model of carbs

[ivers]

i have 3 sets of carbs and i am evaluateing the best set to use based on the information i have retrieved various places on this site.

and i was wanting to know what model of carbs i have and con not seem to find the model number printed on the carbs.

where are they??

thnks in advance!

[ivers]

also the #1 carb on the set i am currently useing is different from the other 4.
the lincage for the choke pull open the needles for the enrichener valve on #2, #3, #4, but not #1. there is a needle valve on #1, but the stem for the valve does not have a section turned down for the linkage to pull it open.

it looks factory, but i wanted to make sure.

thanks again!

[John]

You may not find the year the carbs are marked on them, but we can identify them visually. One quick identifier will be the presense of the bowl vent T's and hoses. If your carbs have two sets of T fittings on each side, then they are either from a 78 or 79 model bike. If there is only one T fitting per side, then they are of they 80/81 flavor. One way to quickly ID the 81's are to look for the drain nipples on the bottom of the float bowls. I know the bowls can be swapped around, but like I said, that is just one quick way to get some idea what year model they may be without opening them up, and seeing what parts are inside.

[John]

Originally posted by ivers
also the #1 carb on the set i am currently useing is different from the other 4.
the lincage for the choke pull open the needles for the enrichener valve on #2, #3, #4, but not #1. there is a needle valve on #1, but the stem for the valve does not have a section turned down for the linkage to pull it open.

it looks factory, but i wanted to make sure.

thanks again!

Can you take a pic and post it? That would be the best way to see what you have there.

[GNEPIG]

.. the 78 and 79 carbs have 3 holes in the ventury on the air box side and it has polished cast aluminum caps
.. the 80 and 81 carbs have 4 holes and chromed steel caps on top of the carbs

[ivers]

i will try to put a pic of the #1 carb linkage up tonight.

but, in addition does anyone know the proper float heighth?

currently they are set at 1.007" or 25.6mm

thank you

[John]

Your float setting is very close to the correct setting for the older carbs@25mm. The newer carbs should be about 23mm, but who knows what some PO may have set the floats at, so that really isn't a very good indicator.

[ivers]

this is the #1 carb linkage, or lack there of.......




and here is the linkage on the rest of the carbs


to further explain, with your information the set of carbs i am currently working with are a 78 or 79 set.
my previous post was to determine if the float heights were correct. and i thank you for giving me my awnser.

so, have you seen something like this on the #1 carb before??



thank you verry much i feel like i'm makeing progress!

[John]

This is an easy one

You will have to loosen all of the linkages that are on the choke rod attaching to the plungers (the brass pieces in the pics) and pull the choke rod most of the way out of the carbs in order to get the #1 linkage back on the plunger. All of the other linkage clips will have to be removed from the rod, but just pay attention to how they are positined on the rod. Beware! There are springs and detent balls under the choke rod where it passes through the bodies of #1 & 4 carbs. Be very careful of these balls. You should only have to remove the ball and spring from #4 carb. They are what hold the choke rod in either 1/2 or full out. The rod shouldn't have to be removed all the way from #1 carb, just enough get the rod back through the linkage. The linkage clip must be placed on the plunger first, then insert the rod through the linkage, and continue through the rest of the carbs, and put the linkage clips back on in reverse order. Good luck. One other option is to remove the plunger from the #1 carb body, and reconnect it to the linkage that way. I should have mentioned that method first. It would be quicker.

[ivers]

thanks for the rapid reply.

i have already taken the plunger and valve out of #1 and there isn't any place to put the linkage.

there isn't a place that is turned down for the clips.
it might have been broke off, and the end wore down to give it a factory appearance.

thats why i was waondering if it was like this from the factory.

so i gess i need to take the plunger and valve out of another set of carbs then?
will the small needle at the end of the plunger work from a 80-81 set?

thank you

[ivers]

here is a picture of the needle valves. the top plunger and needle is the original on the 79 carbs. and the bottom one is from 80-81 carbs.

http://putfile.com/pic.php?pic=11/31616141094.jpg&s=x2

you can see the 79 is shorter than the 80-81
kind of like it was cutt off at the mounting spot for the linkage.
you can see the chamfer that is cut on the end of the 79 plunger in this photo...

http://putfile.com/pic.php?pic=11/31616184827.jpg&s=x2

it looks factry, is there any way it could be?

if it is not, i could change the plungers out, but the 80-81 plunger shaft leading to the valve is .030" smaller than the 79, but upon inspection i don't think that would cause any problems.

any thoughts?
thank youhttp://

[ivers]

you might be able to see the end in question better here....





the 80-81 plunger does not have the same chamfer anywhere on it

thank you

[John]

Now I see...

It looks like the plunger has been broken off at the groove where the linkage would ride, and that's why it looks factory. It looks like you will need another one. I don't know if they are still available, never had to buy one, but try BikeBandit or parts n more. Maybe some one here can help you out with another plunger. Good luck.

[randy]

Mike's XS has 'em.

[ivers]

thank you john.

i changed out the plunger and the choke seems to operate properly.

now i have the carbs on the bike and i started it up with the choke on. the bike idled up to 5k and did not idle down, when i turned the choke off it instantly died. so i started it back up and it reved back up to 5k so i started backing out the idle adjustment and it idled down some and then died all at once.
i checked the idle screw and it was backed down all the way.
i assume the bike died when the butterflys closed all the way.
in additon when it was started (idleing at 5k) i tried to crack the throttle and the bike would immidiately die.
also when i was doing these trials i had the air box off, i put the air box on and tried to start it and it would not fire.

the things i have done are:

clean the carbs
paying the special attention to the idle jets and the choke circit
i also checked the passege in the boles

presycronized the carbs
useing the bred tie method (also checked it out with feeler guages)

i really haven't had it running enough to get an accurate check on the plugs.

thanks a bunch!