ski doo 583 ...need help

[MCharlebois]

just got it back from having it tuned up ,has ufo`s in the carbs ... i am getting backfiring/popping at wot... not every time but at least 80% of the time ... fresh rebuild... fresh fuel ... 98

any help will be appreciated

marcel

 

[zstroken]

Did it back fire before the UFO's were in the carb?? When was the last time it was running correctly? Why rebuilt. Sounds like a timing issue to me.

 

[WVanHemert]

583's are a rotary valve, I would check for rotary valve timing, how do the plugs look run it up to full throttle shutdown the engine with the kill switch and pull the plugs. That will usually tell you if it is fuel related or timing related.

 

[MCharlebois]

thanks for the replies... ufo`s have been in for 5 years . . sled was running great after rebuild last year... . rebuilt cause i got some water in the fuel and burned outsides of pistons ... thats what i was told, i saw pistons and yeah they were melted a little...

btw ... sled fouls plugs like crazy for a few years now??i have tryed a few different people but nobody seems to know... . everybody says carbs ... sled starts great . . i tried 8`s instead of 9`s(hotter)still fouled them today. . -2 temp today... new plugs and sled screams for 15-20 minutes then starts popping and then plugs foul... .



plugs are golden brown after wot run... ... ... how do you time a sled?

 

[MCharlebois]

btw... sled idles down to 500rpm at times and that is when i get alot of the fouling ,trying to get sled back up in rpms

marcel

sorry if post is kind of all over . . just trying to give as much info as possible

 

[Graphic man]

it could be a coil breaking down when it gets up to temp at WOT



i have a service manual somewhere around for the 583-670HO

 

[Graphic man]

i would also pull your carb slides and move the needle down 1 notch... it try that

 

[zstroken]

PUll the UFO's and try the stock jetting. I really think the backfiring is a ignition related issue. Bad coil, etc, etc.

 

[Graphic man]

PUll the UFO's and try the stock jetting. I really think the backfiring is a ignition related issue. Bad coil, etc, etc.

i agree with ya on the ignition issue.

 

[MCharlebois]

thanks guys,i will try the needle jet and i was planning on taking out the ufo`s to see if that was it. . the guy that worked on my sled has a 670 with ufo`s and said he fouls alot of plugs also... !! a definate improvement with them though

marcel

 

[PToombs]

What's a ufo? In a sled, for the wise apples!

 

[Turbo Tim 1]

I had an old 340 Arctic Cat that when it got warm it would spit and sputter and die, if you let it sit for a while it would start right back up. Ended up finding a hole in the back of one of the coils and when it would get warm it would start shooting sparks out against the engine.

 

[MCharlebois]

a ufo is a plastic piece on the bottom of the slide to help get more fuel and air in



tim,hows the 66... i bet she pulls hard top end

 

[Turbo Tim 1]

I'd kind of like to dyno it before I change anything, with the box off it sure feels like it hits harder, maybe on the dyno the headgasket will hold??? I haven't had the box on much at all since installing it, the 40 psi boost gauge spins around in about half a second so I've been taking it easy. So far so good I like it so far.

 

[MCharlebois]

so its a little scary huh :-laf you must be planning on headstuds befor pulling... i have been running with the box off mostly too ... man this cold weather makes um rattle i LITTLE with the box,... ... ... . i felt like i was going to break something with the smarty in the mix... bad time of year for me to be doing that!!!





UPDATE..... i let the sled idle and run for at least an hour last night... with the track in the air i could not get it to duplicate the problem,kids were sleeping. noooo need to **** off mama so no real world runs... no sparks from the coils ... . i believe i will wait on adjusting the carbs... my cousin, glen durfee said he would take a look. . anyone heard of him. . was fastest in the usa a few years ago /grass drags/ice drags... 01. srx . . tweaked a little :-laf

marcel

 

[CAT 385]

Are the pistons in the correct way w/ arrows pointing to the exhaust?

 

[MCharlebois]

i do not know about the pistons???i went for a 2 hour ride tonight... only popped a couple times on a long straitaway. . other than that ran great... the guy i was riding with ended up with a couple hundred feet on electric fence wire wound around his track. and shaft . . glad he was leading :-laf :-laf

marcel

 

[DValentine]

Is this an MXZ or what? I have a 98 Summit that was fouling plugs like crazy. I had a guy take the HAC off..... the High Altitude Compensator. Now the sled runs like a skinned cat. The guy jetted it off the Grand Touring of the same year.



Dave

 

[MCharlebois]

it is a formula z

marcel