I have a 2003 RMK 800 144" that is completley stock. It seems to be not pulling the RPM's I would like it too. I think this problem is due to my helix because the sled use to have an slp single on it. I changed the weights and spring in the primary back to stock but I never did anything with the helix in the secondary which is an SLP 40-50-34. I did not check what spring is in it because I havent been able to take it apart yet but it is in the #2 hole. I have another SLP helix that is a 44-50-36 but I think that is steeper isn't it? I also have another spring that is yellow/orange. I am not real good with knowing how to fine tune these clutches yet so any help is appreciated! Also I am running this sled in SE Minn. so I am at low elevation.
Helix Question
- Thread starter Trevor83T
- Start date
If it used to have a slp single on it it may have been jetted up a little. not sure what you should have for that low an elevation, but its possible that your just running a little fat.
T
theultrarider
Well-known member
The helix should work just fine for you without the pipe. I too think you are just fat with the "factory spec" jetting. Try a set of 400's in it and see what happens. That is what we run in our stock motors in Alaska literally at sea level.
Age 17 with an 03 800.....nice. Enjoy every minute.
Tuning RPM with the secondary is not the place to start. The secondary helix spring combo is all about dialing in enough grip on the belt for your riding conditions to avoid slippage. Once the grip thing is figured out then turn your attention to RPM.
RPM is addressed at the primary. If you need a bit more RPM's at top end i would first try a primary spring with a higher finish rate. If you need more RPM through the entire shift then go with lighter wieghts.
this assumes clutches are clean, aligned and in proper working order and belt is in good shape. Throttle cable adjusted properly? Good cold air to the carbs at max throttle? In other words if you went to twins and airpods with prefilters then I would suspect a restricted flow of hot air isnt helping. Sounds though like you went back to stock pipe from SLP single......noise issues in MN?
I thinks its unlikly you are jetted too rich to impact top end max RPM.
Tuning RPM with the secondary is not the place to start. The secondary helix spring combo is all about dialing in enough grip on the belt for your riding conditions to avoid slippage. Once the grip thing is figured out then turn your attention to RPM.
RPM is addressed at the primary. If you need a bit more RPM's at top end i would first try a primary spring with a higher finish rate. If you need more RPM through the entire shift then go with lighter wieghts.
this assumes clutches are clean, aligned and in proper working order and belt is in good shape. Throttle cable adjusted properly? Good cold air to the carbs at max throttle? In other words if you went to twins and airpods with prefilters then I would suspect a restricted flow of hot air isnt helping. Sounds though like you went back to stock pipe from SLP single......noise issues in MN?
I thinks its unlikly you are jetted too rich to impact top end max RPM.
Last edited:
Thanks for the info! I have in 10-62 weights in the primary. When I first got the sled it had in 67's. Once I changed these it made a BIG difference so maybe I will try dropping another 1 or 2 sizes and see if that helps. As for getting rid of the pipe... My dad figured he needed it more than I did so he took it from me! But yes I do love the sled and I am lucky to have it, just wish I had some deeper pow and bigger hills to play on!
Oh man your dad is the worst! you better sneak into the shop when hes not looking and put that pipe back on 
If i remember right slp claimed it was a 13 hp gain on top and and lots of torque through the mid range. My 04 always ran good with the slp pipe anyways.
If i remember right slp claimed it was a 13 hp gain on top and and lots of torque through the mid range. My 04 always ran good with the slp pipe anyways.Stock helix is a 36 degree finish helix, if you switch it your R's will come up. Throw it in and see how it does. Since you already have it.
Stock it doesn't need a 34 degree helix
Stock it doesn't need a 34 degree helix
It will slightly change the amount of torque given back to the primary clutch on shifting. The tighter you change have the spring, the more force it will take for the primary to open it (slightly higher RPM once the secondary starts opening).
A general comparison is like shift points on a car, think of it like holding the shift longer before you change gears.
General rule of thumb, is that you have it as loose as you can without the belt slipping on it.
A general comparison is like shift points on a car, think of it like holding the shift longer before you change gears.
General rule of thumb, is that you have it as loose as you can without the belt slipping on it.
5 is tighter 1 is looser.
All the way thru.
The spring and helix are pretty much control how much load the belt has on the drivetrain.
When you punch it from a dead stop, you will see your RPM climb from engagment then go up to your shift RPM. This is pretty much controlled by the primary weights and their profile, but after that you will maintain your "shift RPM" as you accelerate speed. This is controlled by the combination of helix angle and torsonal spring pressure.
Now all of this is kind of different with a encapsilated roller clutch (Team style helix) but on a torsional spring clutch it is a basic theroy on how the cluth grabs the belt.
The spring and helix are pretty much control how much load the belt has on the drivetrain.
When you punch it from a dead stop, you will see your RPM climb from engagment then go up to your shift RPM. This is pretty much controlled by the primary weights and their profile, but after that you will maintain your "shift RPM" as you accelerate speed. This is controlled by the combination of helix angle and torsonal spring pressure.
Now all of this is kind of different with a encapsilated roller clutch (Team style helix) but on a torsional spring clutch it is a basic theroy on how the cluth grabs the belt.
