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.