I have a 1998 ski doo summit 670 I love the sled it does great in the mountains, but it really eats up the belts. I am not sure what I need to do, I was wondering if worn clutch components can cause this affect. I also need to know if it is likely to be the primary clutch or the secondary clutch. Could a dirty, stiff secondary clutch be the problem? Thanks for any help!
ski doo clutching
- Thread starter summit670
- Start date
Ancient Sledder
Active VIP Member
Check your motor mounts. Take both clutches apart. Replaced all worn parts. Replace both springs. Set the secondary spring pressure. Buy and use a clutch aligning tool. Check your center to center measurement of the clutch spacing. Buy a new belt and wash it, then break it in properly. 15 to 20 miles of gentle use with no full throttle. Then you should be good for at least 2 seasons on the clutches and get 1 season out of the belt. This is what I do and I have no troubles at all.:d
mxz sledhead
Active VIP Member
Clutching alignment is one of the most important things you can do to a sled
relative easy thing to do with proper tool/gauges .Clutch guage cost $20
at Royal distribution about and 1hour for frist time doing it.I hope this helps
relative easy thing to do with proper tool/gauges .Clutch guage cost $20
at Royal distribution about and 1hour for frist time doing it.I hope this helps
- Thread starter
- #4
This is quite a help, but I have one more question. When i took apart the secondary clutch to clean it I put is together, but did not wind it up properly I was wondering if this could be part of my problem. So there was not much spring power to rewind the clutch when it closed. Also the clutch was all gummed up, so It was impossible to open by hand. could this wear on the belt faster? Thanks much.
s/b tech
Active member
The secondary clutch for this sled should have aprox 15lbs of sring preload.
You should not easily be able to pull the two sheaves apart. If this is happening then there will not be enough side pressure on the belt causing it to slip and take out the belt.
You should not easily be able to pull the two sheaves apart. If this is happening then there will not be enough side pressure on the belt causing it to slip and take out the belt.
Ancient Sledder
Active VIP Member
This is quite a help, but I have one more question. When i took apart the secondary clutch to clean it I put is together, but did not wind it up properly I was wondering if this could be part of my problem. So there was not much spring power to rewind the clutch when it closed. Also the clutch was all gummed up, so It was impossible to open by hand. could this wear on the belt faster? Thanks much.
You betcha. That is the secondary tension. On mine I know it is 16-18 pounds, but I don't know the spec for a 670. Somebody on here must know.
Same spec on the 670,
but I'd recommend replacing the springs on both the clutch and driven any time they're more than 3 years old.
The best performance gains to be had on the old girls is with fresh springs ($20 each+-) and clean clutches.
Improper spring tension and sagged-out springs are also very hard on belts.
Hope this helps.....
but I'd recommend replacing the springs on both the clutch and driven any time they're more than 3 years old.
The best performance gains to be had on the old girls is with fresh springs ($20 each+-) and clean clutches.
Improper spring tension and sagged-out springs are also very hard on belts.
Hope this helps.....
my mod
Active VIP Member
- Joined
- Oct 19, 2008
- Messages
- 1,188
- Reaction score
- 706
If you had them apart once and did not put them together right you would have serious heat in the clutches. Most likely engine needs alignment. There is also a black puck that braces the engine. That might be gone. Cleaning clutches and repacing springs never hurt.
Spec is 13lbs of pull from static and about 19lbs at about 2" movement.
Get a fish scale and hook it to the moveable side. Pull the clutch and the sliding half should begin to move at about 13lbs of force. When it has moved 2" of rotation the scale, the scale should read about 19lbs. If you get it anywhere in the 16-18lb range it will be fine unless you have the perfect scale and can get that accurate but you won't notice a difference of 2-3 lbs IMO.
Check alignment and spacing washers on the secondary clutch. You want your secondary to be "floating" on the shaft (able to move back and forth about 1/4"). If your motor was really boggy (like it was trying to start out in 3rd gear) then the secondary may have been the problem. If it pulled away from a dead stop pretty good, alignment might be the issue.
Your original comment was if a sticking secondary could be the problem. Usually a sticking secondary that will not upshift, what will happen is your motor revs really high but the sled won't go any faster. This is the easiest way to diagnose if your secondary is wound to tight as well. You can rev it and it just doesn't go any faster - secondary is not shifting out and allowing the belt to ride higher in the primary.
Hope that helps.
- Thread starter
- #10
my mod
Active VIP Member
- Joined
- Oct 19, 2008
- Messages
- 1,188
- Reaction score
- 706
going by memory now, but 50/47 helix set on C6 seems to be the right setting. I went to 300 ramps in the primary and that really woke it up as well, but you might have to change the pin weight slightly, I can't remember if I did or not.
Not sure what my helix is but my 98 670 secondary is set to b6
look forward to hearing how you make out I have the same sled and the same problem. I just can't aford to do anything to my sled right now. Best of luck.
also I found my secondary almost impossiable to pull open by myself. it took two of us after cleaning up all the rust.
DRD
Active VIP Member
Another thing you might want to try is throwing the Doo secondary in the garbage and put a Cat roller on it. Also run the later "027" belt from the ZX chassis.
sledderdoc
Super Senior Member
There is also a guy on Doo Talk that sells a washer you put on the secondary shaft that allows the secondary to float. That may help but in reading the thread it does sound like you really need to clean yours. 
:d Also some really good advice on here so far. I would agree with most.
:d Also some really good advice on here so far. I would agree with most.
Ancient Sledder
Active VIP Member
I took off my Doo secondary and replaced it with a Team. The original one was working fine, but what a difference the Team makes.
Summit600Mtn
Member
Try terrin out both clutchs and checking them out or try buying a used one there not that expensive used
what kind of diffrence did you notice ? how much did the clutch cost? I may have to try doing the same to mine.
Ancient Sledder
Active VIP Member
The backshift is incredible. I ride the mountains in Northern BC with the old Summit. If you have to back off on a climb to avoid something in your way, when you throttle up again the hit is instant. This is with a stock engine,pipe and muffler. I was lucky and got it for free from my brother [Ron Dun, on this site]after he upgraded to an RT1000. He said it was 6 or 700 brand new.
Similar threads
