clutch results...

[Viktory2k1]

Hi
Went on the lake today to test new purple drive clutch spring and all good so far.
It now engages at 4500 rpm but tach may not be accurate but higher then old spring. Old one was around 4000 rpm.
Lake alittle weird now due to thawing and refreezing so took it easy.
Everything I will refer to is what the gauges say. This sled has 48 studs on a cleated track also. Now track will spin on bare ice and try to pull skis up but I sat towards the back to prevent that. I have 24 new studs and going to order another 24 and put them in during warmer months.
If I go 20MPH and floor it, tach goes to 6500 and steadly goes up and speedo goes up much faster. Way faster then before with unknown spring. I have a 80mph speedo and I glanced at it and it was almost in 3 o-clock position and rpm was 7000. I stopped and looked and I was at 7000rpm and 60mph and still pulling strong. I dont like to look at the gauges while riding that fast just see where needles are and check it when stopped. I dont know if tach is broken(maybe)but never went above 7000rpm. I will mix fuel 40:1 from now on just in case.
I do not want to over rev engine but with the handling issues, I dont think I will go any faster, for now.
I would recommend a purple comet spring for all cyclones as of now.
Just get more studs.
Vic

[jd_decalguy]

Vic, I don't have my fine tuning manual with me & I'm not sure if your talking about the Cyclone or which sled your on?
But IF it is the Cyclone I'm thinking that 7000-7500 is about right for max RPM?? Most tachs & speedo's are accurate +/- 10% ( I've slept since doing Tuckers Cyclone & I'm old & my note keeping skills are almost none existent )
What I like to see is when you jump on the throttle from a dead stop is the tach jump up to the engines max RPM once the clutch engages, then once your rolling & the track isn't spinning anymore then the tach MIGHT fall back about 500 RPM but then as you gain speed then the engine should climb back to your max RPM.
My preference is I like to see an engine idle at around 3500 to 4000 especially with duel carbs they run a lot crisper then & this also eliminates most of the low end bog.
It's a good Idea to take a magic marker & draw a line from top to bottom on both clutchs then go out & do some test runs & some WOT/top end speeds also. then stop & look how much of the lines are wiped off of both clutches, this will tell you a lot, If both lines are gone or nearly gone then your dialed in pretty good..

Grumpy
still on Chris's computer until next week

[Viktory2k1]

Thank you, I will try that. Once I put the 48 new studs in I will have 96. I dont think there will be any spinning of track, just tear the belt apart. This is a 77 cyclone 440 fan cooled single carbed sled. Sled does accelerate much faster but cant really test top end due to handling issues(ski mounting hardware is junk). I am not going to mess with the weights yet due to I am not an expert it that area. Mine idles at around 3000 rpm and not sure if I want to turn it up yet. Someone one here told me not to put studs on outer bands of track and I can't remember why. I just don't want to harm motor by over reving.
Vic

[harleysportster]

The thought of not studding the outer track bands is that it interfers with steering. There is also an old school of thought, 1 stud per horse power. 48 studs should be enough. I don't know how many studs is too many but too many studs causes more drag on the driveline. The Cyclone engine should idle between 1800 to 2400 rpm.

[Viktory2k1]

Ok
I have to find room for 48 more studs. I know sled will tend to want to push forward but we'll see haw bad. I still cant find the right ski mounting hardware. Tons of slop on skis and anything before spindles is good. After spindles is either worn out or wrong and I swear this thing should have multi-leaf springs and mine is mono-leaf. Also I can't find shocks.


Could use some decals also.

[fastl82vette]

My sprintfire I picked up this year has a ski with a lot of slop in it. I haven't tore into it yet to see what I need to fix it. My guess would be to take the hardware off the other ski and head to the hardware store to try and match it.