Sled is a 2019 skidoo 850 with a low boost bd sidekick. Sled holds 8k all day long on flat and mild hills but as soon as I get into steeper terrain it seems to drop down to roughly 7600 rpm. Primary has zrp .90 weights with 4.5 grams added in each. They are loaded with 2 magnets in the heel, 1.5 in the mid and 1 in the tip. Secondary is stock as bd claims they don't mess with them. I weight roughly 250 lbs ready to ride. Riding between 6500-8500 feet. Track is a 165 3 inch. I don't know much about clutching but I feel that it's not backshifting properly. A few others have suggested pulling weight out of the primary while others suggest putting a heavier spring in the secondary. Looking for advice from those of you that know these machines and possibly a good recommendation on what spring to go with for the secondary. Thanks guys!
19 skidoo 850 bd sidekick clutching question.
- Thread starter Tyhoskins16
- Start date
A great guy to talk to is Big John over at Sled Head Racing.
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Yea I sent him an email so I'm assuming he will get back to me next week
Texting him or messenger the SHR page on Facebook is honestly the best way to get ahold of him in my opinion. Been using him for quite a few years I just text him at a reasonable time during the day and he usually text back in an hour or two. I haven’t had good luck emailing him so if he doesn’t get back to you in a few days I would just text or call.
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Hi Tyler.
Know what the primary clutch spring is. What are the forces of the primary clutch spring?
Take the primary spring end force and raise it 30 pounds.
Example for lack of better numbers....
IF have engine speed drifting with a xxx/350, THEN change to a xxx/380
Raising the primary spring by 30 pound end force will add about 15 pounds in the midrange at the track speed you are having drifting rpms.
IF still have drifting rpms (low) but not as low as before, THEN go to xxx/400 pounds. That will make about 25 pounds spring force in the midrange at the track speed you are having drifting rpms
IF you have the blue secondary spring 157/230, THEN change over to at least the Black low elevation 850 spring 157/303. Take the secondary spring final force and raise it.
You're going from xxx/230 to xxx/303 and will raise 35 (estimated) pounds at the problem track speed and that should help keep engine speed from falling less than 400 rpms.
What you are trying to do is, at-the-track-speed where the engine speed starts to lower, right there, you want to raise either the primary or secondary spring force or both.
Sled pulls 8k all day long on flat to mild hills
steep hill the rpms drop to around 7600
Know what the primary clutch spring is. What are the forces of the primary clutch spring?
Take the primary spring end force and raise it 30 pounds.
Example for lack of better numbers....
IF have engine speed drifting with a xxx/350, THEN change to a xxx/380
Raising the primary spring by 30 pound end force will add about 15 pounds in the midrange at the track speed you are having drifting rpms.
IF still have drifting rpms (low) but not as low as before, THEN go to xxx/400 pounds. That will make about 25 pounds spring force in the midrange at the track speed you are having drifting rpms
IF you have the blue secondary spring 157/230, THEN change over to at least the Black low elevation 850 spring 157/303. Take the secondary spring final force and raise it.
You're going from xxx/230 to xxx/303 and will raise 35 (estimated) pounds at the problem track speed and that should help keep engine speed from falling less than 400 rpms.
What you are trying to do is, at-the-track-speed where the engine speed starts to lower, right there, you want to raise either the primary or secondary spring force or both.
You emailed me
2 magnets in the heel 1.5 in mid and 1 in the tip
steep hill the rpms drop to around 7600
then.....change to 2 and go test. Change to 3 and go test.
