Different Carb Rubbers?

[Neosophist]

The more I try and get this bike sorted out the more I realise it's been dicked about with and become a mashup of parts.

The carbs have an airleak.. if I move the airbox around the revs stop hanging etc.

3 of the carb rubbers have 1175 stamped on the top of them, the 3rd one has 1240 stamped in it.

Looking at the L model microfiche, for the L1 the part number for the rubbers is 16065-1240 which coressponds to one of the rubbers.. this has a larger bore than the other 3. The other 3 have what I think is a 30mm bore.

The carbs I have at the moment are 32mm

No idea what the smaller ones are off, as the H model is 1176 I think? *shrug*

Will using the smaller rubbers have much of an impact on the bike if I have the 32mm carbs?

The way its going at the moment and I think i'll be replacing all 4 rubbers if I can't get them to seal right.

[SOILZX]

I'm sure i read somewhere that L model imports had 30mm carbs, so perhaps the other 3 rubbers are from an import model????

[Neosophist]

I think *some* of the L model imports had 30mm carbs? *shrug*

The carbs are deffo 32mm.

Changed the rubbers this afternoon though and it's still not running right!

Every few seconds or so it's like i've pressed the kill switch, the engine bogs right down and goes to stall (sometimes it stalls) but then it picks back up again (if it hasn't stalled)

I've tried:

Plugs
Coils
CDI
Junction Box
Battery
Clean / Balance Carbs
New cam chain tensionor
Check / Set Valve clearances

Really doing my head in!

Think im going to get another set of carbs and try those next as theres nothing else left

[zimm]

the smaller inlets are "import" L spec rubbers as has been suggested ..

from experience I can confirm it'll run like toad with mismatched inlet's, but its more of a hole in the midrange than a problem low down.

when its running does it feel free-revving or tight and laboured ?

[Neosophist]

It revs cleanly, no hanging at 2000rpm

It revs up ok, runs well most of the time

I have noticed when it's hot it seems to struggle more than it does when it's cooler.

But the dodgey non-idle happens from cold

Watching some carbs on ebay, my last resort. Then im all out of options

[sinap]

We had a similar problem with our race bike, it turned out to be the vacuum hoses under the carbs these were replaced, and the problem was fixed.
Si
#91

[zimm]

replied to your other thread, as having read some of your recent posts i have a feeling thats where the problem may lie.

viewtopic.php?f=125&t=11519&p=88593#p88593

[Neosophist]

We had a similar problem with our race bike, it turned out to be the vacuum hoses under the carbs these were replaced, and the problem was fixed.
Si
#91

I blanked the vaccumn hose ports off to rule the leak out

replied to your other thread, as having read some of your recent posts i have a feeling thats where the problem may lie.

viewtopic.php?f=125&t=11519&p=88593#p88593

Cheers fella, i'll have a look

[sinap]

Sorry I wasnt clear enough in my last post, after a refresh our engine builder had blanked off the vacuum ports and removed the pipes, resulting in poor running as you described, as soon as we noticed they were missing we removed the blanks and replaced the pipes and the engine ran perfectly.
Si
#91

[Neosophist]

Oh right ok.

Well I blanked them off after it was running poorly still to no avail.

I'll get some proper fitting hose and re-attach the ports and see if that makes any difference.