Have I got a problem??

[drapes]

'98 storm..luv it to bits ...but..
This year I did a 2000 mile round trip to South of France. Before I went I obviously had the bike checked over.Replaced the carbon can straight throughs with original system and off to the workshop. Now this bike has run sooo smooothly all the time I've had it (years) but when it came back it felt, well, sorta lumpy and a bit down on power. almost as if I needed to change down all of the time regardless of speed/gear/revs! The prob appeared to affect the rear cylinder only.
Took it back and a slight adjustment was made to the carbs...but still the same symptoms. Any way it did the trip and didn't get any worse..but it didn't get any better either!
On my return, back to the workshop..they checked it over and decided that the problem was down to s**t and rubbish having been disturbed in the tank the first time.
Bike still runs o.k. but not as well as it used to..you know your own bike don't you.
So,if you've stuck with me so far..any ideas as to what the problem might be?
It ran fine on the original zorsts and fine with no adjustments on the straight throos. I just don't know what to think and being a bit strapped at the mo I can't just keep throwing dosh at it. HELP!

[sirch345]

You don't say which service the bike had, had at the workshop, so therefore I don't know what things were carried out

Did you have the cam chain tensioners removed/replaced

Also have you looked to see if the vacuum pipe is fitted in the center of the petrol tap diaphragm cover (at the back of the tap), and not to the drain outlet at the bottom

Chris.

[drapes]

Hi Chris...thanks for your reply.
It wasn't a really a service, I just had the bike checked over for my trip and the carbs were balanced. CCT's haven't been changed.

I've checked the vacuum pipe and all seems well.

To expand on the problem, for the first time ever on this bike I'm getting vibes through the pegs and bars..so much so that my watch had stopped working by the end of the trip and it started again within a few hours of my return. Vibes are better now but still there.

It's difficult to explain, but the bike is just 'thrummy'!...I'm beginning to get a bit paranoid about it, it's running okish but just ain't right.

[Fireman on a Storm]

Replaced the carbon can straight throughs with original system and off to the workshop.

Are you sure your not noticing the difference between the easier breathing race cans and the restrictive standard cans.
If the bike was Dino jetted for the race cans it may be struggling now the standard cans are back on.

I'm not a mechanic but I notice the difference in performance on my first storm when I put the race cans on (no re jetting). When it was written off and I got my new storm it felt a bit sluggish at first(standard cans). After about 6 weeks I put my race cans on it and noticed an improved pick up straight away.

Paul

[lee67]

vibes can be caused by inaccurate carb balancing....who did em?

[Wildfire]

My money would be on the Carbs...either balance or the fact the standard cans are on

[LotusSevenMan]

My money would be on the Carbs...either balance or the fact the standard cans are on

Or the combination of the two!

Depends where they balanced the carbs rev wise too. They aren't linear as in they can be out at tickover/ up to 1900 or so but then get 'in-line' and stay there. I balance mine from 2000rpm + on as that is where it gets used when riding. Mine is pretty linear from 1900 onwards. Does make a difference if it's only been balanced at tickover speeds as at the higher rpm it then goes 'out'.

[derryUK]

I always thought carb-balancing was to smooth tick-over out, when a small difference between throttle position could make a difference.

Remember that stationary you may be doing 2000 rpm but you won't have any load on the engine. You will need the throttles open more to do 2000 rpm when riding, there is relatively so much air flowing through the carbs that a small difference in throttle position will count for nowt.

Interesting idea though.

Derry.

[solorider]

I always thought carb-balancing was to smooth tick-over out, when a small difference between throttle position could make a difference.
Derry.

the reason to balance carbs is to equalise the airflow through the carbs,out of balabce carbs can affect any imbalance at high revs more so than low revs,i had a cbx550 a few years ago which rattled a lot,i changed the cam chain and no difference,i balanced the carbs and the rattle disapeared,the rattle was at worse at3000rpm than at tickover

[sirch345]

Hi Chris...thanks for your reply.
It wasn't a really a service, I just had the bike checked over for my trip and the carbs were balanced. CCT's haven't been changed.

I've checked the vacuum pipe and all seems well.

To expand on the problem, for the first time ever on this bike I'm getting vibes through the pegs and bars..so much so that my watch had stopped working by the end of the trip and it started again within a few hours of my return. Vibes are better now but still there.

It's difficult to explain, but the bike is just 'thrummy'!...I'm beginning to get a bit paranoid about it, it's running okish but just ain't right.

OK, so we can rule out any problems arising from the CCT's being replaced or the vacuum pipe not being connected where it should be.

I think imo Fireman on a Storm made a valid point about the swap over of the cans. If you still have the race cans, why don't you just re-fit them and see if the problem is still there

Chris.

[drapes]

Thanks everybody for your help.I'm going to put the race cans back on before anything else, although nothing was changed when they first went on.

Thanks again for all your thinking power....I'll let you know how it turns out (although it might not be for a week or two due to commitments).........fingers crossed!