Burgman 650 K4 - rough transmission?

[Francley40]

2004 Suzuki Burgman 650 - only 7000 miles done.
In good shape. Owned by me for the last 3 years. Doing a massive 8-900 miles a year

I was out on the Burgman today and noticed a possible issue.
I'm not sure if its a new issue or has been there all along and I never took notice before...

When accelerating the scoot is nice and smooth but when I get to 3000rpm the bike feels slightly rough for about the next 250-350rpm and then everything smooths out again.

It doesn't feel like an engine problem, more a transmission problem.

Don't know what I'm talking about, here, but I'm thinking maybe the sliders need a clean up?

Any helpful suggestions gratefully received, thanks.

[victor]

when was the last time tyres were changed, did you have the bearing done.

[Data]

First thought is that you may have lost a wheel balance weight, probably from the rear wheel. But could be a CVT issue as you say, but I would say that's unlikely. Check both tyres and make sure there is nothing stuck in them. Is the oil in the tranny ok and up to the full mark?

[kayz1]

No rollers or sliders in the 650..
Lyn.

[Data]

The only issue I've come across that sometimes causes vibes is a sticky ecvt servo unit or a slow to lock up clutch on the 650. These can cause vibration similar to what you describe. I've rebuilt the trannies on a couple of these bikes where the bearings and belts had gone south, but I doubt it's a sign of anything so big starting to go wrong. However there are some known weaknesses in the early bikes so I'd keep an eye on it for the time being and note if it is getting worse or not. I'm sure you are aware of the stopper bolt issue too. But check the oil level, that's important, very important.

[Francley40]

Many thanks for the suggestions.
I'll check them out at the weekend and see what comes to light.
Regards,
Chris.

[Francley40]

I finally made some time to check over the scoot and this is what I found.
I bought a new stopper bolt but when I took the 'old' one out it was in very good condition and was same length as the new one, so had been replaced along the way somewhere with the updated part. Anyway, I put the new one in as I'd got it...
I'd done an oil change recently and the level was bang in the middle of the upper and lower marks. Taking note of Data's advice I put another 100cc of oil in which brings the level up to a couple of mm's below the upper mark.
Went for a spin and the roughness has all but disappeared - you can just detect it, now, but it feels totally normal and nothing to worry about. Think I'll squeeze another 50cc's in so as to hit the upper mark.
Also, I did a bit of research on the BUSA site and these vibes seem to be a common occurrence and 'nothing to worry about' according to our American cousins.
Thanks for your help, Muppets.

[Data]

Yeah...that's about right! Keep the oil level at the full mark. It does seem to help reduce the vibes and makes the tranny run cooler. These vibes are not unknown on the earlier models so don't worry unless you notice it getting very bad. I've not ridden an earlier one that doesn't vibe a bit.