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Discussion Starter #1
Alright guys, I need a little help to get things just the way I want them and I know there are people with the answers here. Here’s what I’ve got

Engine: 650 with the 732 big bore kit and Decker pipes (9400 rpm target)
Primary: 10-MR (44g) & Polaris blue
Secondary: Polaris T-1 (42/36/34) & Polaris silver/blue in the second hole
Gears: 21/39 with stock 9 tooth drivers in a wedge chassis

The engine revs out to 9200 rpm but after marking both clutches with a sharpie and going for a run at WOT, I found 3/8” to ½” of the mark remaining at the top of the primary and in the bottom of the secondary. So I have to assume that I’m not getting full shift out. Now, I know that I can get 9400 rpm by lowering the tension on the secondary spring but I don’t think that is going to get things shifting out fully.

I would assume this motor would be enough to pull 100mph on the speedometer but appear to be topping out around 85 to 90 as it sits. Right now, it pulls hard and strong at every speed and at every condition up to 85/90.

Anyone have a suggestion as to how to get this thing dialed ALL the way in? I know EPI recommends my setup but with 21/35 or 22/35 gearing. Can I be that far off just due to the gears?

Thanks in advance.
 

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Originally posted by saberspace
[br]if the motor makes enuff power it should run 108MPH with 21/39gear at 9400RPM. To get 200 more RPM tighten the secondary 1 hole
^^^ lol I believe it makes enough power.

I started a thread last week about gearing effects on clutching and still don't know any more than I did then lol. Yes I think drastic gear changes makes a big diffence in clutching. After redoing my gears I'm having the same problem. Haven't marked to see if belt is riding the whole clutch though. Mine seems to fall flat on it's face at 75-80mph, and I know there's more left.
 

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Some secondary helix's don't allow the secondary to open all the way. To check this, take out the primary spring and with the sled on a stand run the motor with the belt on. Your clutches will shift all the way out at about 1/4 to 1/2 throttle. You will be able to visually see if the belt is allowed to come all the way to the top of the primary. I the belt cannot come to the top of the primary you need to remove washer(s) from under the retaining ring on your secondary. If it goes too high you could add washer (shim). One .030 washer will move belt app. 1/6" in primary.
 

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Discussion Starter #5
If anyone's curious... I think I got it.

It was definitely not shifting all the way out but it wasn't the helix. I ended up going from 10MR weights to 10MB. Had to back off the secondary spring one hole and it appears to be just about right on although that gearing may be a little low for on the lakes.
 

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So how does the 732 bb kit work??? I've been waiting to find out lol.
 
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