Motor has 7/8" shaft, Kart parts are 3/4"...

[Dan from MA]

Hi all -

I'm planning on building a go-kart from plans & a kit. The kit is set up to use a Predator engine with a 3/4" shaft. I would like to use an electric motor instead, and the one I am looking at has a 7/8" shaft.

It looks like most of the kart sprockets available are 5/8" or 3/4"...is there an elegant way to connect the engine shaft through a jackshaft attached to a 3/4" sprocket? or do I need to keep looking and find a sprocket with a 7/8" bore?

Thanks in advance!

 

[Poboy kartman]

A 7/8" sprocket shouldn't be hard to find. You could always get a 1" and a bushing.

 

[ezcome-ezgo]

What's the pitch of the chain you are using?

 

[Wheelchock]

I had the same issue. I went to an industrial bearing and belt supplier and purchased sprockets and chain. You can probably find that on line too.
The grade/size is heavier and did not match any of the go-kart chain size (which seems to be more in line with bicycle parts).

So I have a heavier sprocket and chain set up on the motor side than I do on the other side of the jack shaft driving the wheels.

Some advantages - you can play with the ratio to suit your needs. I'm stuck with the 10:1 ratio on the drive side, but changed the motor side with a few different combinations.

One thing that I encountered - the heavier gauge chain and sprockets make some noise if the outside diameter is too small - see photo. I think I ended up with something like a 1:1 ratio on the motor side, but I used 18 tooth sprockets.