'09 M8 bogs/dies after a long WOT climb.

MI1M600EFI · Feb 9, 2011

'09 M8 bogs/dies when going to throttle

<edited to update status>

Ok, i was blaming the throttle safety switch, but I clipped one of the wires to the switch and it still did this yesterday.

After high throttle operation, if I come out of the throttle for a second and get back in it gently, the engine dies out, just like the throttle safety switch is telling it not to go. If I get off the throttle, it will idle, and if I let it idle for a few more seconds, it runs just fine when I throttle it.

It does it at the worst times, like when I've just climbed something and trying to get turned around, and bla... blaaaaa... Idle.... Then it goes. Luckily the snow was rather set up and it never got me stuck, but I could see how I'd be screwed in deep powder.

The sled is bone stock. Plugs looked OK when I checked them after the last ride with the SLP can, and I tossed the stock can back on it for this last ride.

Any ideas? Anyone else notice the same thing? I'm wondering about the fuel pressure perhaps, but not sure how that would do this w/o running lean all the time, or rich all the time.

I have messed with all the wiring harnesses, and they all seem fine. It never does this unless I'm bounding up something, at higher load. I messed with it across the flats yesterday and never got so much as a hiccup...

Strange that it will idle fine, but throttle kills it, then it's fine again with throttle after a bit of idling.

?????????

MI1M600EFI · Oct 22, 2015

Just a followup since I figured this out finally... Two things: First, when the belt gets worn too skinny, it seems to cause my sled to bog down low occasionally. I've started putting a new belt on when it first happens, and I use the old belt as the spare then. Seems to have cured the problem twice now.

Second, I had a stalling issue at times when I'd come off the throttle from just cruzing along. I finally realized that when it didn't stall, I could hear a "bang" as the primary dropped back apart. Turns out as the clutch rollers wear into the weights on the primary, they start hanging up, and the clutch gets stuck together. Time for new weights.

If you have either issue, those are my findings. Not sure why the engine seems so easy to bog out when the belt is a little thin, but a new belt has resolved it twice.
YMMV
Chris

2010Catman · Oct 24, 2015

Sounds like you may have the driven clutch hanging up up the back shift. Check the rollers and movement.

Rixster · Oct 25, 2015

MI1M600EFI said:
Just a followup since I figured this out finally... Two things: First, when the belt gets worn too skinny, it seems to cause my sled to bog down low occasionally. I've started putting a new belt on when it first happens, and I use the old belt as the spare then. Seems to have cured the problem twice now.

Second, I had a stalling issue at times when I'd come off the throttle from just cruzing along. I finally realized that when it didn't stall, I could hear a "bang" as the primary dropped back apart. Turns out as the clutch rollers wear into the weights on the primary, they start hanging up, and the clutch gets stuck together. Time for new weights.

If you have either issue, those are my findings. Not sure why the engine seems so easy to bog out when the belt is a little thin, but a new belt has resolved it twice.
YMMV
Chris

If your weights are trashed its your rollers that are bad, If your sled has over 2000 miles it is time for a new set of clutches. The secondary is most likely worn out and it sounds like the rollers in your primary are smoked also.

MI1M600EFI · Nov 28, 2015

I don't buy into needing new clutches every 2000 miles... I don't ride that hard, so mine last longer anyway, and the parts that wear first are replaceable. There's no way I'm shelling out $1000 for new clutches when mine only need $100 worth of small parts... Unfortunately, Cat prefers that you buy the complete clutches, so they don't even list replacement parts like pins and rollers anymore... I have p/n's from when they did, so I can still order them.
I used cat parts before, but next time I'm going to try the "improved" rollers from TPI.

I burnish the surfaces of both clutches with scotchbrite whenever they start looking shiny or have evidence of belt smears on them. That seems to be keeping them quite nice. I'll just keep maintaining/rebuilding them until I can't... But I haven't gotten there yet...

