Belt requirement not matching belt chart

[qpgmr]

I'm swapping motors on a Yerf Dog 3203 from 195cc Tecumseh to 224cc Predator but I had to abandon the clutchplate and switch to a clutch mount bracket because the larger motor doesn't give the clutchplate room to be there. The clutch mount sets the shaft spacing in stone, but is basically the same spacing as before with the plate. I have a 30-series TC with 6" driven pulley and 6-5/8" center-to-center. According to the belt chart, I am prescribed a 203589.

This is too tight. When I pinch the belt near the drive I can't really get any separation from the bushing, and there is no curvature between the spans in the belt at rest.

I was thinking about buying the 217248A but wanted to ask, any ideas why this chart doesn't work for me? I've already had one of these belts bind on me with the previous setup with the clutchplate, which again was the same center-on-center spacing.

 

[Denny]

That’s just the way it works out sometimes. Just step up to the next size. Remember USE ONLY GENUINE COMET BELTS!!!

 

[qpgmr]

I did indeed buy genuine Comet. I'm still unsettled as to why though. These are very specific numbers and my C2C is at the small end of the range for that belt so it should fit easily to the point of being loose, theoretically. I was assuming the problem was mine and also assuming I would have seen many others saying the same if it wasn't my issue.

 

[Hellion]

Could the driver and/or driven be out of spec or worn, making the belt too tight? Because they are variable sheaves they might possibly be adding some tightness, that’s the only thing I can think of.

Is it a genuine Comet TC?

 

[Master Hack]

I ran into a similar problem, inbetween the sizes on the chart. The next larger size works well. Your description of the belt with no deflection, means the next size will be good.
I was surprized how loose the correct belt is.
the reason ya use comet belts is cuz the last.
l have run the same comet belt for 50 hours so far. I cant find a reason to change it.
The chinese yak fiber belt failed in about 4 hours.

 

[qpgmr]

Could the driver and/or driven be out of spec or worn, making the belt too tight? Because they are variable sheaves they might possibly be adding some tightness, that’s the only thing I can think of.

Is it a genuine Comet TC?

Yeah it's gotta be the driven. I'm sure I overtightened the nut, the top of the belt isn't flush with the top of the flanges. Thank you for the insight.

I see it's 20-lbs for the driver, how tight should I make the driven?

 

[Hellion]

I see it's 20-lbs for the driver, how tight should I make the driven?

No idea, but 20 sounds good. I hope it’s 20 foot-pounds and not inch-pounds. The forum gray-hairs may know it off the top of their heads but here’s some manuals, knock yourself out:

Comet Torque Converter Manuals & Documentation

 

[qpgmr]

Just wanted to share an update so maybe others won't struggle with this as much as I have. The retaining nut had nothing to do with it. It seems that my spring was too tight. I had been watching a video that in retrospect seems misleading on how to preload the spring and caused way too much resistance, preventing me from being able to pull the driven apart to seat the belt. The correct belt looks like a perfect fit now.

That said, now I'm reversing course, sending the clutch mount back and getting a riser for several reasons, including assurance of pulley alignment and being able to have a belt cover(I belatedly realized the need for keeping as much dirt away from the TC as possible). The new issue that pops up in doing this is the exhaust pointing right at the frame rear, does anyone have any ideas at diverting the exhaust back down?

 

[qpgmr]

This should work.

 

[Hellion]

The new issue that pops up in doing this is the exhaust pointing right at the frame rear, does anyone have any ideas at diverting the exhaust back down?

Seems like you have things in hand. I think people routinely discard the factory muffler in favor of a pipe so I was surprised to see a link to the exhaust deflector. That is a common upgrade though and works well.

If the deflector is unsuitable with the limited range of angles it gives you, there are all kinds of headers or long exhaust pipes that could be used. The best come threaded for a screw-on muffler/spark arrestor which tones down the pipe quite a bit.

Have you got pics of your Yerf-Dog you could share to illustrate your work?

 

[qpgmr]

If trying to get the most out of it I would have gone that route, but this is for girls that don't appreciate the noise. I don't either, to be honest. I'd like to preserve what hearing I have left. 2 of them are still smallish and don't want their wondering hands brushing a hot pipe sticking out. Also, this is mainly for a track I cut in the woods so I don't want it to have a lot of top speed anyway. The Tecumseh I just took off it had a pipe when I bought it and that's it, and I had to put a muffler on it because it was way loud. Yikes.

I'll take some pics, not sure it's worth doing so yet since it's not together. It's also pink.

 

[Whitetrashrocker]

Nothing wrong with pink.

 

[Edwin Spangler]

If trying to get the most out of it I would have gone that route, but this is for girls that don't appreciate the noise. I don't either, to be honest. I'd like to preserve what hearing I have left. 2 of them are still smallish and don't want their wondering hands brushing a hot pipe sticking out. Also, this is mainly for a track I cut in the woods so I don't want it to have a lot of top speed anyway. The Tecumseh I just took off it had a pipe when I bought it and that's it, and I had to put a muffler on it because it was way loud. Yikes.

I'll take some pics, not sure it's worth doing so yet since it's not together. It's also pink.

Any pictures youre willing to post are worth it... We like progress pics as much as completion pics.

Also, about the spring being too tight. I keep the preload on my driven as tight as possible. Ive even drilled more holes to make it tighter. It requires two people to assemble it. You shouldnt have to separate sheaves to install the belt.

 

[qpgmr]

You shouldnt have to separate sheaves to install the belt.

So the spring forces the sheaves closed. The question then becomes, what is allowing the spring to force the sheaves to close too much?

 

[Edwin Spangler]

So the spring forces the sheaves closed. The question then becomes, what is allowing the spring to force the sheaves to close too much?

At rest, it should be as closed as it can be. On the 30 series, I just force the belt around, kinda twist as I go BUT the proper way to do it is disassemble the driver and remove the front half. Then you put the belt on and reassemble the driver.

Forcing the belt around the pulleys like I do, that shouldnt be easy.

If the sheaves are closing, making the bevels too narrow for the belt at rest, I would think the belt is too wide. I may be misunderstanding though.

 

[qpgmr]

I'm using a 203589, which is for 30-series. My pulleys are asymmetrical, so that indicates 30-series, I believe. The sheaves are not open by the 3/4" width of the belt top.

In any video I've seen, the top of the belt looks like it rests between the sheaves easily. My driver is already disassembled so that's not an issue.

Then there's this tidbit from AI, granted it can be wrong.

Edit: I rewatched a video and it was pushed into the driven, it was quick and I missed it. I have to disassemble it again anyway to replace a button, so I'll try it again with the 90 degree counter-clockwise twist on the spring and see how it goes.

 

[Edwin Spangler]

I'm using a 203589, which is for 30-series. My pulleys are asymmetrical, so that indicates 30-series, I believe. The sheaves are not open by the 3/4" width of the belt top.

In any video I've seen, the top of the belt looks like it rests between the sheaves easily. My driver is already disassembled so that's not an issue.

Then there's this tidbit from AI, granted it can be wrong.

Edit: I rewatched a video and it was pushed into the driven, it was quick and I missed it. I have to disassemble it again anyway to replace a button, so I'll try it again with the 90 degree counter-clockwise twist on the spring and see how it goes.

View attachment 162263

I meant bevel when I said bevels. Youre right, its asymmetrical.

Yes you need that twist to preload the spring.

AI part sounds about right. I was saying if the sheaves are so close that the belt cannot fit between them, that would be a problem.