Question from the Philippines-New Carbs???

[hanger10]

Hi all!! Mabuhay from Liloan, Cebu, Philippines. About 6 months ago, I found a site that sold new carbs for the XS 1100, but have googled tons now, and connot find it??? If I remember right, I think they were around 900 buks. Can anyone help me in getting a new set of carbs for a 1980 SG?? Thanks in advance, this forum has saved me!!! Take care.


Randy

[DGXSER]

Wow.....$900 for carbs??? What is wrong with your existing carbs? Alot cheaper to buy complete rebuild kits and jets than that!! Heck you may find a parts bike in whole that is much cheaper!!

Never seen new carbs though, so I can not help there.

[hanger10]

I already rebuilt!!

I got complete rebuild kits, and it turned out the jets were different sizes, and the air screws were not the same circumference! The new air screws are impossible to lean enough!!!!

Randy

[Crazcnuk]

How much of a difference? It sounds like you got kits for the wrong year/series of carb. 78/79 are quite different thatn 80-81.

As for new carbs, you can watch Ebay and try and get another used set, but that's about it.

You could try to go to some other type/brand of carb, but that won't be any easier.


http://cgi.ebay.com/ebaymotors/4-YAM...Q5fAccessories

These are the kits you need for an 80G, are these what you bought?

http://www.mikesxs.net/products-38.html#products

Part 48-0111 #115 main jet
48-0113 #120 main jet
48-0606 #42.5 pilot jet
48-1408 carb kit contains the gasket and float needle assy
48-5011 Needle kit (or right underneath is a kit with the o-ring and washer, if your needles are ok.

[Bigleo]

carbs

Dynoman.net sells replacement Keihin carbs for around $800 for the CR33 model. Realistically, it will cost you about $400 to totally rebuild your old carbs, with lots of your time wasted trying to find and ordering parts. Then you will likely find the carbs still don't run right. So why waste your money and time trying to get these low performance style carbs to work. My theory is that after all these years the slide springs have weakened to the point of screwing up the fuel metering through out the RPM range. These springs are not available. Just look at all the posts on this site about bikes running too rich. This running rich is due to weak slide springs allowing the needle jet to pull out of the emulsion tube too early. I have never regretted going to the Keihins. First off these are performance oriented carbs, not like the CV carbs. The bike starts instantly now. Has power starting at 1800 RPM and accepts full throtttle at 4000 RPM, with lots nore power than the old CV carbs ever did. And the spark plugs are no longer black.
Leo

[Crazcnuk]

Parts are readily avilable for the stock carbs, so no real reason to go nuts, just yet.

[hanger10]

Some answers for yall!

First, Yes Bigelo, I bought rebuild, complete kits, for 1980 XS 1100 SG. The circumference of the neddle valve on the air screws is abot 1/3 the size of the originals. When they were rebuilt, the old jets were almost welded in place, and 3 of them had to be drilled out. After we replaced all, I ran it, kept leaning it out until we got to the last adjustment, and still far, far too rich. We put the old air screws on the two outside cylinders, and had to richen them after the first tank of gas, and they are fine. One of the old air screws was slightly bent, but we are gonna try and get it fixed, and replace the two inner cylinder air screws with the old ones. I wish I hadnt ever even rebuilt the carbs, bike ran fine and got aroun 33 mpg, but had a miss. Well, I didnt listen to the people here until after the carbs were rebuilt, and then spliced the coil pickup, and that fixed the miss. Now, the best I have gotten is around 32mpg on the highway, running it very moderately, and get around 17 mpg in the city!!!

Crazcnuk, what kind of mileage do you get with the replacement carbs??? Thanks for all the very helpful replies!!

Randy

[hanger10]

Sorry, got turned around!!

Sorry Bigelo and Crazcnuk, got your names and questions turned around!!!First part was for Crazcnuk, and the question about the replacement carbs was for Bigelo!!

Randy

[thewiz]

I'm kinda' in the middle regarding this subject ...

and I know all you're trying to do is get your bike runnin' correctly, not be involved in a debate ....BUT .... having said that, there benfits to each.

If your bike is stock with factory exhaust and airbox, you can find an acceptable set of CV carbs that will perform adequately. GarthXS has even used some off of a newer FJ with excellent success. PM him for the details.

On the other hand, if you have (or intending on getting) a header, pods or drilled airbox, hot coils or a big bore kit. A set of flat slides or smooth-bores are a good choice. My own experience with the VM33s Mikunis on my G is much like Bigleo has described with his Keihins. I'm down to only two bikes now and I have an excellent place to work so, I think I finally have the time to tune them to perform even better in the lower rpm range than what Bigleo has described, but that remains to be seen.

Craz has the mother of all carb threads and REALLY knows what parts belong in the factory BS34s and is a good source to tap for that info.

[Crazcnuk]

"The circumference of the neddle valve on the air screws is abot 1/3 the size of the originals. When they were rebuilt, the old jets were almost welded in place, and 3 of them had to be drilled out."

I assume you mean the idle mixture screws, the ones at the top of the carb, motor side, down in 'wells'?

If so, then these aren't 'air' screws, they are fuel screws. They work the opposite of many carbs. screwing them in makes the bike lean, and unscrewing them makes it rich?

There are 2 styles of these screws, for the XS they don't interchange. The 78-79 have a really big head on them, and wouldn't fit down in the 80-81 'well'.

I don't have replacement carbs, at least ones that run, yet. I have been playing extensively with the stock ones. I get between 42-45mpg(imp) with the 80G and between 45-50mpg(imp) with the 80SG, using the same set of carbs.