Also, reading a bit more, I'm betting I may have a sticking oil pump too... This sled has always been an oil hog, and seems to be getting worse. I'm going to do the O-ring thing before any riding this year. Can't hurt, and might even help!

WyoBoy1000 · Nov 28, 2015

MI1M600EFI said:
I don't buy into needing new clutches every 2000 miles... I don't ride that hard, so mine last longer anyway, and the parts that wear first are replaceable. There's no way I'm shelling out $1000 for new clutches when mine only need $100 worth of small parts... Unfortunately, Cat prefers that you buy the complete clutches, so they don't even list replacement parts like pins and rollers anymore... I have p/n's from when they did, so I can still order them.
I used cat parts before, but next time I'm going to try the "improved" rollers from TPI.

I burnish the surfaces of both clutches with scotchbrite whenever they start looking shiny or have evidence of belt smears on them. That seems to be keeping them quite nice. I'll just keep maintaining/rebuilding them until I can't... But I haven't gotten there yet...

Also, reading a bit more, I'm betting I may have a sticking oil pump too... This sled has always been an oil hog, and seems to be getting worse. I'm going to do the O-ring thing before any riding this year. Can't hurt, and might even help!

Weights don't wear out unless you have a bad roller!! if you put new weight in where the old ones have been damaged then it will only be a ride or 2 before it ruins those weights too.

When you have it apart, put your finger on the roller and push on it while rolling it back and forth. If it isn't really smooth or has any odd feel to it then it is bad.

Once they start to stick the next thing is the spider will break.

My last clutch was gone at 600miles. I've never not seen a clutch in need of replacement at 2000miles on any sled. Still worked but they where wore out of spec

Thunder101 · Nov 28, 2015

Ya it sure sounds like you have a bad roller.

MI1M600EFI · Nov 28, 2015

Yup. I check rollers and agree that bad rollers are what cause weights to wear. Probably explains why replacing a weight only fixed for a short time. Then it got pins, rollers, and weights.

summ8rmk · Nov 28, 2015

I find it funny that the original post was un answered for 4yrs and 8months. Now that the problem is solved, we have 6 replys in one month.

GS6

WyoBoy1000 · Nov 29, 2015

summ8rmk said:
I find it funny that the original post was un answered for 4yrs and 8months. Now that the problem is solved, we have 6 replys in one month.

GS6

Lol, didn't even look at the date. Wonder how long it held out. Maybe it wasn't the roller

MI1M600EFI · Nov 30, 2015

I thought it was sad... I would have loved some help with this four years ago...

It seems my sled is REALLY picky about belt width, or deflection, so with a used (narrow) belt, it likes to bog out when you try to take off.

Per my second post, the clutch issue was not the cause of my bogging, but rather stalling as I coasted. If I got back on the gas, it would occasionally bog a bit though. This engine will not make power below 3500rpm...

I bought the sled with ~2000 miles on it. Put another ~1000 on it and it flat spotted a weight, which I replaced. Several rides later, it flat spotted again, and I found a bad roller bushing, which I'm sure was bad to begin with, so I replaced weights, pins, and rollers. I'm hoping it'll last another ~3000 miles before I need to rebuild it again... If I make it that far...

WyoBoy1000 · Nov 30, 2015

When you say narrow belt, just how narrow are you talking? If one of my belts gets even 1/32 wore down its garbage to me.

What turbo kit is it?

Do you check the deflection, even if its worn a little if you adjust the deflection right it wont make a difference until it is so worn out you can't adjust it anymore.

What is the clutching setup, whos clutch weights and what helix?

MI1M600EFI · Dec 1, 2015

Narrow is probably 1/32 under width... I have the secondary shimmed so it sits just under 1/8" above the sheaves normally. By the time it wears down mostly into the sheaves, I start to get occasional bogging. I tried running another shim to get rid of some deflection and move the belt up, but it quickly wore again,so it was probably already done.

Completely stock sled, no turbo.

As I understand it, deflection is adjusted with shims on the secondary. I adjust it to get about 1/8" of belt sticking out the top of the sheaves. It usually squeals a little at idle at 1/8", so I aim for just under that, actually.

