How do you know when your crank is bad?

[theo547]

earlier this week my Scooter started making this NASTY sound coming from what i think is the crank area... ive reattached my exhaust, taken off my e-starter gears (though this seemed to make it better).

The main thing im noticing right now is that it sounds much louder and from 1000 to almost 2500 rpm it sounds like the engine is really struggling maybe even hanging up somewhere.. beyond that point it sounds pretty normal... any ideas?!

[dude]

Most of the time if its a crank bearing that goes bad its the one on the CVT side. You may grab the var. and move it up and down. look for oil leaks around the bearing seals.

(taken off my e-starter gears)??

It maybe something in your CVT.

[theo547]

there is oil around the seal behind the variator... so i think taht seal is for sure leaking... could that leak be causing the sound?? the sound seriously had me thinking my exhaust was leaking at first.

[reveeen]

Look for abnormal heating in the case/bearing area.

It should shake a bit like a dog trying to crap razor blades.

[jmkjr72]

when you see joel and yvonne ask them how i found out i had a bad crank

but yeah check for play on both sides and on the rod

[theo547]

well im happy to report that im a moron and my scooter is pretty much OK - the "exhaust" sound i was hearing was coming from my air box.
the area where it attaches to the carb had a few fairly large cracks that were leaking air... atleast i pray to god that thats the sound i was hearing, because if its anything else its in the engine itself... took everything apart today and thats the only thing i found.

anyways thanks everyone for your help.

[one1]

My starter clutch was making terrible noises when it started going out, but i don't know what you're hearing.