Straight Shaft KT-100 clutch...

Ted Hamilton

Helmet Painter / Racer
I've come into posession of a KT-100 old-style straight shaft, inboard PTO. (driver's side PTO with standard right-sidewinder.) I'd like to run this with a minimum of PTO weight, and as reliable as possible, no jackshaft. Would the best option be to treat it like a JICA and get a 3/4" bore single disk clutch with low engagement?
This will be for local LTO dirt. It will be getting the Steve O'Hara easy tune treatment so it will idle nice and low too...
 
The problem is getting a small enough gear on the 3/4 shaft. Most just change the PTO to a tapered one. Does it have the 3rd bearing in the coil cover?
 
We used burco 9 teeth 3 shoes worked great thinking I may have horstman wet disk for a straight shaft
 
I'll have to see what I have for #35 3/4" drivers and 8mm belt drivers.... I may be able to work something out for direct drive! :) What's a common southeast overall ratio? 19:53 j/s to 20:66 secondary? That's what, about 9.5 ratio? I ran DD on asphalt at 10:85... Be interesting to hear. I can get a BMI jackshaft if I have to, unless someone has a Buller laying around they want to part with...
 
Sold my project motorcycle, so now I can afford the jackshaft. Guess I'll go "standard" for that. :) Savannah, you mean Roebling Road? I'll be there with LO206. if I can talk my boss into letting me have Friday off...

Ted, unless you just want to race Rainman around North Carolina forget direct drive lol Chuck (ps Savannah 3/6 to3/8 be. there).
 
Shaft could be turned down to 5/8". Clutch on jack shaft is interesting but I have to wonder about a price comparison on getting a tapered shaft/engine clutch set up.
 
No simple answer for this .
A sleeve to bring it up too 3/4 " with a normal clutch and custom key .
Stub shaft is too much strain on crank , plus super wide .
 
I'll have to see what I have for #35 3/4" drivers and 8mm belt drivers.... I may be able to work something out for direct drive! :) What's a common southeast overall ratio? 19:53 j/s to 20:66 secondary? That's what, about 9.5 ratio? I ran DD on asphalt at 10:85... Be interesting to hear. I can get a BMI jackshaft if I have to, unless someone has a Buller laying around they want to part with...
gear ratios 3.jpg
 
I should post a pic... IT's been used with a 3/4" clutch before, so I'm not sure if it's a custom deal or what, but it's "inboard" compared to a normal KT. I'll put a 3/4" clutch on there tomorrow and see if it's got some slop or if it's a good fit. I'm inclined to find a single disc and run at a low engagement, kind of like a TaG clutch or JJCA clutch, and use it on my vintage kart sometimes. (It's period correct for that...) Pics tomorrow.
 
Get a hold of Jack Lehman at Kart O Rama or Terry Ives. They might be able to sort you the correct DXL hub for a straight shaft KT. They are out there. I saw a couple last summer. Personally I'd just toss a used bottom located crank in it and use modern clutches. They are dirt cheap if you don't care about worn main journals because they didn't have crank savers. Cheap if they have crank savers.
 
Here's the 3/4" KT shaft. Looking reaaaaallly closely, looks like it has a nice thin sleeve to bring it to 3/
1585430407897.png
4"...
 
NOTE: sleeving can't be seen due to washer in the way on the crank end... but it appears to be professionally done. Got this from Charlie Stoffa, so wouldn't be surprised if he did it himself...
 
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