Help with clutch adjustment and identification on Coot

[allwheeldrive]

As an update. I re-positioned my engine, it’s now moved over 5/8” Which isn’t much but I figured it be better than nothing and I knew how not moving it worked (not good). So I bought another new belt this time a direct replacement for the Coot’s original. With the Engine moved over 5/8” It makes the belt essentially 1.25” shorter than the original and about 1” longer than the short belt I bought. So I’m pretty much right in the middle of correct length and too short.

Now I have a heck of a time getting the RPM’s down enough to change gears. BUT it’s do-able. Could not with the short belt at all. The problem is I’m still slipping in 2nd and reverse just like before. When in first gear I haven’t noticed any slip where before it did (original belt / original engine position.) So that’s better… but still unacceptable.

I swear the worst thing about working on machines like these is there is no consistency. Which makes problem solving almost impossible.
For some non-apparent reason now my engine Ideals maybe 100RPM higher than before. I know this because before I needed to use two Popsicle sticks wedged behind the throttle lever to keep the engine happy and not stalling. It was nice because when in use I could just let off the gas without the Popsicle sticks and drop the rpm low enough for smooth gear changes. Now the machine maintains that RPM with no spacers and is likely contributing to the much harder gear changes.

But wait there’s more. My transmission seems to be MUCH harder to physically get into gear. And it pops out of 2nd while driving around like if I go over bumps. Which is never did before. I don’t understand how moving the engine has made the gear shifts harder and the RPM increase.

I had a theory. Which was the engine is moved back (not to the left) but back about ¼ of an inch. This was unintentional just a byproduct of trying to drill out new holes threw 3 layers of steel plate and not getting them all perfectly aligned. Perhaps the ¼” of back travel has changed the resting position of the idea throttle (due to the fact the cable is pulled ¼” further to increase ,my base RPM)

Now that also means my primary and 2ndary clutch are no longer in perfect alignment. With the engine clutch ¼” back from the driven clutch. Both clutches are perfectly parallel, just offset. I know that isn’t idea,l but I didn’t think it was a deal breaker. If I get 50% less belt life I’d be fine… seeing as that would still be many more hours than I have ever driven this thing.

The question is having the belt misaligned that little, could that somehow cause friction in the transmission and make it physically hard to throw the shiftier forwards and back as well as popping it out of gear? I’d think not, but what else has changed since I last drove it? Nothing.
I’m now wondering if I should try and pull out the driven clutch and really rough up the surface to get more bite. It’s driving me nuts that there are CVTs on Polaris SxS that can handle 140 HP and I can’t manage to get my CVT to transmit 9.

[ARGOJIM]

That is a Serp belt NOT a CVT belt .
You need a Belt for a Snowmobile .

It also looks like though you currently have a variable speed belt that the angle and depth of the belt may be small like some goodyear equipment belts.

[msafi65]

Dirtdober's post also has the weight and spring chart I've bee looking for. Thanks.

[dirtdobber]

Allwheel, look at the chart about 6 pages into this document. http://forums.bajasae.net/forum/uplo...TY_CATALOG.pdf

This gives you the required CD (center to center distance - crankshaft to transmission input shaft) and related belt part number, all based on the type of clutch configuration you have. To get the correct belt tension, you have to get pretty close to these dimensions, because there aren't a whole lot of options when it comes to belt lengths.

[wedge]

That is a Serp belt NOT a CVT belt .
You need a Belt for a Snowmobile .

[allwheeldrive]

OHHHH! that makes sense now

Though now I'm not sure if I should just put the clutch back together and try a bigger belt. It stinks I have no room for adjustable as it is, the coot's tub has been bent and cut to fit the engine from side to side. And it seems like 1/2" of belt makes a huge difference in tightness. 52" = a full FOOT of deflection, 49" = 1/2" of deflection. I might be able to get by with a 50-51" belt, you mentioned you can run belts from 1.156" to 1.218 wide. I'd think the wider would engage faster. Or maybe the difference is so minute it doesn't matter? The list of belts provided seems lack anything between 48-and 51 less than 1.4" wide so maybe this isn't an option after all.

Am I right to think a belt of this design will not work? With the grooves facing length wise? https://www.amazon.com/Gates-500L6-M.../dp/B00CJKB6X4

[dirtdobber]

That red spring you saw is in the driven clutch, not the drive clutch. You are working on the drive clutch.

