model of carbs

[randy]

Mikes XS part# 48-0775



$12.00 each

[Ken Talbot]

When the ercicher circuit is working properly, it will give you a nice 'high idle' with the butterflies completely closed. When still cold, it is fairly normal for the engine to die if you crack the throttle to open the butterflies too soon. It sounds to me like you may not have any slack in your throttle cable, so the butterflies are being held open even with the idle screw backed all the way down.

[valhallan]

CARB FLOAT BOWLS

Originally posted by 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.

OK, not the greatest mechanic here, so let me make sure i understand this correctly. on the bottom of the carbs, talking looking at it from the outside, if there is a drain plug under earch of the float bowls then its a carb off an 81? is there an easy/low tech way to determine if the rest of the carb system is also an 81? if i'm restoring the bike as accurately as i can, i'd like to have all '79 type parts, although i'm probably making a bigger deal over this then it really is.

[DiverRay]

All of the carbs have a drain plug. The '81 have a "nipple" that you can put a hose on.
The "T"s are between carbs 1&2, and 3&4.The will rotate up and down, and have a 1/4" hose barb on them. If there are two on each side, the carbs are '78 or '79, just one "T" per side it's and '80 or '81.
Ray

[valhallan]

thanks

for clearing that up. these are definitly plugs, no nipples, although one is so buggered up its almost nipple shaped!.

another question, can a carb be painted if care is taken with the moving parts? i've polished the top caps and the float bowls untill they shine like chrome, but dreading trying to get into all those tiny places with a buffer, and thinking that it might look good painted also.

[DiverRay]

Yes, you can paint the body. If you look at Randy's bike pictures, and some of the others, you will see red and black carbs.

[ivers]

i'm not too sure how much slack is in the throttle cable, but i will check that when i get home.

i was trying a variety of things and in the process the bike seemed as if it was warmed up plenty, it should run without the choke on after it is warmed up shouldn't it?

also a factor i failed to mention is: after some investigation with lots of information i gathered on here and some i gathered on my own, my bike is a 79 the head is a 80 or 81 and the carbs i have been trying are 79s. from what i understand the valve diameters are smaller on the 80-81 head.

so would it be wiser to try to the carbs that were factory on the 80-81 head?
i have them, but they will probably need a rebuild kit.

thanks agian
ivers

[DiverRay]

The valve are larger on the '80/'81 heads. The PO may have taken a later head and put the '79 cam in it. That will give you a small boost in HP.
I would run through the tune up check, and then just look at the carbs. If it will not run without the choke, you may still have plugged carbs. read the Tech Tips, and be sure you pull all the jets to clean them. Just remember, you need to verify the valve clearance, new plugs, and timing is correct. If you have one thing off, the carbs will not work correctly.
Ray

[ivers]

thank you,
i have not checked valve clearance, but i suppose thats my next step.

i'll let you know how it turns out.


thankks again!