Funny vibration/rattle @ 6k

[evilimprdr]

So I got this vibration/rattle noise at 6k. It stays there until you get to 7k and then it runs smooth as silk both before and after. I thought it was my chain so I adjusted it tonight(first time with a bike many a quads). Took it up the road and I could tell that didn't fix my problem. Or is this not really a problem and it's just the way this engine is? Any tips?

Also on a side note if my "notches" on the swing arm are about 3/4-1 notch off. Is this cool? I couldn't get the damn things to line up even.

[ryott52]

The notches aren't too reliable, the little washer things with the notches on them tend to shift a bit. It's better to measure or count threads protruding from the adjuster nut. How old's your chain? And did you check the tension at the tightest point while sitting on the bike?

[crzydood17]

notches aren't accurate, use one of the methods to properly align the rear wheel and then use the turn count method to tighten the wheel...

String is a cheap one and you just need string, measuring device, 2 heavy objects.

http://www.yamahafz1oa.com/sportryderswheelalignmentmethod.shtml

[mister]

How are Both of your sprockets?
Are there any tight spots on your chain?

Both can create Noise at certain speeds in certain gears.

Michael

[ben2go]

So I got this vibration/rattle noise at 6k. It stays there until you get to 7k and then it runs smooth as silk both before and after. I thought it was my chain so I adjusted it tonight(first time with a bike many a quads). Took it up the road and I could tell that didn't fix my problem. Or is this not really a problem and it's just the way this engine is? Any tips?

Also on a side note if my "notches" on the swing arm are about 3/4-1 notch off. Is this cool? I couldn't get the damn things to line up even.

Has the bike been dropped and is the noise coming from under the fuel tank?I bought my 89 with a rattling buzzing noise and it was from the PO dropping the bike.It bent the tank mounting bracket just enough to let the tank buzz against the top edge of the frame.It appeared to have plenty of room to move but it didn't.The tank gap should be between 1/8th and 3/16th of an inch.Add a couple fender washers between the tank and mounting bushing will raise it enough to stop buzzing.Another thing to check is the tail plastics rubbing the lower edge of the tank.They can be adjusted by loosening the bolts and pushing them around while tightening the bolts.I agree 100% to not trust the alignment marks on the swing arm.I measure mine from the center of the pivot bolt to the center of the axle bolt.If the swing arm or frame is out of square,you'll need the string or laser method to align the rear wheel.Do a search and the threads will come up.

[evilimprdr]

Bikes brand new and never been dropped. Has 2k on it and it's just now showing just under 1.5 of slack on the chain. I check it regularly and the other day was the first time I have seen it out of whack. I haven't rode the bike since. It's been doing it for about a 1k. Of course if I really think about it it has done it more than not.

[Twisted]

What I find with the GS is it's vibes have a habit of making bolts magically unscrew and disappear. See if you can find any bolts missing from anywhere.

Loctite is your friend with a GS.

[ben2go]

What I find with the GS is it's vibes have a habit of making bolts magically unscrew and disappear. See if you can find any bolts missing from anywhere.

Loctite is your friend with a GS.

You hit that one on the head.I use just a small drop of blue loctite on all my bolts and nuts.If it is a critical part that only gets removed when it breaks down,then I use red loctite.

[DaielHancock]

on my previous bikes i have had big vibrational issues, first one was due to the engine mouting bolts being loose! so check all torques on them.  Also my baffles came loose on my old suzuki en125 which causes insane vibrations between 5k and 6k, might be that?

[evilimprdr]

Well I think I figured it out. I took the plastic off and checked the bolts. All were tight. Nothing out of the ordernary. After that I went for a quick ride around the block in second gear which is about 6k for me. It seemed worse and/or more pronounced with the plastic off. It sound like it was coming from right in front of me. So I started to put pressure on the plastic in the cockpit area. I got quiter and less vib in the bars. Seems I have some loose plastic around the headlight or something. Didn't really feel like digging into it tonight. Tomorrow's fathers day and if it's nice my present from my kids and wife is to get away and ride. So in the morning I'll put the plastic back on and go for a ride. Chain is good to go and I'm happy with the alignment for now. So all is good in my GS world for now.