Cat clutch weights per the chart on the sled for altitude, or within 1/2 gram anyway. Stock helix. No complaints on clutching for how I ride.

M7 Aerocharger Boosted · Dec 3, 2015

Belt Deflection

You do want the cord line on the belt above the secondary. If it is squealing it is just barely too tight. Arctic cat and BDX sells different thicknesses of shims or sand some down to thickness. Clean your power valves if you haven't already. Sticking power valves have similar symptoms. Very worn rollers in the secondary also have symptoms like this. (Secondary slow to shift back to a lower gear) Sticking oil pump try brake clean worked on mine.

mbcat · Dec 3, 2015

Get your hub & bushing replaced in secondary clutch by Mel @ Formula x-1

Torkk · Dec 3, 2015

MI1M600EFI said:
I don't buy into needing new clutches every 2000 miles... I don't ride that hard, so mine last longer anyway, and the parts that wear first are replaceable. There's no way I'm shelling out $1000 for new clutches when mine only need $100 worth of small parts... Unfortunately, Cat prefers that you buy the complete clutches, so they don't even list replacement parts like pins and rollers anymore... I have p/n's from when they did, so I can still order them.
I used cat parts before, but next time I'm going to try the "improved" rollers from TPI.

I burnish the surfaces of both clutches with scotchbrite whenever they start looking shiny or have evidence of belt smears on them. That seems to be keeping them quite nice. I'll just keep maintaining/rebuilding them until I can't... But I haven't gotten there yet...

Also, reading a bit more, I'm betting I may have a sticking oil pump too... This sled has always been an oil hog, and seems to be getting worse. I'm going to do the O-ring thing before any riding this year. Can't hurt, and might even help!

Could you post those p/n? Might be helpful to some of us having similar symptoms.

MI1M600EFI · Dec 4, 2015

Torkk said:
Could you post those p/n? Might be helpful to some of us having similar symptoms.

Pins: 0646-270
Rollers: 0746-067
Roller Bushings: 0646-272
Roller thrust washers: 0646-327
Torque Buttons: 0646-293

If you wreck the threads in the spider getting it off, a new one complete with all the above already installed is P/N 0746-118, and isn't that much more expensive at ~$125. (Only fits 2009 and older sleds with SAE threads. Cat switched to metric threads for 2010.)

EDIT: Scratch that... Just buy the spider... Cat has raised the price on all the piece parts to the tune of ~$230 total. The complete spider is WAY cheaper.

I got these p/n's from an '00 ZRT800, and I've used them in the older 9-tower clutch of my '04 600, as well as the newer 6-tower clutch in my '09 M8.

To disassemble the clutch, you need a spider removal tool, some way of holding the clutch while you REALLY torque on the tool, a torch to heat it and release the locktite, and ideally some locktite for re-assembly, at least on sleds with engine reverse.

Next time I do the clutch, I'm putting in a pin/roller kit from Thunder Products, p/n TSK-650. Fettbros also sell a more complete kit with the buttons, p/n ACASK1, and a complete kit with ALL the bushing in the clutch as well, p/n ACCRK1.

Chris

mbcat · Dec 5, 2015

Billet spider from thunder, Fett or others is the way to go

Search

'09 M8 bogs/dies after a long WOT climb.

MI1M600EFI

Well-known member

MI1M600EFI

Well-known member

2010Catman

Free Member

Rixster

Well-known member

MI1M600EFI

Well-known member

WyoBoy1000

Well-known member

Thunder101

Well-known member

MI1M600EFI

Well-known member

summ8rmk

Most handsome

WyoBoy1000

Well-known member

MI1M600EFI

Well-known member

WyoBoy1000

Well-known member

MI1M600EFI

Well-known member

M7 Aerocharger Boosted

Free Member

mbcat

Free Member

Torkk

Free Member

MI1M600EFI

Well-known member

mbcat

Free Member

Similar threads