2008 800r Clutching

[saskryan]

I've got a 2008 MXZ 800 and I'm trying to figure out why I'm not getting enough speed out of it. I can barely pull 80mph at near full revs. I've got 441 ramps with 21.8g weights from a dalton pin kit on clicker 5 and I get about 8400 out of the hole and then revs come down to around 7600 or lower. How do I get higher revs when full out without over revving off the line?

 

[duck]

I've got a 2008 MXZ 800 and I'm trying to figure out why I'm not getting enough speed out of it. I can barely pull 80mph at near full revs. I've got 441 ramps with 21.8g weights from a dalton pin kit on clicker 5 and I get about 8400 out of the hole and then revs come down to around 7600 or lower. How do I get higher revs when full out without over revving off the line?

What helix you running? What belt? 377 is the benchmark. Run a new one. I would start out by checking your rollers as I would bet one or two are worn out, maybe even all three. Sounds like the secondary spring needs more tension or is sagged and is upshifting too fast resulting in a faster/higher range before the primary shifts out. In other words, the secondary is getting ahead of the primary. The belt is dropping too deep in the secondary resulting in your loss of rpm. Once the secondary has more tension it will want to keep the belt higher in the secondary and keep the rpm's up. Once you have that sorted out then you can look at the primary spring. Of course this is provided your rollers are still good. Both springs should be checked for tension or just buy 2 new stock ones. I could never spin 21.8 grams in my 800R......I'm at 17 in the renegade....

 

[saskryan]

I actually just rebuilt the primary 200 miles ago. New rollers, pins, and ramps. Cleaned the whole thing up. Can't remember for the life of me what the spring was. I just bought this sled and I'm new to doo's. I have great engagement, basically can cat walk for 1/2 mile if I wanted to (136" track 2"). But the top end is definitely lacking.

 

[saskryan]

When you said rollers were you talking the secondary ones?

 

[duck]

When you said rollers were you talking the secondary ones?

Primary.....

 

[duck]

I actually just rebuilt the primary 200 miles ago. New rollers, pins, and ramps. Cleaned the whole thing up. Can't remember for the life of me what the spring was. I just bought this sled and I'm new to doo's. I have great engagement, basically can cat walk for 1/2 mile if I wanted to (136" track 2"). But the top end is definitely lacking.

What belt? If its new and a 377 then we can rule that out. Like I mentioned, I cannot run that much pin weight. I think stock was 18 grams.... Mine needed 17 to run on clicker 3 at 8300 rpm. The tach reads 100 rpm high.

 

[saskryan]

When I rebuilt the primary it had 25g weights in it so I went with the biggest ones that were in my new pin kit.

 

[duck]

I wonder what gearing?

 

[duck]

When I rebuilt the primary it had 25g weights in it so I went with the biggest ones that were in my new pin kit.

To run that much pin weight, you might need more spring in the primary..... rpm will suffer with that much pin weight

 

[saskryan]

It has a pretty big spring in it. It's grey and is at least an inch longer than stock spring and takes much more to compress.

 

[duck]

It has a pretty big spring in it. It's grey and is at least an inch longer than stock spring and takes much more to compress.

Stock primary spring is 115 mm long and a 160/290, sounds like yours is probably 135 mm long and 240/370. If I was you, I would reduce the pin weight to 18-19 grams and try it. Run it on clicker 3. Sounds like it had some sort of clutch kit. I talked with dynamoe/joe and he quit making the kits for renegade style sleds. My clutching is stock and it works well.

You can doo some research here as well...... Snowmobile Clutch Kits, Dynamo Joe, mxzx revzone

You never mentioned what belt your running but if its not a 377, your behind the gun already.

 

[saskryan]

Thanks for all the info, so many different factors involved in clutching these things.

 

[duck]

Thanks for all the info, so many different factors involved in clutching these things.

Yes, change one thing and it all can go south in a big hurry. Personally, I would go back to stock, your 441 ramps are fine. Get a new 377 belt, run 18 grams pin weight. A number 415034900 primary spring and a number 417127062 secondary spring which may already be there. Clicker 3 and see what happens. Clutch heat will also be a factor. I have 5400 km's on mine and just put a new belt on this year. Belt makes a big difference cause over the years I found I had to go to clicker 4 but once I put the new one on, it was hitting the rev limiter this year and back to clicker 3. Mine will run a consistant 180 kmh on hardpack all day long at 8250-8300. Clicker 5 in the mountains at 7000-8000' and she runs 8300.

here is the brp parts look up website where you can find all the part numbers...... http://parts.ski-doo.com/Index.aspx?s1=ilbp1k9btkj6fr8kna54pguqg3&catalog_id=1&siteid=1

just click on your model year and then go from there.....

 

[Sask Sledder]

Go to clicker 3 and remove maybe 1.5 grams.

The higher the clicker the faster you will get yiur rpms, but the faster they will drift.

Sent from my SGH-I747M using Tapatalk 2

 

[saskryan]

Dropped to 17.5 grams, and went to clicker 3. At -20 it was running awesome, but running it at -8 it sucked. I just pulled the secondary off and dropped it off to be rebuilt. Hopefully that makes some difference. I think my next step is gonna be changing out the primary spring and putting a new bushing in.

 

[Ski-Dick]

I was having very similar symptoms with my 07, revs would peak and then drop to 7,200 rpm off the line. It actually turned out to be a RAVE issue. The arm on the side of the lower exhaust valve broke off. May be worth a check to ensure your RAVE's are functioning properly.