boggy either clutch or carbs - Snowmobile Forum: Your #1 Snowmobile Forum

macro · 01-23-2006, 03:44 PM

This might be a little long, so I appoligize in advance. Here is the story. My cat ext 580z has been always known to be boggy on the low end then all of a sudden after 5000rpm it starts to really scream, and sounds amaizing!!! but from engagement around 3100 rpm until about 4500 5000 the sled is boggy and also theres an insane loud resonation sound. it really gets to the ears, but when you open the gas it clears up around the higher rpms. Yesterday, on sunday, I went with my friends up north riding and we did some nice trails. I also played with my carbs before. What I did a few days before was set the mixture screw to one turn out they were before around 1 1/2 and almost 2 turns on the other carb before. After setting to one turn I went riding, but it was quite warm that day, around 0 celcius. I notice my sled acting boggy all around, really annoying, similar to the low end bog but all throught the rpm band. I got back and didnt touch it since. Then on sunday before leavng up north I changed both carbs to 1 1/2 turns. When we got up norht I started my sled but it just wouldnt stay idling while cold unless I play with the throttle, it was annoying and I was worried it was too lean so I brought both back to 1 turn out (after that it idled perfectly). We went for the day and the low end bog and a little high end was still there. But then all of a sudden while driving back I notice my engine running soo quiet, like no more low end resonation and then I started testing take offs and holy moly!!!!! the thing is insanely fast, I mean super smooth, rips from take off etc... I can hear both carbs opening up right off takeoff, 4000rpm I even think my engagemnt of the clutch started engaging higher, but I could be so wrong there. I really wasnt paying close attention. Everything seemed perfect, super quiet no low end resonation etc.. but then after crossing one of the lakes and getting a lot of speed like 80mph~ and slowing down the low end bog came back, but not fully. But after driving lighter for another 35 minutes the low end started to clear up again. Now here are my only two guesses. 1) my clutching. Either my primary is in need of rebuild (but supsedly it was redone recently, but to what extent is unknown, maybe just the one broken spring was replaced. Also my secondary clutch i notice when I end my days the belt sits about 2mm into the sheaves. 2) heating on the carbs, when its cold (first start up) the bog is soo bad I have to like play with the throttle while engine heats up cause it will not even rev up just wuuaaa wuuaaaa sound. And as I drive litely like no high speeds it slowly gets better to the point where the sled runs amaizing but after high speed ridng it begings to act boggy on the low end again. So my guess is with #2 is, maybe the heated carbs play a role with how the sled runs, and maybe theres a possibility that my electrical cricuit to the carb heaters dont work (cause my handle grips dont heat) so maybe after fast driving the cold hair will chill up the carbs again causing the boggy (this is such a guess and i'm sure the heated carbs is really just for preventing icing but I still just wanted to bring it up in case) I would really love to get my sled to run predictable because after finaly riding it when running smooth I know I want to stick with it. I couldnt beleive the 580 can rip out so well from the low end, also sounds sooo amaizing hearing both carbs opening up from low to high rpm.

mx and sled 41 · 01-23-2006, 04:49 PM

so your belt sits 2mm below the sheave? your belt is probably worn... change your belt and you should be good.

macro · 01-23-2006, 04:50 PM

the belt is brand new, and I also just got three new secondary clutch buttons/sliders

1sickcivic · 01-23-2006, 06:03 PM

your belt is suppose to sit just a little above.

macro · 01-23-2006, 09:57 PM

would 2mm maybe a little more sitting under the top of the sheaves be enough to cause low end bog? or load on the engine to make a loud annoying resonation sound ?

**RJ Gleason** · 01-23-2006, 10:30 PM

You need to have the secondary serviced, it sounds as if it is sticking open some after a high speed run and gradually works itself back after being babied for a while.

The carb heaters are independant of the circuit for the hand warmers.

My recommendation is to have both the clutch and the secondary cleaned.

It seems that you have the carbs set right.

catman_580 · 02-20-2006, 12:22 PM

your belt is suppose to sit an 1/8'' above your secondary clutch, not below it

macro · 03-06-2006, 01:43 PM

Well, I finally got my new plastic skis to fit, had to mod the spindles, I gave it to a friend to send to his machine shop at work. And also pulled my secondary clutch off. After taking it apart my friend noticed there was no preload, so we preloaded it, put it back together. Yesterday I took my baby out for a spin and holy waca waca moly!!!!! Its a new sled!!! Corners sweet with the camoplast skis, even on icy corners it just went through no problem, and the low end bog is gone!!!! the carbs might need synching, but wow, it rips !!!!! overall top speed is way up there. I can climb rather easily to 90 and I still felt more, unfortunately the trails were very bumpy, and I literally have zero shocks left. After yesterday I now know how my sled feels like when its set up better. I am so keeping this machine, even comparing to some newer sleds i've driven I preffer my cat.

96sport · 03-06-2006, 03:46 PM

Meow !

BC_Dan · 03-06-2006, 04:09 PM

Quote:

Originally posted by macro
. Yesterday I took my baby out for a spin and holy waca waca moly!!!!! Its a new sled!!!

Now, THERE's a term you don't see every day

Glad you got it figured out, I know how you feel.. those 580's run great when you get all the bugs out!

IndianRvrShiver · 03-06-2006, 06:23 PM

Another Happy ending!!

Many low end bogs are caused by bad cluth parts/belt as demonstrated in this case!! Good Job!!

**RJ Gleason** · 03-06-2006, 11:40 PM

Make me feel good when someone listens and then has great results. Have fun with your "new" sled.

macro · 03-08-2006, 06:04 PM

Last night I took my sled out again, and OMG it was even faster because the snow was really hard packed. This machine is a beast, I didnt think it was this fast. Unfortunately the weather is getting worse for sledding this week, and I fear I might not be able to ride again. How ever i'm way more motivated to start restoring my sled for the summer knowing how much better she rides with the new skis and fixed clutch. I cant wait to try with new bushings, bearings all around and shocks!!!!

96sport · 03-10-2006, 06:54 AM

and it still couldn't catch my 440