My jackshaft setup version 2.0

[Grimace]

This didn't work. Not because of the red spring in the driven pulley, but because I didn't think it through. The bracket flexes under a good load, and it shucks the chain.

This is what I came up with from bmikarts.com. I just hope I have enough room for the mount without modifying the upper roll cage mounts.
Thoughts?

 

[r_chez_08]

Cool design, it would have probably worked great with a 5hp or something. Not beefy enough for your motor though.

Since you already have the bearings and j/s why not have a shot at making a setup similar to the BMI one that can be tailored to your needs?

 

[Grimace]

Well, surprisingly enough, I am going to use the current jackshaft and bearings for my sons kart. The bearings seem weak anyway, and like you said, probably are better suited to the spare engine I have instead of the 420cc powerplant. This new bearing set looks to have a much better sealed bearing assembly. Plus, the red jackshaft plate hung off of four 1/4 inch bolts on the engine block. It is really heavy. And I think I under-engineered it for the big engine, but way over-engineered it for a child's kart. Did any of that make sense? It sounded so good in my head.

 

[Grimace]

Oh, btw R Chez, what is that silver box hanging off of the exhaust manifold? Looks like it has holes in the bottom of it.

 

[mckutzy]

I forgot to ask the same about that a wile ago. what is this "thing"?

 

[Grimace]

Ok McKutzy, I found out what it is. It is an emissions thing called a flame arrestor. It is to contain lean exhaust "backfires" and such to keep from burning the world up.

 

[r_chez_08]

Yeah I think it is something like that. Not seen one before.

 

[mckutzy]

I thought they were an internal thing, or just a screen at the end of the muffler opening.

 

[Grimace]

My source for the info told me if it is removed and blocked off, it will make the exhaust louder. Not sure how, but cool. I need to build my own exhaust for my clone engine. Something loud, and obnoxious. Like a straight stack with a magnaflow race bullet muffler. That way it will still have backpressure, but be really loud. Plus I can add a tractor flapper for the muffler tip. That stuff shouldn't need any carb adjustments.