Tech Notes--F7 Snowmobiles

2005-06 F7 Tech Notes

Clutch Kits
Ran stock—sled has 200+ miles on. 108 mph in BW ditch at 8020 rpm on packed snow. Raced LC’s F7—dead even.

HeartThrob Clutch Kit Part # 80-2794--for a stock sled (3/8” of spring tension)
*Would run 4-6 lengths faster than LC’s stock F7 in the BW ditch. Pulls pretty darn hard—Larry likes it. End test.

Black Magic Clutch Kit Part # 80-2799--This clutch kit is to be used with the Black Magic Super single pipe
*Raced Larry’s F1000 in the BW ditch. 1-2 lengths ahead out of hole to ½ track and would be 1-2 lengths behind after a ½ mile and would stay there. Pretty fast for 16 hp Less! Runs 7800- 8000 rpm. Pulls pretty good!!!

3/8” spring tension to start, adjust as needed.

2004 F7 Tech Notes

Clutch Kits
This year, the sleds came with a Kevlar based belt. The weights needed to be increased due to the hardness of these belts. The F7 had a 0627-031 belt. We had to go to a 72 gram BM weight.

HeartThrob Clutch Kit Part # 80-2768--for a stock sled
*This was done on a carbed F7. Stock jet was a 510N. Way too rich. We went to a 470 main, and still could go more. Raced LC’s F7 and beat it by 4-6 lengths in the BW ditch. Runs 7800 – 8000 rpm. Good to go.

Black Magic Clutch Kit Part # 80-2755--This clutch kit is to be used with the Black Magic Super single pipe
*Due to the Kevlar belt(031), we had to weight it up—we used a BM 74 gram and cut one gram off the bottom—a full length cut. It will run 7800-8000 rpm at full shift out. Raced AC’s 900’s and got them by 8-10 lengths in a ½ mile!!!!!

Run a 460-470 main jet on the carb models at 0-20 deg. F. EFI’s—no adjustments needed.

2003 F7 Tech Notes

Clutch Kits
Tested on Pine Lake. Stock was 108.3 mph in a ½ mile on an ice groove.

HeartThrob Clutch Kit Part # 80-2646--for a stock sled
*112.86 mph in the same distance with the HeartThrob Clutch Kit. .2-.3 tenths quicker in 1000’. Completely woke the sled up. Stock sled was clutched too light.

Use stock gearing and the stock 10-tooth driver.

Black Magic Clutch Kit Part # 80-2674--This clutch kit is to be used with the Black Magic Super single pipe
*Comes in at 7800 rpm and will build to 8000. This thing goes like a scalded chicken—114-115 mph and climbing in the ditch out front here. It is a good idea to put on the engine retainer kit. The motor mounts are too soft and the motor moves all over.