Hello guys,

I am new here, just got my little bike a week ago. Got her pretty cheap, 1990 with 22000km on it, but in pretty bad shape. The fuel tank had a rust hole in it which I had to weld, and repaint. I also had to balance the carbs as the idle was unpredictable and rpms would come down really slowly.

Now that all these problems are solved, I have another one I can't figure out. There is grinding noise coming from chain area when bike coasts, but once I give some throtle, the noise goes away. When the grinding noise is present I can feel the vibration in the footpegs. I think it is the chain dragging on the swingarm, but I am not sure. The chain touches the swingarm when the bike is on the stand, but it also does when my wife sits on it. This should not be happening, right? What would cause this and any ideas how to fix it?

Thanks in advance, for your help.

Doug.

Here is the picture, if you are interested to see what she looks like.

Sounds like the chain needs adjusting. Worst case, depending on age/wear, the sprockets and chain may need replacing.

and....welcome to the GS.   

Quote from: dgyver on August 23, 2006, 12:53:19 PM
Sounds like the chain needs adjusting. Worst case, depending on age/wear, the sprockets and chain may need replacing.

and....welcome to the GS.   

Ah, the chain is brand new, just put it on and it's properly adjusted. This thing is driving me nuts, I am worried the chain will eat through the padding on the swingarm and start rubbiing on the metal.

Cheers,

Doug.

What size is the front sprocket?

I'll have to check when I get home, it wold not be cool to start taking my bike apart in the office parking lot . I will post the size tonight. What should be the size of the stock sprocket?

Cheers,
Doug.

Stock is 16T. Many will drop down to 15T. A few will use a 14T. The 14T will pull the chain tighter to the swingarm.

Also....the stock rear is 39T

Grinding noise is also typical for an overtight chain. But that would not go away under load.

On the sidestand the chain should have 20 to 30 mm slack (you should be able to lift it 20 to 30mm.)

The front sprocket is 16T and both front and rear are in really good shape. I think the real wheel might have been out of alignment a bit, so I just fixed that and tighten the chain a bit. Will have to take it out tonight (have to take daughter to soccer first) and see if that helped. I also noticed that the handle bars are shaking side to side on the way home from work, as if the bike is about to go into tank slapper. What would cause that?

Did I buy a lemon?

Thanks for your help guys,

Doug.

if you did't align the rear whell right when you adjusted the chain that could cause the rear wheel to be out of alignment.  Check the swingarm, there are marks on it so that you can adjust the chain and keep the rear axle straight.  It is possible that the axle nut wasn't tightened enough and this pulled the axel out of alignment.  Anyone have a pic of their swingarm?

As far as the head shake, deffinately check tire pressure in the front.  Also make sure your front brake isn't dragging.

As far as your bike goes...I friggin dig the silver with no graphics.  Very clean and super bitchin'.

-Turd.

Thanks for the kind comments, it was my wife's idea to paint it silver. Well it was more of an ultimatum, the bike is going to be silver or it's not going to be .

I think the head shake problem must be wheel balance, as it does not happen at all speeds and there is a brand new tire on it. As far as grinding noise, tightening the chain didn't fix it. I checked the front srpocket last night and everything seems to be fine. Begingin to wonder if something is out of alignment, maybe the swingarm since the bike's been dropped according to the scratches on the left had side.

I guess I'll have to take it to the mechanic and see what they think.

Cheers,

Doug.

Can you make photos how the chain runs over the swingarm / centerstand / into the sprocket cover?

It has to be a bad wreck that twists your swingarm.

I will try to take some pictures tonight when I get home, but on visual inspection everything seems okay. Thanks a lot for trying to help.

Cheers,

Doug.

Just read the rear wheel alignnment thread, ran out of my office with the ruler and did some measuring. The rear wheel is grossly out of alignment and after I checked the rear sprocket, it appears that the outside is all nice and shiny (ground) while the inside is pretty greasy. The funny thing is the marks on both sides of chanin tensioner are at exactly the same position. I guess I'll have to align the wheel using measurement rather than swingarm markings.

I hope this solves my problem, had trouble sleeping last couple of days. Will let you guys know how it works out today after work.

Cheers,

Doug.

Hey guys,

It appears the problems are bigger than I thought. Took off the front sprocket last night and realized that it had a lot of free play. I guess someone ran the bike with the wheel out of alignment which made the chain run crooked which put a strain on the front sprocket which damaged the drive shaft...which means the engine has to come out, have to split the cases and replace the drive shaft.

Ah, so much for riding for the rest of the summer. Thanks for your help trying to figure this out.

Cheers,

Doug.