noise from rear end By jenningsjosh (Read 6,052 times)

[jenningsjosh]

I have started to notice a ratteling noise coming from the rear of my cvt or back tire... I only hear it when I am on the road and accelerating... not on stand and not when cruising without gas... like downhill nothing... but if I hit the gas at all.. it rattles.. I don't think it is my exhaust or I think it would do it reving on the stand... the noise is progressively becone louder and louder... slowly but I can for sure tell...

Thoughts... suggestions?

[kz1000st]

So last week I'm riding to the Bike Night and I start to hear a rattle from the back. "Darn single cylinder engines, it's got an exhaust rattle." The next day I get down on my hands and knees and look. Sure enough, the rear upper exhaust mount bolt is gone. I take a new one and a washer out of stock and replace it. Out of curiosity I get my 8mm socket out and check the muffler heat shield bolts. Yup, one is loose. Noise is now gone. My 150cc scooter needs exhaust bolt checking once in a while too.

You did put oil in the gearbox when you replaced the shaft I presume? Also check your shock bolts. They are stretched when on the centerstand which puts tension on them.

[jenningsjosh]

Yeah I put in gear oil.. I don't think its shocks because only happens when I give it gas. And I checked over the exhaust.. but I guess I need to recheck with socket...

[bhinch]

You might want to check the rear axle nut. I have to retighten mine on a regular basis. When it on the center stand, I check the side to side movement on the rear wheel. I use blue thread lock on the nut. Just a thought....

[jenningsjosh]

Ty! Everything external checks out.. I mean a few bolts were slightly lose but did not help rattle at all.. I have a feeling its something to do with the shaft I put it... I will check it sometime soon.. any other suggestions are helpful thanks

[jenningsjosh]

No other opinions on what the sound may be?

[taildrag]

Yep..had the same rattle on my Roketa MC 54B 250. Turned out to be the chrome thingie that sits on the side of the muffler. Tighten two bolds...rattle gone.

[jenningsjosh]

That thingie is called a heat shield... and yes it was checked..

Ok.. now I am worried.. I am starting to "slip" on take off.. and I have to give it a lot more gas to takeoff... comeon pros.. I know you can help me out here

[kz1000st]

Check that the bell housing on your clutch on that shaft you just installed isn't coming loose. I tightened mine to 70 lb. ft. and used loctite on it. That would account for your clutch slip and noise.

[jenningsjosh]

Ok.. I have been dreading gettin into the cvt again... but guess this weekend I will check er out.. maybe drain my gear oil since break in of new clutch is done.. and refill... shoot maybe it has a leak and I don't have any fluid in there... I will check...

Thanks agn.. any other opinions are always welcomed and thanked

[jenningsjosh]

Mother flipper!!!! Rahhhh.. so I had an hour before school started.. I thought.. well I have time to check fluids and check nut on bell housing...

Got cvt cover off.. and got out impact wrench... took off varriator... and then I tried to remove clutch nut.. and BAM the flippin shaft broke AGAIN! the fluid level was fine.. so i still dont know what the noise was from! But now i need another new shaft

Blahhh my faith in chinese scoots is dwindeling.. I love em.. and I hate em!

[jenningsjosh]

I ordered another from pfs... damnit! Well now I get the chance to look inside and see if that was where my rattle was coming from... maybe I installed it a little wrong and it was wearing down the teeth? I dunno but will have to wait a a few days to find out.. just what I needed

While I am in there.. can anyone tell me where I can get the taller gears for the cf moto 250?

[bhinch]

Sorry about your shaft problem. I had the center stand rubber wheel rubbing on the bottom of the engine. When I would accelerate it would sound like a rod knocking and really loud. Took a rag and placed under the center stand when it was up and the rattle went away. I ordered a new rubber bumper wheel from Roketa and replaced it. Just a thought...

[jenningsjosh]

Thanks.. that's not causing my sound either.. my center stand does not touch anything but the frame..

I took apart the shaft area this afternoon and all looks well on the inside.. had plenty of new grease and everything still looks like new inside..
I did notice that the exhaust clamp was a little loose so I tightened it down.. there is like a metallic type of gasket that goes under the clamp.. I cany recall noticing it before... so I loosened it up first.. tucked the gasket like material back down and retightened. I won't be able to test it tell I get the new shaft come monday or tuesday.

I think maybe where my rollere are flat might has had something to do with rattle? Does that sound right? They are just small flat spots...
One more quick thing.. the sound gets louder as it gets warmer.. when I have been on road for more than 20 mins.. its very very loud. When I first start off.. I can hear it just barely under the sound of the engine.. but when warm.. it is louder than engine
Anything else while I am down would be appriciated

[kz1000st]

I'd replace the shaft and see if the noise is still there. It's possible that the sound and a shaft problem are related.

My advice is to get a strap wrench to hold the bell housing and use a torque wrench to tighten the clutch nut if you didn't the first time.