Float needle

[jedi50036]

I cleaned and rebuilt my carbs and now the number 4 carb is leaking fuel. It is coming from the float needle hole. Is there something that goes in the hole that i may have knoked out? i used the needles that i took out. Any ideas what i migtht have done wrong?

[DGXSER]

You float needle valve is not sealing. The float bowl will over fill and this is where it comes out. Did you use new float needle valves and seats? Did you trim the gasket from the sides of the float bowl so the float does not hang up on it?

Just a couple thoughts.

[jedi50036]

I took the bowl off and held the float up and it is still leaking around the needle. I used new needles but not the sead due to the fact that is is part of the housing and not removeable. Is there something in the hole that may have fallen out?

[CatatonicBug]

The seats are most definitely removable. They need to be switched for new sometimes. Nothing goes in that hole but the needle valve. There are 2 types of seats - the screw-in kind (with a hex head to grip), or the press-in kind, held in by a single phillips screw and a retainer piece. Sincce yours is a '79, I assume you have the screw-in kind (center of the picture, with the red washer on it).

[jedi50036]

I must be retarded or something. i went out and pulled the bowl back off and yup its the screw on type. the needles and seats wer replace about 3 months ago wich was about a month before i got the bike. I dont know what could be keeping the needles from seating but i will take the carbs back off this weekend.

[DGXSER]

First of all, use your Jedi mind skills to see if the PO was truthful with you. Or better yet, unless you know the person, assume they were not to truthful about replacing those. If they had they would look all shiney and new still and it would be obvious they were removable.

Secondly, if they are leaking consistantly with the bowls off and your pushing up on the floats, well, if it looks like a duck, walks like a duck, and quacks like a duck, your goose is a duck and those float valves and seats are probably not new.

There is an upgrade to use the seats and valves from the XV920 that will screw right in and use a viton tipped valve that seals alot better.

[dbeardslee]

+1 on the XV920 fuel valves. They seal better and last longer than the stockers. Initially you need both the needle and the seat, but when they eventually wear out you only need to replace the needles. If you're going to use the original brass floats, you may need to round off the ends of the tabs a bit so they won't catch on the lip of the seat. With Mikes XS plastic floats the tabs don't need to be bent as much, and the two parts together (valves and floats) make a very nice upgrade for the older carbs. It'll cost you about $100 to get both for all four carbs.

[jedi50036]

After taking the carbs back off i found that the needle seat was not in tight. After tightening it i now have no leak. I still have a problem with hesitation at low RPMs, havnt figured this one out. Now the bike runs like a screaming eagle. i got it to 90 MPH then desided that was fast enough.

[dbeardslee]

A low rpm stumble could be carbs, or it could be electrical. If your machine is stock with stock jetting, and the carbs are properly adjusted and clean, it might not be a bad idea to run the electrical tests at the TCI, and the primary and secondary resistance tests on your ignition coils. The alternator doesn't put out it's full voltage until around 2.2k rpms, so if you aren't getting the full 12v at the TCI when you run the tests it can sometimes cause low rpm problems. Sometimes electrical problems act an awful lot like carb problems. I suggest doing the electrical tests first, primarily because it's quick and easy, and you really want to know what's going on there anyway. If you find low voltage readings at the TCI they can usually be remedied by thoroughly cleaning or replacing electrical connectors. If you've still got the stock coils, pay particular attention to the secondary resistance readings - thirty year old high tension wires are always suspect. I sort of doubt the pickup coils would cause the problem you describe, but it never hurts to check them as well. Unfortunately diagnosing problems is a process of figuring out what isn't wrong as much as it is finding out what is. Consequently I usually do the easy stuff first - sometimes you get lucky.