Just wondering how much clutching can affect your gas consumption in a sled. I had a 98 SRX which I found to be great on fuel. I now have an 00 SRX which is hard on fuel. Both sleds were stock. The only major difference I can see between the sleds that might be killing my fuel mileage is the clutching. In my 98 I used Dalton DPY 55.5 weights in the primary, 53/45 Helix with a green yamaha secondary. The 00 has 8BU-00 in the primary with 51/43 helix and green yamaha secondary. I beleive the 8BU-00 are a heavier weight so could this increase gas consumption? It seems to me that it would take more "throttle" to force the heavier weights.
yes it will be worse on gaz if the engine is always on load
bluewho
Active member
If you have a clutch puller it would be interesting to swap both setups and find out.
progold
New member
My thoughts exactly.bluewho said:
Judging by the wieght, Your engagement is higher on the 00 right? The higher the engagement that's more fuel burned. Also do you do lots of trail riding? The 8BU-00 is a very poor back shifting weight. Most of it's mass is the the lower end side of things. There is a steeper engagement ramp.
Riding many miles side by side with an SRX I always figured the better gas milage in most conditions compared to my SX was due to the SRX not having to rev as high to run the same conditions?
bufalobob
Member
agressive clutching will reduce fuel mileage.
yamaha has always used wimpy secondary springs in order to let the belt shift out quicker, thusly reducing cruising rpm's allowing better overall fuel mileage. this situatuation, however, is not conducive to crisp overall performance by allowing the clutches to actually overshift under heavy load conditions ( sucking the belt into the secondary ) and causing those deep groves in the primary sheaves just above the shaft & all the fissure cracks that then appear in the sheaves. they finally got it right w/ the 4 strokes.
bob
yamaha has always used wimpy secondary springs in order to let the belt shift out quicker, thusly reducing cruising rpm's allowing better overall fuel mileage. this situatuation, however, is not conducive to crisp overall performance by allowing the clutches to actually overshift under heavy load conditions ( sucking the belt into the secondary ) and causing those deep groves in the primary sheaves just above the shaft & all the fissure cracks that then appear in the sheaves. they finally got it right w/ the 4 strokes.
bob
progold said:
Thanks for all the replys guys. I sold my 98 but I am going to to try a different clutch weight (probably the Dalton DPY-57.5) and see how this works. Someone mentioed about the 8BU-00 not having great backshift and that is one thing I did notice. Once we get some snow I'll post my results.
tedgoesfast
New member
a properly cluthed sled will see a big improvment in gas milege myn sx 700 in stock form got about 11 mpg canandian.when i clutched it properly iam getting around 17 mpg in good conditions
bufalobob said:
Thanks for the info. Makes sense. I do have one question. You mentioned that the light clutching on stock SRX's allowed the belt to drop in the secondary under heavy load conditions. Wouldn't this mean it would raise in the primary. If that is the case how does this cause the groves in the prmary just above the shaft. I have noticed these groves on my clutch and just figured it was from excessive idling or something.
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