Howling at idle - uh oh

[steveg_nh]

Scroll down to where it says V-belt height. The spec for belt height is .5 mm below the top edge of pulley to 1.5 mm above it.

https://totallyamaha.com/snowmobiles/aaTECH/drivespecs/secondarysprings.htm

I am about 1mm above so within spec.

 

[musselman]

I like the belt on the tight side (close to 1 mm above) so you are probably ok just ride it and see if it keeps making the noise, if it does then remove a spacer to lower the belt closer to flush. All belts vary in length slightly so you might just have a belt that's on the smaller side.

 

[steveg_nh]

Thanks. And I would imagine, if the issue was an IAC hose, I would hear noises all the time, not just after running it around the woods and back...I didn't even check last night. I might use my inspection camera vs pulling the pod off.

 

[Elton Buss]

The one problem you will have with a tight belt is the sled will not go into and out of reverse easily. The clutch will keep to much pressure on the belt.

 

[steveg_nh]

Thanks. Maybe I should just drop it a bit to even with top of clutch. I did notice getting out of reverse felt a bit stiff the other day!

 

[thor452]

run it on the trail and if it starts making noise again adjust it. you have a new belt and new buttons in the secondary so I would expect it to be tight and need a little run time. If it don't go away in the first 100 miles it should be adjusted easy to do anywhere so let it break in first is my advise.

 

[steveg_nh]

I like that advice! Lol

 

[STAIN]

I have found the Yamaha's like the belt a little lower in the secondary than other brands. I used to run my Cats a little above the sheaves but on my Yamaha's they make belt noises when set up like this. I run them flush .

 

[steveg_nh]

Good deal, Steve!

Remember, if you decide to lower the belt in the pulley, you have to remove washer(s) from each of the screws.

Yup!

 

[steveg_nh]

Got this taken care of today. Removed a .5mm shim from each adjustment screw. It dropped the belt just below the top of the secondary but the howl is gone!

 

[CaptCaper]

Thanks. I just fixed the broken link to the video above too. So that must be it then, the belt, as I didn't hear it until after I did the run aroud the yard.

So if the belt is a bit tight, but it's sitting correctly in the secondary, what should I do? Let the belt break in a bit before messing with anything, or adjust the clutch so the belt is flush, vs above 1mm?

I think it would take an aweful long time to break in... best to remove the shims. You reverse will love it too.

 

[steveg_nh]

Productive day in the stable of sleds.