jack shaft housing for yerf dog 3203

[mdj89]

http://m.ebay.com/itm/391119841762?_mwBanner=1

Do you guys think this will fit an bolt on the back frame on my yerf dog 3203 for my jack shaft? Click on the top link for pictures

 

[OzFab]

Those are pillow block bearings & are widely used for that purpose, providing you have the available space & framework to mount them; whether or not this can be done on your kart, most of us can't tell without pics & measurements...

After looking at your previous threads, why do you need pillow blocks? What's the issue with the stock J/S housing?

 

[mdj89]

Well my 3203 kart has a subaru robin engine with 9 hp and I think its to much torque for the bearings in the original jack shaft housing because I went through I dont know how many bearings an they burn out so many times an I keep them greased up an everything. So I thought the ones on that link will hold up alot better.

 

[OzFab]

As explained in this thread, torque won't kill bearings, there must be another issue causing the issue:
- too much side load
- too much lateral load (chain too tight)
- inferior quality bearings
- bent shaft
...& the list goes on...

My opinion is "you can't see the forest for the trees"; the bearings dont last so, you instantly think the bearings are the issue, that's almost never the case...

 

[KartFab]

I use a 13 hp engine on my karts with the same bearings and they never have an issue.

Bearings are extremely susceptible to side loads like fabroman pointed out so lets just assume you are over-tightening them.

Stop over tightening the nut on the jackshaft. The nut should be finger tight, and even that may over do it.

1) put new high speed sealed bearings on the jackshaft (these ones require the snap ring style)

2) apply blue locktite to the threads of the jackshaft where the nut will go

3) tighten the nut on the jackshaft until it contacts the bearing, back the nut off.

4) use your FINGERS to tighten the nut until it just BARELY touches the bearing.

5) try and move the jackshaft in and out of the motor mount. It is tight enough when the jackshaft does not slide in and out. The nut is there to keep the jackshaft from sliding out, not to keep pressure on the bearings.

6) you should also have a spacer that fits in between the bearings on your jackshaft. This should hypothetically help more with side loads on the bearings from being over tightened.

PS your engine (9hp) is too big for the torque converter too by the way. The torque converter is only rated up to 8 hp. Thats your other problem. Best case scenario, you will always be wearing out the 30 series torque converter belts.

 

[Mr.Pedroza]

If you have the stock yerfdog 3203 check out bmi karts for the jackshaft housing with bearings and a new shaft ... Here is the link https://www.bmikarts.com/mobile/Clutch-Mount-with-Jackshaft-_p_1129.html

 

[mdj89]

No, im using a bigger torque converter for the robin engine its the 40 series an the bearing for the jack shaft housing does not have a nut to tighten. It just slides onto the housing. And its only the driver side that burns out.

 

[KartFab]

thats weird, and not what I have experienced when using a big motor on a small kart.

Those bearings you have linked are 1" bearings. If you do use different bearings, you will need the ID of the bearing to match the OD of the jackshaft.

 

[Poboy kartman]

No, im using a bigger torque converter for the robin engine its the 40 series an the bearing for the jack shaft housing does not have a nut to tighten. It just slides onto the housing. And its only the driver side that burns out.

That doesn't negate quite a bit of the possible problems Fabroman stated.....a bent shaft, an alignment issue.....or even side load....

 

[OzFab]

And its only the driver side that burns out.

In that case, my first guess is the chain is too tight

 

[Poboy kartman]

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