5hp briggs clutch mounting issue and bolt size??

J

JTalmage

New Member
#1
#1
I'm seriously >>.<< close to finishing my mini bike build.... but I'm hitting a fairly large snag..

So my engine is a 5hp briggs flathead and I'm using the typical centrifugal clutch but I have to flip the clutch so the sprocket is on the inside towards the engine.... so the chain lines up..

Only problem is, the keyway and set screws for the clutch are now useless. So what's a guy to do???

I bought a 5/16-24 bolt because that's what I saw all over the internet but it was a lie. I'm thinking it's a 3/8-24 bolt.

But is the bolt alone strong enough to hold this clutch on and keep it from spinning/slipping under load???

Thanks

Jesse
 
J

JTalmage

New Member
#3
#3
My crank is not that long. The clutch slides on, and hits the side of the engine, and the section of the clutch with the keyway and slot is not on the crank. If I flip it back around it would work but the chain would not be straight at all.
 
creia

creia

#4
#4
JTalmage said:
My crank is not that long. The clutch slides on, and hits the side of the engine, and the section of the clutch with the keyway and slot is not on the crank. If I flip it back around it would work but the chain would not be straight at all.
Click to expand...
What is the length of the crank?
Michael
 
T

the beekeeper

Active Member
#6
#6
You are going to need a longer crankshaft for your application, I have a short crank 5HP Briggs on my manco 2 seater kart with the clutch sprocket side out, it would not work in most mini bike applications without a jackshaft set up to align sprockets.............Tom.

I have a bunch of 5HP Briggs parts around here, if you ever get up this way I'll give you the crank you need.
 
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creia

creia

#9
#9
You are screwed with that short crank length. Start looking for a replacement crank with a business end at least 2.25" long. or another engine with one. Unless you are "married" or otherwise emotionally attached to your engine the latter may be easier and cheaper.
Michael
 
J

JTalmage

New Member
#10
#10
Well, I did buy a carb and intake specifically for it, and it runs well. I'll have to hit up Beekeeper to see if he'll ship that crank. I'd totally swap cranks at this point.

Someone else told me a Bravex style clutch would work, but I'd have to bolt it still, and I suspect the keyway still would not go where it needed to, and I'd just be spending more useless money. I already bought a new Max Torque clutch too... so at this point I'll put a crank in it.
 
T

the beekeeper

Active Member
#14
#14
It's out of an older non roller bearing engine, I could send the side cover with it if it will work, he said he had a newer Briggs, I'm not sure what changes took place in crank design over the years other than roller bearing in the side cover.................Tom.
 
Harquebus

Harquebus

Well-Known Member
#15
#15
A buddy of mine recently dealt with this shorter crankshaft issue on the Briggs 5 horse. He was offered a crank with an add-on section of equal diameter shafting...

Help with Crank for 5hp Briggs - DIY Go Kart Forum

I know, it looks and seems "janky" and ghetto-rigged but it looks like a go.

I recently sold a Baja Warrior I acquired with a Briggs 5 HP on it. I was shocked to learn the crankshaft was also stubby like yours, and the clutch was also reversed with the sprocket portion inward. The clutch bolt just barely made "purchase" with the crank threads. It was not something I wanted to rectify before selling either.

EDIT: a small portion of the key in the clutch made contact with the keyway on the crankshaft too, so the thing did work and operate but it was not ideal. That crankshaft extension idea at the link would be the perfect solution for everything.

Just a heads-up and FWIW.
 
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