[kaptiankent]

This sound has not always happened. It started last season near the end of the season and then now its back again. Went for the first ride last weekend and its getting louder. I thought it was the clutches so I bought a whole new primary and rebuilt and cleaned the secondary. I had the whole exhaust off, even the manifold and resealed everything. Had the chaincase cover off last year and everything looked good, still has clean oil. Checked the tension at that time to. All the skid bearings are good and I grease and oil all the other moving parts. The performance is unaffected so im stumped. What could it be? And it's getting louder.

 

[kaptiankent]

O ya I forgot to add that it only happens in between 40-60KPH all other times its gone.
Thanks in advance.

 

[mxzeatr]

Mine does it too, My clutches are fine, just seems to be a little noise at certain speeds. I have heard that it could be belt slippage.

 

[mrtolkien]

I have a 01 Formula Deluxe 600 and I think I kinda have the same things. I catogorize it more like a bird chirping... Kinda hard to explain how it sounds using words. ... lol

Anyway, my sled also seems unafected by what ever is causing the noise. My belt is fine and it also only happens at about 40 to 60kms. Could still be their above 60 but I guess all the other noise drowns it out.

 

[700GSE]

Phasing? When the motor speed phases in and out with the track speed (read sprockets)... I've noticed it too... When you're running at low speeds, the "whirrrrrring" sounds intenifies around 40kph, and goes away after 60.. In my opinion, it's the motor vibrations phasing in and out with the sprockets on the track - no worries. I would think replacing the sprockets would get rid of the sound.

 

[kaptiankent]

I thought it might be belt slippage but never thought it would be the track an sprokets. I was just concerned because it only started doing this at the end of last season. I did put on a few thousand k's too.

 

[APC]

Check the brake disc. Is it running close to the tunnel? If your brake pads wear down the disc floats toward the tunnel sometimes.

 

[kaptiankent]

Well I got back from another weekend of riding and the noise is worse. It now sounds like theres a whistle somewhere on it. I find it only happens after its warmed up after like 5-6min of driving. It seems to be happening between 20k to over 100kph. The tone changes depending on how fast you drive. Its like a hight pitched whistle, sometimes so loud it is ear pearcing. Seems to be a lot worse since last season. I don't think it's the track sound because I can hear that to and I can also hear the brake sound to, This whistling sound is totally different. Its driving me nuts and I dont know what to do........

Any more help would be great.
Thanks guys

 

[Mallett]

Did you change your belt lately. I just install a ultimax 3 and mine started to give the same symptoms as you. Hope this is a common factor or my problem is not answered either. Let me know please.

 

[kaptiankent]

I put an ultimax 3 belt on halfway through last season. Mabe it is the belt? I don't have a bombardier belt to try though. Seems to make sense since it started around the same time. I am going away again this weekend and will try putting on a new ultimax 3 belt to see if it helps.

 

[01800SummitHighmarkX]

look at your carb boots, i had same problem and had cracks in them and got new boots and it was gone. BIG $$$ tho because they are attached to the reads. unless its different on a summit which it shouldnt be, just throwin in my .02
charles

 

[kaptiankent]

Well this weekend I had the sled out and went nowhere. It was running way to lean. The one plug looked ok and the mag side was white. Thought it was carbs-there clean, thought it was the DPM- tried unpluging it to run it full rich and there is no difference when its on or off, still to lean. Check the carb boots and reed valves- they look great. What else is it? I think the fuel pump or the mpem module is the last things to check.