Black flakes falling from bike

[woodthumb]

ok heres a new one and a real stumper for me... back from long ride 2 weeks ago and last 150 miles was in heavy rain... so, after bike sittin in garage not running since, i started it today and when throttling up while on stand, little black specks spew out of bottom of bike around area where belt goes into main drive.. the more gas i give motor, the faster and more they fall out... i'm talkin alot of specks... looks like small carbon flakes as it stains hands when smearing...weird.. could it be belt wear that was caked up in there from all the rain ? normal you think ? belts not moving of course at idle so whats the deal here ? 6300 miles on bike .. thanks all

[recumbentbob]

Take the cover off and see

[smokey]

throttling up on the stand with the transmission engaged? sounds to me like you are blowing carbon out of the muffler area where it connects into the exhaust header on the left side, if it was the belt it would be like small bits of rubber. If the gears are not engaged then you would get more as you are pushing more exhaust out so more pressure.

[ringadingh]

It could also be caked on belt dust that got loosened while riding through the rain.

[cnc]

Gonna agree with Steve on this as a possible cause. Snowmobiles have belt drive and there is always a fine black dust caked on the belt guard and the drive side of the motor from normal wear.

[woodthumb]

Originally Posted by cnc

Gonna agree with Steve on this as a possible cause. Snowmobiles have belt drive and there is always a fine black dust caked on the belt guard and the drive side of the motor from normal wear.

appreciate all the input but this is not fine dust..it is like course ground black pepper and will smear in your hands like charcoal when you rub it... dealer has bike now to check my cruise control problem and is also stumped.. i took him a sandwich bag full of the stuff i swept off the garage floor..i;ll let you guys know when we know.. i just cant get under the bike good enough to see but appears to be dumping out directly under the exhaust cross pipe in a very tight pattern... like its coming out of a small hole

[skullbagger]

Originally Posted by woodthumb

appreciate all the input but this is not fine dust..it is like course ground black pepper and will smear in your hands like charcoal when you rub it... dealer has bike now to check my cruise control problem and is also stumped.. i took him a sandwich bag full of the stuff i swept off the garage floor..i;ll let you guys know when we know.. i just cant get under the bike good enough to see but appears to be dumping out directly under the exhaust cross pipe in a very tight pattern... like its coming out of a small hole

its a lil hard to guess at it with out seeing it but I would check your tire, maybe your overloading the bike and bottoming out the tire on a fender nut or something of that nature, but then again it sounds like a carbon build up if you can smear it. does the back of the bike have black hazey dirt like build up on it maybe above your exhaust, take a long brush and go inside your tail pipe and see if you can bring out the same product so to speak and compare

[redjay]

Originally Posted by smokey

throttling up on the stand with the transmission engaged? sounds to me like you are blowing carbon out of the muffler area where it connects into the exhaust header on the left side, if it was the belt it would be like small bits of rubber. If the gears are not engaged then you would get more as you are pushing more exhaust out so more pressure.

I think Smokey is on the right track.

[recumbentbob]

Well what was it?