I have an old lawn mover engine with a 7/8 output shaft but since I couldn't find any 7/8" clutches, I bought a 1" clutch and an adapter sleeve to fit. The problem is that the key on the clutch is too big to fit on the smaller shaft. Are there any good solutions for this or are there clutches without a key so I can make my own key for it?
1" centrifugal clutch on 7/8" shaft
- Thread starter FhilipM
- Start date
ezcome-ezgo
G'me sumthin to write on
McMaster-Carr
McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
JimD
Well-known member
Call Max-Torque and get a 7/8 clutch to start with. Crankshaft has to be drilled and tapped and measure the length of the crankshaft so you can give that info.
Master Hack
Well-known member
Is this a vertical shaft engine? 7/8 is common for those.
ezcome-ezgo
G'me sumthin to write on
A suitably sized key from McMaster-Carr will be a few bucks.
JimD
Well-known member
McMaster-Carr normally has just about everything you need but they don't have the step key from 3/16 to 1/4". You would have to make your own from some 1/4" key stock.
Master Hack
Well-known member
I believe he's talking about the key that has been lanced into the bore of the clutch???
JimD
Well-known member
If he got a 1" clutch more than likely it would have a keyway not the built-in-internal key. Cost too much for a broach to do the internal key for such a limited market. Once you get to 1" crankshaft 99% of the time it would be a torque converter not a single clutch system. I would try and sell the clutch he has or see if he can return it. Get the 7/8" bore clutch because he will be doing a lot of work to try and get that 1" one to work but what do I know, he may enjoy the challenge.
Master Hack
Well-known member
Interesting, Mine has it. It's 1 inch. Maybe its a high end chinese knockoff?
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Yes! But I opened it to plug some oil channels and made a new oil flicker to run horizontally.
The problem is that the clutch I got does have a built-in internal key. Is it easier to bore out a bigger key slot on the crankshaft so the clutches key does fit?
(I will call Max-Torque to see what that would cost)
JimD
Well-known member
I stand corrected he does have an internal key, Philip is in Sweden and has converted the engine over to run horizontal which is a feat in itself. What a project. I guess this is his contribution to going green for the planet, don't throw anything away just use your brain to figure out how to make it work. When I kick the bucket my daughter will need someone clever like that to keep this place going.
Rat
Well-known member
It's really not, especially on most V-twins since they generally have a pressurized oil system anyway and it's mostly a matter of relocating and securing the sump intake head.
For smaller engines like say the Flathead on your typical push mower... yes it's more involved but it's still something one can do and have back running in as little as an hour or two. What is a bigger PITA on those is mounting them to anything easily as a Horizontal shaft since you need to use the old mover deck as a motor mount or at least as a template to make motor mount tabs on whatever you're doing.
At least with the big Vtwins it's 4 bolts holding the engine down, and 4 more holding the heavy deck plate. Thats an easy graft, No weird shapes or oddball bolt patterns
Waste Not, Want Not. I am forever using a broken this to make that, or cutting up one thing to make a bracket or what ever for another.
My 208 has the Canadian oil cooler and check valve pancake block off a big Kohler twin. I initially cut out the sump feed port and used it as the remote oil filter mount but the filter stub threads were pretty rough and I ended up getting an actual remote block... which was for a diesel and had to see some modifications to work.
$28 and modify
Or
$180 direct fit
Modify wins every time
Let me get an ETA on that, I'll dig yer hole pop
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qtband
Active member
Make the keys at on the shaft bigger by grinding. Done.