Hi, need help with briggs stratton

[rannedradda]

Hi everyone!
Im new here, but i´ve been hanging around the forum for some time, but this is my first post

Im building a mini chopper, and for engine im going to use a briggs stratton 1977 aluminum block 5hp horizontal shaft engine.

Im planning on buying a centrifugal clutch, but it requires an engine with a 3/4" crankshaft.

Im not sure if my engine has a 3/4" shaft.
But i´ve read in many threads on this forum that most briggs has got it.
Any of you guys know what size the crankshaft is??

And annother thing im a bit confused about is the size of the chain im going to use.
The clutch is fitted with a 41" sprocket, wich requires a 41" chain aswell. But where i come from(Sweden) i cant find any place to buy one.
But i found a page on the net with a diagram showing the different measurements on different chains.
It says that the only thing that differs a #420 chain from a #41 chain is the thickness of the rollerpins. The diameter of the rollers are the same. So wouldnt it be possible to use a #420 chain instead of a #41 chain?? Cause here in sweden i found many dealers selling 420 chains, but none of them selling #41 chains

 

[Kenny_McCormic]

Measure the crank
#40 will run on a #41 sprocket, not sure if I would do it with 420.

 

[rannedradda]

Ok thanks for the answer!
I´ve measured the crank, and it was almost exactly 19mm.
I calculated that 3/4" is about 18.8mm, so the shaft is a liiiittle bit to thick, but i suppose it´s caused by all the rust on it?

Anyways, ive ordered the clutch now, and i should have it here within a copuple of days.

Here is the link to the webpage i was talking abou. To me it looks like the #41 and the #420 chain has the same measurements, except the thickness of the pins as i have already said:rolleyes3:

http://www.gokartsrus.com/roller-chain-size-420-10ft-wmasterlink-p-8379.html?osCsid=2ccfa40f9f

Hope it´s a link, not sure, otherwise just copy paste it.

 

[r_chez_08]

3/4" is 19.05mm.