Serious clutching issue

[triple650]

allright guys i have a serious problem with my clutching, first off sled is a 2010 crossfire 800 with a power claw on and jaws can. I got a primary rebuilt for it, within 5 miles the primary was completely destroyed. So i figured either the primary wasnt rebuilt properly or it was the belt i was using. I put a brand new Cat clutch on with the same belt that i had that ruined the first clutch. Gates 39c4455 which isnt exactly the same size, and its doing the same thing.

So i put a new cat belt on and it seems to run alot smoother but im getting major heat off the belt and clutches, plus its still leaving this black line mid way up my clutch. Only thing that could be wrong is the motor mounts, the secondary is a brand new bdx heavy duty secondary with the bdx adjustable spring tension helix. I just dont know what to do anymore so if any of you have seen this before please give me some advice.

As of right now,

-new stock primary
-new secondary 36 degree helix/stock orange spring
-60/60 gearing
-new stock 060 cat belt
- 2900 miles on sled



the pics ill post with this are the pics of the rebuilt primary that was destroyed and then the pics of what my motor mount looks like along with the new cat primary/ belt. thanks alot

 

[triple650]

Also I should add, that before I installed the rebuilt clutch I had only ridden the sled twice this year. First time it ran awsome, second time it was mild and grenaded a not so used belt at full throttle. My old primary had 1600 miles on it and the secondary was original except for rollers helix and spring. So maybe the mounts got bad over the summer I'm not sure. But from the information I've posted I hope someone can help me.

 

[m8magicandmystery]

Also I grenaded a not so used belt at full throttle. .

check your crank run-out..

 

[m8magicandmystery]

plus its still leaving this black line mid way up my clutch.

jmo..but that indicates to me your primary is not overcoming your secondary.




"bdx adjustable spring tension helix"

so less secondary tension /helix start angle or weight ramp or spring primary mid rate issues..??

 

[mbcat]

Either you're down on power from apv issues or chipped reeds etc or your sec clutch is binding. Clean valves and check cables, check for chipped reeds. Run engine on stand and watch if engine moves all over(ruined mounts).

 

[Rixster]

Your just slipping in the primary. You need more weight or less spring in the primary. Or your secondary is way to stiff a spring or it is binding up for some reason.
I really hope that is your old secondary in the pics because those rollers and weights are TOAST !!

 

[triple650]

It has nothing to do with my apv or reeds, I just put new reeds in and the valves are good. I'm hitting peak rpm no problem, cycles through rpm no problem. The pictures of the absolutly destroyed primary are of the primary that was supposed to be "rebuilt" and it lasted 5 miles of not even hard riding.

Now when I start the machine it vibrates a lot, like the engine I find moves a lot on idle. What I noticed also is when I grenaded the belt on my old clutches (old primary/old secondary) it blew the belt when it was mid way up the primary. It looks like the belt was gouging out aluminum so there was clearly something wrong before I went ahead and changed both clutches. Now let's say all 3 clutch side mounts are toast and the engine is torqueing really bad, would it cause slippage? Or marks like it's doing mid way? It has to be that I can move the engine with a screw driver lol.

 

[fishhunter18]

Mine does that last year. It was the rear right mount bracket completely broken!

 

[diggerdown]

First thing is checking your clutching balance, make sure it is proven set up between springs, weights and helix. The pics look like an orange spring in the primary? I don't know who makes that one but make sure you are in the 120/285 range. Make sure you don't have the pins too tight. I always recommend going back to factory clutching and then work out from there, especially when you are have issues like yours. Make sure the secondary is not binding, BDX has had some cases in the past with too tight of fit in their bushings. I would replace the motor mounts after I checked the crank run-out. They probably are getting shot by now but I do think you have binding issue going on.

 

[triple650]

The spring/weight/helix combo is stock. Stock yellow/white cat primary spring, stock 67 gram weights. I know the weight pins aren't too tight cause I installed them making sure they wouldn't be. The helix is the stock m8 helix angle, I had a 40 degree in the stock secondary so this should actually be an improvement. How would I go about checking crank runout? And I think my best bet is to replace the entire motor mount plate. I think it's just three nuts on each mount and then 4 bolts near the crank. Like I said I can move the engine with a screw driver and by the pic you can clearly see the motor mount is toast.

