Bloody shafter carbs

[RALPHARAMA]

I am at a loss as what to do with the carbs on the shafter; I suspect that there is a slight air leak from around the throttle butterflies shafts. I could be wrong, but I have tried everything else I can think of and the symptoms would tie up with that. It has a slight hesitation at very low throttle opening and also hangs slightly on the throttles - none of this is in a big way, but it pisses me right off, given the hours of work I have put into the ungrateful bastard

I haven't managed to unearth another set of carbs the same, so am considering going for a set of 34mm flat slides. It's not an area I have much knowledge of; I've not done a lot of tuning in the past. I understand that there are great horses to be unleashed from flats slides, but how would this effect the rideability of this road bike (I like lots of low down torque) and what is becoming more of an issue these days, it's thirst for the liquid platinum supplied by the arabs

I also would favour keeping the original airbox - is that doable?

If this is the best route, where best to get them from?

[freddyz1r]

Hi ralph,i'll start off by telling you i know next to sod all ( some say less).
Is it carbs for the st1100 that you cant find?
If so,do they vary on the different years?
If so,how do you identify the ones you're after ?
I have z1100st carb spares.
Contact me if i can help.
Cheers freddy

[RALPHARAMA]

Hi Freddy

They look a bit like this









They look pretty enough ....

Cheers

Ralph

[z1bman]

a one hour run on the dyno might sort it

[ADRIAN H]

a one hour run on the dyno might sort it

+1

[RALPHARAMA]

Been there none that ... They said it was an ignition fault ... Which it wasn't!

.... Though I have ordered a Gunson gas analyser to test out for BTB, which make come back with some more clues.

[z1bman]

you are wasting your time with a gas analyser as they are only used on single carb + fuel injection engines. if you have a four into one exhaust it is difficult to reach the desired c/o% settings and as far as i am aware the manufacturers did not release this information for the early normally aspirated bikes. bear in mind you have 4 cylinders + 4 sources of fuel / carburettors going into the same exhaust. you would be better off using a colour tune

[RALPHARAMA]

you are wasting your time with a gas analyser as they are only used on single carb + fuel injection engines. if you have a four into one exhaust it is difficult to reach the desired c/o% settings and as far as i am aware the manufacturers did not release this information for the early normally aspirated bikes. bear in mind you have 4 cylinders + 4 sources of fuel / carburettors going into the same exhaust. you would be better off using a colour tune

That's essentially what they test on a dyno, albeit with a bit more sophistication and the ability to load the engine. The gas analyser will allow me a reasonable idea of air fuel mixture at different throttle openings. I have a colour tune, but in reality I have never really found it to be particularly useful in real world situations. A GA will not detect individual carbs issues, but then again, nor will a dyno. I'm not really buying the GA for this particular job, but it might be interesting to see if there are any differences at different throttle openings.