More help

[Camulus]

Right......think I've traced most of the problems.

Carbs - tiny, tiny pin prick hole in the float on #1 so float was filling with petrol and not....well floating.
- two diaphrams have small holes in them

Advance/retard mechanism not holding vacuum

Now I'm hoping to be able to repair the carbs to last a few months until the winter strip down and then replace them (please somebody, find a straight swop!) but I don't know what to do about the A/r mechanism. I seem to recall reading that a more modern system, coupled with new carbs works but can't find the thread.

Any suggestions?

[DGXSER]

Looks like you have an 80 model bike. Being across the pond, I assume you still have the later model carbs in that bike. I found a new slide for mine with the diaphram for about $50 IIRC. The plastic float having a hole is very unusual, but I happen to have four of them sitting in a bag in the work shop.

[James England]

Right......think I've traced most of the problems.

Carbs - tiny, tiny pin prick hole in the float on #1 so float was filling with petrol and not....well floating.
- two diaphrams have small holes in them

Advance/retard mechanism not holding vacuum

Now I'm hoping to be able to repair the carbs to last a few months until the winter strip down and then replace them (please somebody, find a straight swop!) but I don't know what to do about the A/r mechanism. I seem to recall reading that a more modern system, coupled with new carbs works but can't find the thread.

Any suggestions?

I'd leave it standard. The advance diaphragm assembly is easily replaced. I've sold three of them on eBay for less than £25 over the last two years. They do come up regularly. Even NOS.

Slide diaphragms are best from the USA and it's easy to replace them on your existing slides.

A straight swop may not be best, you know. Personally, I would strip and clean the carbs throroughly, replace the four diaphragms and also the float needle valve assemblies. Check the small hemispherical filters above the float valve assemblies.

Are your inlet manifolds OK?

A full carb strip and clean is easy enough if you don't split the bank of carbs. You need compressed ar too. Vital for cleaning passageways

[WMarshy]

I agree with everything James said but, if your still considering carb swap then the ZRX carbs are a close as it gets for being bolt-on. Your over the pond so if you could dig up a set off a Yamaha XJR they might work as well but we have no idea if they will require any more or less modification than the ZRX... Shop around on ebay, you should be able to buy new diaphragms, plastic floats and you advance mechanism for cheaper than a set of used ZRX carbs...

[Camulus]

Okay.....well I think the carb repair will hold (brass solder on the float and rubber glue - cement you call it I think, which is something completely different over here) and a s/h vacuum unit.

Overall, unless a different bikes carbs were a straight bolt on and had the advantage of being newer I doubt that I'll bother - seems to me it's a minefield even trying to put on pod filters and get these things running properly!

Thanks for the input and I'll wait to see what's next to fail (oh...other than a fork seal which let go last week and on inspection must have been put in when God was a child!!)

[mikubuilder]

careful about adding any weight to the float...it will change it's floating ability...make sure you check fuel level with carbs upright, and level, with a piece of clear tubing attached to the drain...

just my .02

[James England]

Okay.....well I think the carb repair will hold (brass solder on the float

Not a good idea. You'll affect the weight of the float and it will alter the float needle height. I'd buy a new float off eBay... or a good used one. I would definitely not use a float that you've soldered yourself.......

BTW, looking at the carbs on my XJR1300, I reckon they'd fit directly onto an XS1100

[WMarshy]

BTW, looking at the carbs on my XJR1300, I reckon they'd fit directly onto an XS1100

Common man, dont tease us like that.

[Camulus]

Not doing the soldering myself....trusting to a local shop.

I've also got a secondhand set of carbs coming to either mix 'n match or refurbish over winter.

[James England]

Common man, dont tease us like that.

Honestly, I do think they'd fit straight on! The look similarly spaced, similar manifolds......I reckon a set would fit virtually straight on..... I've seen them on eBay for less than a set of XS1100 ones and, of course, they aren't 30 years old.....

[petejw]

a cpl of guys over here are using the xjr carbs,
but they still need to be rejetted.