Changing drive and axle sprocket size and modify lower body?

[soutthpaw]

I am wondering if anyone has changed the size of the main drive sprocket on the center axle that is about twice the diameter of the wheel sprockets. I just cleaned my tub out today and removed the rusted in chains. I noticed there the a recess made into the bottom of the body for the bigger drive sprockets. the body has be cut through on one side of mine by the large sprocket rubbing on it. That body recess also takes away from the ground clearance. I would like to go with a smaller sprocket and then heat and mold the tub smooth to match the rest of the bottom. I suppose it would also be possible to go with smaller sprockets on all 6 drive wheels in order to maintain a usable final drive gear ratio.
it will be the challange of balancing increased top speed against lower torque and power.... thus change to bigger engine maybe to make up for it...

[wfo]

contact whipper

[Robinhood02]

how many teeth on the large sproket ?? if it is 30-35 (or more) teeth then putting on a sproket with a couple less teeth wont change the top speed all that much, but if it is 19- 23 teeth then you may have to make other changes as well, a couple teeth smaller is all it should take to give the clearence you need

[soutthpaw]

the T-20 is 15 teeth, large drive sprocket is 41 and the wheel sprockets are 26 teeth.
thus 41/15= 2.73:1

[jerseybigfoot]

Changing the wheel sprockets will not gain you anything. Reducing the trans sprockets on the center axle to 34 teeth will make it the same gear ratio as a Max 4. A 18-20 hp 4 stroke should pull it fine. If you up the size of the converter on the t-20 you will gain your low end back. If you go with a larger converter on the trans you will need to raise the trans up so the converter clears the left rear chain. I plan to mod the tub on my 980 bigfoot tub to remove the bump also. Because of the large area that needs to shrink I would make a plywood mold to fit the inside of the bottom as to not warp the sides.

[soutthpaw]

Thanks Jersey, you kind of answered my next question about if you change the drive gear to smaller what would be the effect on the tranny. I was also reading the salsbury converter manual in the links section. By using a smaller drive gear I would be lowering the final drive ratio which would also have the tranny output shafts spinning at a much lower rpm for the same ground speed. This I am guessing would increase the torque required to run the tranny hence need for a larger engine or a torque converter that is slower to ramp up and demands more load to do so???

I have the K341 kohler at 16 hp but I saw some folks mention they can be beefed up to mid 20's HP wise. need to find out more about that. guess the lawn tractor racing guys do mods to these..
Good idea about the plywood too
Just waiting for my buddy to get back to me about making the axles and cost... That way I can just fire up the plasma cutter and cut all them rusted axles and sprokets out of the machine... I will post up once I get an idea of the prices for the axles, sprokets, bearings etc. If aprice is good he may be willing to do a run of them and make complete pkgs to sell.. also thinking of having a dual stud pattern, the standard 5 on 4 1/2 inches and then a 4 on 110mm as it seems to be a common atv bolt pattern so if going with diff rims would give more options...

[jerseybigfoot]

If you are considering axles and sprockets, Its an easy upgrade to 1 1/4" axles as the bearing flange is the same. If you really want to go all out you can modify some early 90's Argo bearing/ seal housings by adding another flange hole to it and bolt it to the 3 hole bearing flangette. The Argo seal housings give you some additional sealing for the axles.
Here is the link for modifying your Kohler. http://www.midwestsupercub.net/1%20cyl%20parts.pdf

[brushcutter]

I made an attempt at reshaping the lower tub on my 950, but couldn't get enough heat over the entire area. Doing this mod will require a large heat source, my thoughts are to use a pan with charcoal, which could be moved out of the way once the tub is hot enough to be reshaped, I built a mold to shape the tub bottom but I believe you will need one to match the inside as well. I also think you will have to do this with the top off and the frame out. My reasoning is that this mod will greatly increase the hustlers' centerline ground clearance, and should also help it to swim better. below is a link to my thread on this.

http://www.6x6world.com/forums/hustler-atvs/8660-annoying-bump-under-hustler-tub.html?highlight=annoying+bump+tub