I just wanna make sure it's not something else, I don't think the secondary is binding because I can hit 80 mph no problem on a packed trail. So my guess is the engine is torquing extremely bad causing it to slip and make those black marks? I'm really not sure.

 

[Sledbrain2]

I would replace the motor mount plate, easy job, the bolt around the shaft are locktighted so you may have to apply heat. I would just get the Cat replacement verse just replacing the pucks.

 

[madsledder]

Make sure to check the front mount and the stator side mount. Did you align the clutches after you baught the new ones? Quite often it is the stator side mount that is shot.

 

[backcountryislife]

His clutching combo is pretty basic... the adjustable helix is backed all the way out, and he's still pulling tons of RPM.

I've been trying to figure out what would cause this for days... I find it hard to believe that the motor mount being off could destroy a primary Erik JUST rebuilt (it was my primary that had simply trashed a roller pretty early... not many miles on it, so not some junker) then to see it do the same to another one confuses the heck out of me.


Justin, have you checked the RIGHT side motor mount?


Btw, crank runout is checking for "wobble" at crank stub essentially. Pull primary & put a dial indicator on crank, this will show if the crank is bent.

That said... I don't see how that would do this either.

 

[triple650]

Just to give an update I'm waiting for my new mounts to come in and then I'll be able to test it out. I really hope it solves the problem, and I will check crank runout also. I'll keep you all updated

 

[Rixster]

If you are building rubber on either clutch that means the belt is slipping in that clutch. If it is slipping in the primary you either are to light in your weights or your spring is to stiff. I am not saying that a bad motor mount isn't making this issue worse, but it isn't your only problem. Clutch heat is a direct result of the belt slipping. A certain amount of clutch heat is normal, (100 to 120 range) but excessive heat is a BAD thing. It will quickly destroy the bushings, and rollers in your new clutch.

 

[triple650]

If you are building rubber on either clutch that means the belt is slipping in that clutch. If it is slipping in the primary you either are to light in your weights or your spring is to stiff. I am not saying that a bad motor mount isn't making this issue worse, but it isn't your only problem. Clutch heat is a direct result of the belt slipping. A certain amount of clutch heat is normal, (100 to 120 range) but excessive heat is a BAD thing. It will quickly destroy the bushings, and rollers in your new clutch.

I know but it's stock clutching, I never had this issue before. So it doesn't make sense. But my old clutch blew the belt mid way up the clutch, so the problem is something not clutch related. I'll have to wait and see.

 

[Rixster]

I know but it's stock clutching, I never had this issue before. So it doesn't make sense. But my old clutch blew the belt mid way up the clutch, so the problem is something not clutch related. I'll have to wait and see.

Hopefully your motor mount fixes it. If not, and your confident that your clutching is good you probably should get the crank run out checked. Either way you may want to have the crank trued over the summer. I do mine every time I do a rebuild. If you have a good machine shop locally then its pretty cheap. The guys I use charge me $20 to true mine. It also give you a chance to really check your crank bearings and your water pump shaft.

 

[mbcat]

jmo..but that indicates to me your primary is not overcoming your secondary.




"bdx adjustable spring tension helix"

so less secondary tension /helix start angle or weight ramp or spring primary mid rate issues..??

Bingo! tight, new bdx sec and lacking primary weight.

 

[triple650]

Bingo! tight, new bdx sec and lacking primary weight.

It's not lack of weight, it's stock clutching I ran it last year with a stock clutching setup. There's no way the secondary is producing to much tension since it has the stock spring. It's not like I have a completely new spring/weight combo. I should have the mounts today and we'll see what happens.

And as far as a "local" machine shop trueing my crank all I gotta say is "LOL" people around here don't know poop. I'd have to send it away for that.... I'll update you guys when I'm done

 

[thefindian]

Start it up with the hood open and look at the clutch when its idling if the crank is bent you will see the clutch wobble and the motor will shake I seen a clutch grenade last year and it bent the crankshaft I put a dial indicator on it and it was 60 thousands out.