[allwheeldrive]

If the movable face moves in at idle the clutch is wrong. If it truss to crawl when cranking the belt is to tight. I see several belts listed in the 42.5-44" Carlisle spec sheets. The max series belts are measures to the top width and do not taper to the edge. I run belts run them from widths listed as 1-5/32-1 7/32 top width. Also put a tacometer on engine and slowly raise speed until you see the movable face of the clutch jump in. Usually 1200-1700 rpm is in the ballpark. Then call Don Jackson 608-774-0481
He can tell you what weights and springs make up any engagement speed you want. He is at Certified Parts Corp. the company that now produces comet products. Hope this helps.http://www.hiperf.com/acatalog/beltdimensions.pdf
Check out Max3 dimensions, I see the top widths have gone away from 32 of inch from my old chart.

Thanks for the link and info, I'll look into it once I figure out how to take this thing fully apart.

[allwheeldrive]

Allwheel, look carefully around the center shaft and see if has any swollen spots as a result of someone driving it onto the engine with a hammer. A swollen spot will keep the outer cover from coming off. If you will take a file and dress the outer edge of that center shaft it may help you a bit, if it is in fact swollen in places.

THANK YOU! I wouldn't have thought that could have been a possible problem but it was what had to be done. We removed a scary amount of material before it finally slipped off. The weird thing is the metal was mushroomed out exactly as you described but from the inside edge not outside almost as if extreme force was pushing the bell housing up. Well the cover is off and now I have more questions. I see the 6 horizontal springs set in their 3 groups against the rollers they are very rusty I see no way to identify what color they once where. The thing I'm confused about is whether or not there is a "main vertical spring" Such as this: 300397C DRIVEN SPRING RED 780 DRIVEN - COMET

I don't see any big center spring like on the duster just the 6 small outer springs, is there no main spring as I linked above hidden somewhere? And if so how do I access / find it? Do I have to remove all 6 smaller springs first?

Thanks for all the help guys!

[wedge]

Good point ! I forgot about that

[dirtdobber]

Allwheel, look carefully around the center shaft and see if has any swollen spots as a result of someone driving it onto the engine with a hammer. A swollen spot will keep the outer cover from coming off. If you will take a file and dress the outer edge of that center shaft it may help you a bit, if it is in fact swollen in places.

[wedge]

Spray some PB Blaster on the center of the Bell where it is center shaft then Gently pry it around the lower edges to pop it off.
Looks like it is just rusted on there ?
The only thing holding the bell on is the snap ring and the 3 bolts so it should just pop off !

[allwheeldrive]

Why is this so complicated?



Ok my buddy and I are stumped after wrestling the clutch out and taking everything we could off of it (bolts, retaining c-clamp) all it does is rattle we can NOT find a way to open the unit. What are we missing? If we pull up on the outer curved case all it does is hit the flange of where the C-clamp was.

For such a popular unit it also bewilders me that we can not find any videos or "how to" in dissembling it.

[msafi65]

If the movable face moves in at idle the clutch is wrong. If it truss to crawl when cranking the belt is to tight. I see several belts listed in the 42.5-44" Carlisle spec sheets. The max series belts are measures to the top width and do not taper to the edge. I run belts run them from widths listed as 1-5/32-1 7/32 top width. Also put a tacometer on engine and slowly raise speed until you see the movable face of the clutch jump in. Usually 1200-1700 rpm is in the ballpark. Then call Don Jackson 608-774-0481
He can tell you what weights and springs make up any engagement speed you want. He is at Certified Parts Corp. the company that now produces comet products. Hope this helps.http://www.hiperf.com/acatalog/beltdimensions.pdf
Check out Max3 dimensions, I see the top widths have gone away from 32 of inch from my old chart.

[allwheeldrive]

Googling 780 series comet it does look like that model, it does squeal a lot, especially when I turn the engine over while in gear (as there is NO way to change out of neutral once the motor is running) In fact the starter will actually turn the tires the clutch engages so fast! There is sadly no way to adjust belt tension. The engine and transmission only have one place they can be bolted to the floor, the old belt was 52" and as I mentioned unbelievably lose. I made a mock up belt that fit perfectly at 42", the closest belt size I could fine that matched was 42.2" so it really was pretty much perfect. In the 1 3/16" belt thickness I'd have to drop to a 39" or go up to a 56" the is no other in betweens and I looked everywhere.

Wedge don't tell me that, it took 2 hours to get them nice and rough with some 320 grit sand paper! Lol, I really don't think the roughness is the problem, It could be contributing but I think the springs must just be set too soft. I'm really hoping it can be modded like my older Comet, anyone have pictures of one of these dissembled?

http://i130.photobucket.com/albums/p278/chriskent85/IMG_20150121_172714474_zpslgqcdtu8.jpg

Yikes this looks complicated how is one supposed to adjust this? Buy new springs? Where would I even start?

I now recall my old one was a Comet Duster. That thing was super simple, though I doubt it could even fit in the small space in the coot.

Thanks,