Sooo...I picked up a 1979 SRX 440 and it has a Comet 108EXP clutch on it as well as a 1 3/8th's width belt that's too wide for the secondary. From all the research I've done it seems the 108 is an overdrive clutch and therefore requires an overdrive secondary, unfortunately all my attempts to track down a new Comet 102c without the oilpump gear have lead to a dead end [Comet only lists the 108EXP for the SRX] Anyone have any tips on what to do to make the 108EXP work on a 1979 SRX 440? Or the correct part number for a 102c? Any help would be greatly appreciated!
Comet EXP108 work on a 1979 SRX??
- Thread starter Equalizer
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Think I just found the answer to my second question, looks like I need Comet 102c part # 212600 and a set of N-1 cam arm weights and a purple spring! Still hoping to make the 108EXP work but if all else fails at least I know what clutch to order....
opsled
Active member
You can shim the secondary open to work with the 1-3/8" belt by installing a 1/8" shim between the movable and stationary sheave. You must then remove the same amount of material from the snap ring side of the helix to allow it to open far enough so the belt can bottom out. If you don't modify the helix the belt will become tight in the secondary before bottom and the primary will not be able to fully close. This will rob all the power from the engine at full shift as it's trying to stretch the belt and shift.
opsled
opsled
That is a HUGE help, very much appreciated, thank you! I haven't done anything to the clutching yet but that seems to be exactly what it's doing now, pulls good and strong from a stop but then falls on it's face at about 80kph and the rpm's drop way down. The Comet primary has the purple spring but having trouble seeing what cam arms are in there, looks like C-1, will check it out better tomorrow. Thinking best to leave the primary alone for now till I do the modifications to the secondary and tune from there...
opsled
Active member
You can make that setup work very well once you get it right and the secondary is allowing full shift but it's still a mismatch of overdrive primary and non overdrive secondary.
I have no recommendations for tuning for you as I've never run it but do know there are many who do or have.
We run newer matching Yamaha clutches now. This is a setup off a 95 Vmax-600 that would also fit on your SRX. Overdrive primary/secondary with 1-3/8" belt that is tough as nails and endless tuning options.
Good Luck, opsled
I have no recommendations for tuning for you as I've never run it but do know there are many who do or have.
We run newer matching Yamaha clutches now. This is a setup off a 95 Vmax-600 that would also fit on your SRX. Overdrive primary/secondary with 1-3/8" belt that is tough as nails and endless tuning options.
Good Luck, opsled
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Damn, that is one nice looking snowmobile, the gold accents are a really nice touch!
We machined 3.17mm [1/8th inch] off the snap ring side of the helix and made a 3.17mm shim, set the off-set and distance on the clutches and went for a quick spin. Still doing doing pretty much the same thing, only now it's bogging off the line. Should have time this weekend to do some more testing and check into what cam arms are in the EXP108. Previous owner seems to have been a bit of a hack lol, so will have to go right through everything. That V-max clutch setup is certainly starting to look better and better...
Les
We machined 3.17mm [1/8th inch] off the snap ring side of the helix and made a 3.17mm shim, set the off-set and distance on the clutches and went for a quick spin. Still doing doing pretty much the same thing, only now it's bogging off the line. Should have time this weekend to do some more testing and check into what cam arms are in the EXP108. Previous owner seems to have been a bit of a hack lol, so will have to go right through everything. That V-max clutch setup is certainly starting to look better and better...
Les
