My first Bandit! And the flat spot

**maggot** · 6th July 2011, 22:24

So I picked up my new baby on monday. I'm in love!

Having a hellova lotta fun on her, but I've noticed a bit of an oddity in the rev range. Between 6-8k rpm it seems to go a bit flat, the engine changes tone and I've not got much response, either side of that it's fine, and sometimes I won't have the problem at all. But it worries me. Is this normal for bandits? I suspect not, but am unused to the sounds and habits of four-cylinders.
I'm popping into the shop for a C-service asap, but am thinking I should get her checked over more thoroughly, see what they say.
Should I be worrying?

Cheers in advance

**Sable** · 6th July 2011, 22:31

Originally Posted by maggot

Should I be worrying?

No. 10character

**DrunkenMistake** · 6th July 2011, 23:09

Could be running rich? not enough air can cause it, possible air filter change/clean and then give it a shot

**Hitcher** · 6th July 2011, 23:18

I can't remember the last time I had the Technically-Not-A-Bandit over 5,000rpm. It's even got a shift light that doesn't flash at 2,500rpm.

**ducatilover** · 6th July 2011, 23:20

If the power delivery is going flat, not "soft/fluffy/boggy/wet" feeling it is too lean. 6-8k is around the time where the carb needles should be rising, you may have dirty slide/slightly sticking slides or the needle height is too low.
Has it got the factory fitted muffler?
A service may also clear it up, a bad air filter can cause all sorts of silly problems and so can poorly gapped spark plugs.

**maggot** · 6th July 2011, 23:45

I'll get to the service asap, get them to check/change the air filter and the plugs. The plugs apparently are only a couple months old though, but no harm in checking.
If the problem persists I'll start looking at the carbs, give them a good clean and balance. Thanks for the replies, much appreciated

**maggot** · 6th July 2011, 23:47

Originally Posted by Hitcher

I can't remember the last time I had the Technically-Not-A-Bandit over 5,000rpm. It's even got a shift light that doesn't flash at 2,500rpm.

Take 1000cc off yours and you've got mine

though, not technically..

**Katman** · 7th July 2011, 10:14

Originally Posted by ducatilover

If the power delivery is going flat, not "soft/fluffy/boggy/wet" feeling it is too lean. 6-8k is around the time where the carb needles should be rising, you may have dirty slide/slightly sticking slides or the needle height is too low.

Or equally, it could be worn jet needles and needle jets causing it to run rich.

**Banditbandit** · 7th July 2011, 12:30

Originally Posted by maggot

So I picked up my new baby on monday. I'm in love!

Having a hellova lotta fun on her, but I've noticed a bit of an oddity in the rev range. Between 6-8k rpm it seems to go a bit flat, the engine changes tone and I've not got much response, either side of that it's fine, and sometimes I won't have the problem at all. But it worries me. Is this normal for bandits? I suspect not, but am unused to the sounds and habits of four-cylinders.
I'm popping into the shop for a C-service asap, but am thinking I should get her checked over more thoroughly, see what they say.
Should I be worrying?

Cheers in advance

Glad you like it - I have two - a 650 and a 1250 ... Love them both.

I've never encountered the problem of a "flat spot" .. .I wouldn't describe it as a flat spot - but that does seem an appropriate way to see it.

On either bike basically anything under 110klicks to accelerate I drop into fourth ... anything below 110 to 120 feels flat if you open up in top gear (sixth)

On my 650 I've been to 180 klicks in fifth .. and it was still accelerating hard and not on the read line .. on the 1250 I have seen 200 klicks in fourth .. and starting to run out of acceleration .... but hey, at 200 klicks I had two more gears to go ... the lack of punch in top gear at around 100 klicks is a little more marked on the 1250 than the 650 ...

I found that you need to use the revs on these bikes - to corner .. to accelerate .. but they are fucken FUN if you do that ... once you get the road speed to revs balance right you'll be having such fun ..

**ducatilover** · 7th July 2011, 13:08

Originally Posted by Katman

Or equally, it could be worn jet needles and needle jets causing it to run rich.

Very good point, they run mikuni carbs don't they? Are they prone to needle wear?

**maggot** · 7th July 2011, 13:12

Took her out for a spin today, same problem still. I also noticed this morning while warming her up that a bunch of black residue was coming out of the exhaust, so by looking at that it seems to be running rich? Once warm it seemed to not be noticeable, and after the ride I came back and held a piece of paper up to the exhaust to check, and it was clean.
I've got the service booked in for tomorrow, I'll get them to check the plugs and while they're out test riding it see if they notice the lag/flat spot/hesitation/what have you. I've read elsewhere on the forums about emulsion tubes being worn on similar bikes, would this be likely to be my problem?

**bogan** · 7th July 2011, 13:22

Is it still all stock exhaust and filter etc? Does it come right again after 8k?

I wouldn't be worrying too much, but way better to get it fixed.

**maggot** · 7th July 2011, 13:24

Originally Posted by bogan

Is it still all stock exhaust and filter etc? Does it come right again after 8k?

I wouldn't be worrying too much, but way better to get it fixed.

Yup, all stock. When I took it out today it seemed to not want to get past 8k, which worried me a bit.

**ducatilover** · 7th July 2011, 13:24

Emulsion tube could do it, but, I would expect it to be rich all the way if that was the case. Does it take much longer to start when warm?

Not going past 8k could be a vacuum leak or slides not lifting or blocked main jets (Or, unusual chance of the spark being blown out)