

How to ruin a good clutch?

Make it wet...

Patrick

[55panman]

Yeah Patrick, may agree. I ran a dry clutch in my 77 XR750 for 6 years racing and it was the clutch in it when I got it. Lota races on it and never a problem. But I'm putting together a '75 XR750 and it has a chipped 20 tooth clutch gear and the only replacement I have is a shorter wet clutch, clutch gear. And you know how hard old XR parts are to find. Almost as hard as KR parts. You don't happen to have an extra clutch gear? 19 or 20 tooth? Ron

[JerrryR]

Which 20 tooth gear is this one? Is it what you need.
JerryR

Clutch Gear 20 Tooth, 1.jpg (87.64 KiB) Viewed 7211 times

Clutch Gear 20 Tooth, 2.jpg (52.47 KiB) Viewed 7211 times

[thefrenchowl]

Hi Ron,

I do know from the 1990 XR parts book that XR has different lengths of clutch gear depending on years, bell and hub diff widths, steel or alloy, but never seen the parts here in GB.

The long (shown on bottom) clutch gear is for the steel components which are basically 52/70 XL/XLH/CH and easy to find:

XR different clutches

1.jpg (389.96 KiB) Viewed 7197 times

Which means both set ups can deffo be used with dry clutches??? (they are both shown with the derby tin cover)

But the bottom set up can only use the tin primary cover, while top can use both cast alloy or tin primary cover.

Patrick

[Kurt]

After mulling over the info you guys have provided, plus sitting with the parts manuals and a glass(es) of wine I have decided to just use the trans I have. I will change out the clutch gear and mainshaft (probably 37448-71 clutch gear and 355046-71A mainshaft). The reasons are:
1) There was not much interest in my trans on E-Bay or Craigslist.
2) Clutch gears and mainshafts are not too pricey.
3) I just found out that the primary drive/clutch that came with the basket case is also early '70's so I should be able to use those on the KH too. (Unless
corrected by someone! I think there is an issue with the primary chain length, but I have to research it.))
4) No better time to get intimate with a transmission than during lock-down. (Computers and transmission have alway seemed to be 50% voodoo anyway. Good
time to get over that, with transmissions at least.

Stay healthy!!!!