Weird problem...

[Damon]

Hi all,

I finally got round to replacing the sump on the R1 today and when I took the downpipes off each of the inside walls of the downpipes look considerably different from one another. One is coked up, two are fairly coked up and one looks really clean. It leads me to believe that the fueling must be way off??

The thing is though is that the bike feels fine to ride, idles with no problems and seems to pull as it should. I am a bit confused.

I took a picture of my exup valve too as you can clearly see the weird pattern. Could it only be running on 3 cylinders?

What do we think? running on 3 cylinders or just running with stupid fueling? or is there nothing wrong at all? How would I go about rectifying the problem?

https://img697.imageshack.us/img697/9724/img0653b.jpg

https://img402.imageshack.us/img402/1032/img0654r.jpg

The clean downpipe is the 3rd one if counting from the left. Karma cookies for all.

Thanks, Damon

[Pete.]

The grey ones are running about right, perhaps a little lean. The black ones are running too rich.

Is this a fuel-injected or carbed bike?
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Pete.]

Just spotted '99 R1 in your sig - I guess it's carbed then?

Strip-down and clean the carbs, set the float heights and balance the throttles.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Damon]

yeah it is carbed. Thanks for the quick reply. Do you think a clean and balance will sort it out? Or is it a case of getting the fueling set up with some dyno time.

Cheers

[Pete.]

It's no use taking the bike to the dyno without getting it fuelling the same across all cylinders. The dyno sniffer will only tell you the average across the cylinders because it measures after the collector (in the end can). What you have there is fuelling that varies per-cylinder. That's what you have to sort out first.

Balancing is the final step BTW, because it only affects idle. Once the throttle is open any amount it makes no odds.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Damon]

ok thanks, what is the first port of call then for getting the fueling the same on each cylinder?

[Pete.]

[Damon]

ok brilliant, thanks for your help pete

[el_oso]

acquire the Haynes manual. they are good for torque specs and float heights needle size, shim sizes etc etc
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Duke 390
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