Scraping noise

[MarylandMagnav45]

Hey Guys:  One more question.

When riding my magna, as I'm raising the revs, I sometimes hear this scraping noise (I think).  Its mostly heard in the first 3 gears...

It doesn't make a sound if i keep a constant speed nor in the higher gears.

Even if i'm going 30 mph and i'm in 6th gear, I don't hear it if I increase speed to 50mph etc...

Its not the "wind", and my bike runs great.  I've used a heavy dose of Seafoam recently.

My engine oil is good.

Any ideas?

[MarylandMagnav45]

bump

[Chad in Michigan]

maybe your chain?? i think mine did that when it started to get dry.

[hootmon]

maybe your chain?? i think mine did that when it started to get dry.

Dan has a shaft drive... 

[Chad in Michigan]

well i guess it's not a chain, lol

[hootmon]

well i guess it's not a chain, lol

It could be a cam chain.. on Dan's bike..

Did your cam chain ever get dry Chad?? 

[Chad in Michigan]

boy i hope not, lol 

[Justin]

When the cam chain tensioners went on my 3rd gen it was making a slapping/thrashing/grinding noise sort of like a bent push rod or broken lifter in a small block. The noise was intermittent when only one tensioner was broken, by chageing to a semi-synthetic oil it eliminated the noise  completely. When the second tensioner went the noise was non stop, but there was no loss in performance just terrible terrible noises coming from the engine.

[hootmon]

When the second tensioner went the noise was non stop, but there was no loss in performance just terrible terrible noises coming from the engine.

An Aluminum fragments in the oil pan?? 

[Justin]

Nope it was just the sound of the timing chain slapping the inside of the case/head i checked a few times for metal fragments or debris(soot, Carbon, gasket) in the oil and nothing, I can't even see evident wear on the chain, keep in mind i only put on like 10 miles maybe with them both broken, and i think one of the tensioners was broken since i bought the bike.

When i replaced them the rear tensioner(the one under the seat) was fubar'd it fell apart into 6 or 7 pieces upon removal, the front tensioner (the one in the V of the engine) was just seized at about 3/4 position and i was unable to pull it apart to inspect the spring and screw shaft in it without just smashing it to pieces with a sledge.

But like i said other than it sounding horrible, I had no performance loss. At the time when the second tensioner broke i was Light racing a guy on a Indian, I had beat him on the other two lights and i wasn't about to lose on the 3rd light so i just raced him anyways then limped it home.