How do i check what my carbs need?

O

olly

Senior member
20221119_182451.jpgI bought these lightly used and (undisclosed till I had paid) slighlty incomplete carbs because my they were local and my bike ran rough. So much of the bike is original I feel these spoil it. How do I go about appraising the old ones and figuring out what, if anything, they need please?
 

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Slides are fit for the bin.
Try a new slide at 1/4 lift in the old carb body. If the slide can be moved laterally in the carb, carb is dead unless you can find somebody to sleeve it. The female coupling original carbs may look better but a bike that runs rough and risks holing a piston is no good. If you go ahead with the old carb bodies, new old type slides are hard to source. New model slides need the idle ramp modifying.
Or fit Mikunis. :-)

Paul
 
I've modified dozens of these new slides to fit the old-type bodies, no issues whatsoever. Very little of the ramp is removed, enough left to last longer than the rest of the slide.

piet
 
There are 2 problems with machining the slides.
A/ you remove the top of the ramp so restrict amount of lift you can get with the tickover screw so it can only operate on the bottom of the ramp
The more of the ramp you remove the further the adjustment screw has to wound in before it starts to lift the slide.
B/ You remove the size of the ramp the tickover screw acts against so if you let the throttle snap shut a few times you will dent the ramp which in turn alters the tick over
Eventually you just cant get enough adjustment on the remaining/dented ramp to get a tickover.

Not a problem on triples but a problem on twins which use the ramp.
 
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what slides do you need, I have boxes of them, some of them have only run for ten minutes on a dyno.
sent to you first, only pay if delighted.
CLEM
 
The dark grey colour and a few other details suggest to me that they might be modern replacement carbs (ie 'new type'). Might have 'old' slides in 'new' carbs?
Dellorto UK are extremely helpful, if you have a bit of a mixed bag and not sure, give them a call and/or email them some photos. They can identify the parts visually with much more certainty, and advise what you need to make them work together properly.
 
breganzane said:
The dark grey colour and a few other details suggest to me that they might be modern replacement carbs (ie 'new type'). Might have 'old' slides in 'new' carbs?
Dellorto UK are extremely helpful, if you have a bit of a mixed bag and not sure, give them a call and/or email them some photos. They can identify the parts visually with much more certainty, and advise what you need to make them work together properly.
Click to expand...
The old ones would have a female coupling of course.

Paul
 
Paddy said:
There are 2 problems with machining the slides.
A/ you remove the top of the ramp so restrict amount of lift you can get with the tickover screw so it can only operate on the bottom of the ramp
The more of the ramp you remove the further the adjustment screw has to wound in before it starts to lift the slide.
B/ You remove the size of the ramp the tickover screw acts against so if you let the throttle snap shut a few times you will dent the ramp which in turn alters the tick over
Eventually you just cant get enough adjustment on the remaining/dented ramp to get a tickover.

Not a problem on triples but a problem on twins which use the ramp.
Click to expand...

Hey Paddy, welcome back.
 
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