503 bell housing removal

[techfx]

Any BRP/Rotax guys here that know how to get the orange bell housing off the 503 (maybe it's identical to other Rotax models). I finally found a puller but, It looks like I need to get the housing off before using it.

Thanks,

Mike S.D.

[Amphiman1]

rotax

hi! they have one way valves to put in the fuel line too about 4.00,: so fuel doesn't drain back....... might be a cure,,,,and inexpensive too

[mountaintoyparts]

Are you talking about the clutch? The dome shaped part of the clutch? The rest is black or aluminum?

[techfx]

Correct, on the older ski-doo clutchs it's orange, the rest is aluminum. The only size pullers that I've learned work w/ old ski-doo clutches is 5/8 thread. That is too large in diameter to fit past the orange housing. The only other options that I have seen in any other catalog are 14mm and 16mm. Those also seem a little large (and I think I've already tried to fit regular bolts those sizes into the threads)

[mountaintoyparts]

Yes, it will be metric, I have pulled them off of old Ski Doos many times. It looks to me like you don't have the room to get the cover off. I assume the bolt came off through a hole in the tub? Once the bolt is off the orange cover SHOULD pop off but you need a few inches of clearance to get it past the fly weights.

[techfx]

Fourtunately, since my machine is sitting and waiting for my 2 new rear axles to be installed, I have the engine tilted off the frame and have good access to get everything off. Does the cover just come straight off or do I twist/thread it off somehow - just don't want to damage it in case I may have to use it again.

I will have to cut hole and add a "pie pan" if I go to a comet clutch or something. Some of my uncle's racers had that modification.

[hydromike]

Hey Tech...

Hmmm.... I'm up in Irvine this week. I wish I could have come down to lend a hand...

The orange belhousing should pop right off (no twisting in my experience) after the clutch bolt is removed. Are you taking it off to inspect the rollers? If you've gone this far, it would be great to be able to upgrade to a different clutch. The SkiDoo clutch is great for the sled, but it's very, very difficult to adjust for the AATV. The puller is obviously the best way to get the entire clutch off, but if you're in a desperate (DESPERATE) pinch, I've used small propane torches on the clutch shaft where the belt runs, and a plastic mallet. Yeah, I'll get flamed for this suggestion, but if you MUST get it off, it works 95% of the time. Small, swift blows are the key.

Also, you don't necessarily have to cut a hole in the side of the tub to make room for the clutch. Save the bowl, and use it as a dolly. Heat the side of the tub up with a heat gun (or the same propane torch you used for the clutch) and get it goooooood and mushy. Polyethylene is great for this. Get it nice and hot (keep the heat moving around, don't stand in one spot too long) and then mush out the softened plastic with the bowl. Keep a bucket of cold water handy to "flash-freeze" the hot plastic in place once you obtain the desired shape. It works! Really!

Good luck.... let us know what you try, and what works...

~m

[techfx]

Mike, I was just up there to go to Medival Times last weekend... let me know before you're out here next time.

I'll try just yanking off the cover (not much to grab it with). My hope is (after knowing for sure the drive shaft size) is that I can "borrow" one of the old comet clutches off one of my uncle's racers or something else that matches the belt size that the t-20 wants. I just ordered a puller that should work (don't know the year of the sled it came from to be sure) The clutch was close before but, not "Attex speeds". I think my name was covered up by someone on Whipper's wall so, I got to get my stuff together and get some air ASAP.

[techfx]

Success!


Here, I borrowed my cousin's giant channel locks to squeeze the plates together and pryed the cover w/ a screw driver to get it off. (this is just a re-enactment after getting the clutch off)





This was my method of getting leverage while using the clutch puller (5/8" threading on the puller was correct - the metric sizes came in later years): breaker bar w/ 19mm socket and my cousin's giant channell locks again.





Finally - maybe I'll get a good measurement on of the drive shaft when I have access to a micrometer on Friday.





as soon as it broke loose - as usual drawing blood from somewhere.





A poor attempt at a measurement of the drive shaft

[hydromike]

Nice work!

I just realized that by using any other clutch, you might forfeit the use of the electric starter. Not sure if this is a big deal to you, but just a thought. Most every clutch that you try to use is going to be a 30mm 10:1 tapered shaft. It's been the industry standard for a long time. Shouldn't be hard at all to find one that'll be tuneable (like the Comet) to suit you.

~m

[techfx]

So , I've spent the past few hrs researching what clutch to get. At this point I'm looking at:

1. newer OEM (TRA) clutch - the shaft is the same size, looks like I may be able to use my starter ring gear and there appear to be some after market parts for this to change performance.

2. Comet 102c - looks very tuneable but, no go for the ring gear for electric start.

3. Comet 94c - is the least expensive, can be tuned a little from what I can tell and does have holes for rotax starter ring gear. The only downside is that it is noted only for up to 440cc. I'm at 496cc. Not sure if this would cause any issues or not.

I'll keep looking but, for now this is what I'm shooting for.


If anyone has any suggestions/clutches to sell that would fit, It would be much appreciated.

[techfx]

Okay, So, I've got it down to comet 94c clutch 209942A, it has an engagement of 3100 rpm and uses a 1 5/16" top width belt also will accept a starting ring (rotax). (Thanks to Don Jackson from Comet)


Does anyone know how this increase from 1 1/4 to 1 5/16 belt will effect the secondary clutch? That's the only thing keeping me from buying it at this point.

[hydromike]

I've run a 1 5/16 on my 102C for some time. I can't see that it negatively affects the secondary clutch in any way. It probably won't engage the secondary *quite* as much, meaning you'll lose a little on the top end...

... but I mean... hey man... it's a Rotax... 'ya gots plenty of top end to play with.

~m