Funny noise from my 00 MM (video included)

milo303

milo303

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Funny noise from my 00 MM (video included) (update)

Took my MM out for the first time ever as me being the owner, today.

Started right up like normal down in Denver, got it on the trailer, went up to vail pass. Started right up and was idling like normal than it started with this weird squeal noise, and decided to die on me. Then it didn't want to idle right the rest of the day but ran fine otherwise.

The sound seems to be coming from the clutches but in person it was very hard to pin point for some reason. The video actually captures it better than I could hear it in person.

Side note I installed 10" risers and I had a mechanic run my carbs and install/adjust the throttle and oil cable. I'll figure out how to set the idle a fuzz higher but I just wanted to toss that out as to make sure oil wasn't an issue. It was using oil at a fairly good rate, about a quarter of the reservoir to a quarter to half a tank of gas, approx.

But anyways heres the short video. I wanted to make sure I got the squeak and what it sounded like being revved a little to get a couple variables of sounds.

Thanks guys

http://s231.photobucket.com/albums/ee150/Miloinkc/?action=view&current=slednoise12132011.mp4
 
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Sounds like belt squeal - but it is hard to tell from a video. I does sound like it is missing part of the time too.

Check your plugs, and post pics if you can.
 
I should replace all of the plugs anyways and the belt is brand brand new so it could be belt squeal...

Now that you mention that it wasn't making that sound with the old belt on it.

And how the heck can you tell it's missing?? Your ear is way better than mine
 
Sounds like belt squeal to me too, it went away when you revved the motor up some. There are three bolts on the back side of the secondary, they are either wore and need replaced, or you can remove the washers from them if they are there and put the bolts back in to stop the squeal. Common when a new belt is put on. The bolts are for setting belt deflection, add washers and the sheaves sit closer together, remove them and they are farther apart. If the belt is riding too high in the secondary, it pulls it tighter on the primary and it'll squeal at an idle.
 
check in the tech section about setting belt deflection. I have a new to me 02 mm and the dealer had put a new belt on it. It squeals like a little pig at idle. From what I've read it should go away within 100 miles once it's broken in. I've got a ultimax xs to put on it for this winter when the snow shows up, the word on the street seems to be that the yamaha belt it hard as a rock, it will last forever but slips a lot because of that. It's going to be my backup belt now. As far as setting your idle it's easy. With the motor warm the idle is easily adjusted by turning that screw with the springs on it right next to the TORS harness. If you turn it clockwise it will increase your idle, I turned mine a little bit less than 1/4 turn to bring my idle up from +/- 1000 to +/-1600. The belt squeal actually went away with the higher idle too. It's not too hard to adjust the cable afterwards too. Loosen the lock nut on the throttle adjuster, turn it counter clockwise to take up the slack, you want enough slack in the cable so the TORS toggles on the thumb throttle and then pulls just a bit of cable before the carbs start to open. If you hold the throttle to the bar, try and move the carb cable cam. If it can't turn any more you have all the slack out of the cable. The oil adjuster is easy, slide back the 2 rubber boots, pull the cable housing out of the adjuster, it should be 22mm from the cable housing end to the end of the adjuster.

What's been done to that sled? What brand of head and pipes are on it? If you get too erratic an idle you might want to get your crankcase seals checked. I lost the motor in my modded 86 polaris last winter. If was idling funny, had intermittent hard starting and the motor would hang at around 3000 rpm before settling back down to idle. The pto crankcase seal was shot, that jug ran lean and wiped out the piston. It was an old 600 punched out to a 720, we couldn't find a single piston to replace it and the sled wasn't worth a new big bore kit. She's in the junkyard now, and I have a sweet MM700 to ride instead.

If you need a manual, I have the pdf of the factory manual and well as the service manual on pdf I can email to you.
 
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If you want to get rid of the squeal with a new belt, there are three phillips head screws on the back of your secondary clutch. They will have washers as spacers to bring the sheaves closer together. For a new belt take all washers off and replace screws. This should eliminate the squeal. Keep those washers for down the road when the belt wears.
 
Sounds like the actual clutch. Sounds like my old ski doo clutches when they need to be cleaned. I don't think the sound really goes away when you rev the motor. Doesn't seem as pronounced as belt squeal. How about pulling the belt guard off? may be able to hear it better. Not the safest thing to do but it may give us a better idea. Can you get a video of the other side of the motor with it running too.
 
Hey you guys are a ton of help!

I'll start with what Backwoods explains and go from there.

The previous owner bought it new, he had 6 of them total for the whole family. He slowly sold them all off and updated his fleet, and his personal was the last one. I picked it up for $1600 and it is very clean..... I consider myself rather lucky. Rolled chaincase, brand new track that never saw snow till yesterday, elkoln tunnel, bender pipes, but that's all he claimed was done to it.

BUT it has the Mountain Performance high performance head on it, and flippin screams..... He made no claims to any motor work whatsoever but at minimum it's got the head on it. The mechanic I took it to specializes in Mountain Max's and he went thru it for me and at first he was a little hesitant because it has a couple miles on it, but when he was done looking it over he said I stole the sled and there's absolutely nothing to worry about with it.

So who knows if it has a big bore, just the head, or what.... I just know it screams... Faster than my built banshee I had in high school for sure.

But anyways, I'll tinker with it and give you guys an update. I'll have some helmet cam footage before long also. Just need some real snow out here and some more skills.

I got a lot of respect for you guys who can make these things dance. It's nothing like the atv's I grew up on and you really gotta have your balance and weight distribution down on these sleds.
 
It does sound like you have a low end miss/stumble, might need to clean the pilot jets. This would be the reason for low idle and dying.
 
I would definately clean the carbs. It sounds like a pilot is plugged that's why you're losing a cylinder on idle. Probably had a chunk of crap get loose from the tank and plug them pilots up. The belt squeal can be fixed like these other guys have said.
 
sleddineinar said:
I would definately clean the carbs. It sounds like a pilot is plugged that's why you're losing a cylinder on idle. Probably had a chunk of crap get loose from the tank and plug them pilots up. The belt squeal can be fixed like these other guys have said.
Click to expand...

2x that sounds about right.
 
The mechanic I used cleaned the carbs before this time out. I used some am soil ethanol eliminator, could that have anything to do with it? I'll change the plugs but I hope he didn't screw me on the carbs
 
sleddineinar said:
I would definately clean the carbs. It sounds like a pilot is plugged that's why you're losing a cylinder on idle. Probably had a chunk of crap get loose from the tank and plug them pilots up. The belt squeal can be fixed like these other guys have said.
Click to expand...

I also agree!

when you rev it up it sounds like it's only running on two cylinders, it stumbles some, with those pipes that thing should sing as soon as you hit the throttle. Your mechanic is who? he/you need to clean the pilot jets again, that should solve your problem. You might as well do it yourself because it's something you will have to do every year prior to your first ride. Check the tech section, tells you everything, that way you know its done right.
 
x3 on the carb cleaning, sorry I forgot to mention that. It might not be a bad idea to do a compression test once a year (start or end) at the same time and write it down in the manual or whatever you have to keep track of the motor's health as time goes on. Let me know if you want those pdf manuals
 
Take the belt off and start the sled and rev it up just a little bit to see if the squeal is there with the belt off.
 
Racing666 has a great plan. Just don't get too carried away with the rpms. There is definitely a problem on the low end fuel circuit. Sorry, but that sounds unhealthy. It should be way more crisp than that.
 
I wouldn't be surprised if they unbolted your motor mounts to better put your oil cable on and messed up your clutch alignment just enough to squeal. Do what another posted, take the belt off and see how it runs.
 
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