I'm working on a longtail build right now with a built 6.5hp (actually for racing karts) that makes about 12hp now. I have a good amount of experience in fab work and have designed a transom frame, but am a little bit stuck on how to make the driveshaft housing. I'm not sure if I want to go with bearings in the drive shaft or bushings. I feel like bushings would be more reliable, but thought I would get some opinions.

Also, I'm going with the standard 3/4" SS driveshaft, but debating on the size housing I want to go with. What is the standard for this? 1.25"?

Lastly, what have you guys been doing for seals? Do you just go with one seal on each end of the housing or are you doing something else? Thanks for the help. This is the only part holding me up right now. The last thing I want to do is fab everything up and not get it right. I figure if I decide on what diameter I want to do for the housing, I can go ahead and weld it all up and if I decide to do bearings instead of bushings, I can swap them out.

Oh, and where are you guys getting your lubricators from?

Thanks,

Mark

use the search function for each of your questions and you will find plenty of information,this is a great site to learn about doing a home build MM.if you cant find what your looking for post that question,there are some very smart and very helpfull people here.good-luck!

The big thing with that kart motor is knowing at what rpm's its making the most horsepower. Your really going to have to wind it up to spin the prop if you use one that is larger than stock, you will be able to spin the stock one faster though.

seals and lubricator come from mcmaster carr. usually 3 seals at the bottom 1st one put in backward to hold grease back, others put in to keep water out. and 2 seals at the top. Most use bushings, bearings take a lot more thinking about to figure out how to make them work