Topic: Please, oh please, tell me how to remove a needle jet seat.

[Tretnine]

I'm stuck. All the #1 carburetors I have leak and I cannot figure out how to remove the needle jet seat... I'm pretty sure it's my problem, how the hell do they come out?

[david 750f]

This should help...
http://www.salocal.com/sohc/tech/carb/dspg_mgs/rmvndljt.htm

[Hush]

Hey David, that was a great tutorial by that guy....bet Tretnine has figured out his carbs by now.

[Tretnine]

I misspoke. I'm looking for the float needle seat. That thing is impossible. Thanks for the link, though, I've seen... but the way thing are going I need to look at it again.

[fire113]

...remove the float ball and the needle after that You can remove the needle seat.

[camelman]

The float hinge pins get stuck sometimes.  If you are having trouble with the pin, then try a spritz of Brakleen to remove any varnish from around the pin, and then gently... and I mean gently... tap it out with a finishing nail or similar.  Be VERY careful doing this.  The pin that the floats pivot on is made of soft metal

Camelman

[fire113]

...SORRY! my answer was for 750 and You are looking for 550 carbs/needleseats right?

[Tretnine]

I guess I don't know what it's called, I'm looking to take out the brass part that the seats in the aluminum of the carburetor body. The float valve slides into it, only it's out of shape or corroded and isn't working appropriately anymore. I've measured float heights and tried different float needles, but nothing has helped. It won't come out and I can't see a good way to get it out.

[fire113]

...I would try to heat the seat (ONLY THE SEAT!!!) up BUT BE CAREFULL if You make it to hot the alu will melt!!!
EDIT-->please make a pic and post it
good luck...fire113

[TwoTired]

The 550s PD style carbs of the 77-78 K models have press in float valve seats.  I don't think they can be removed without drilling/milling, though I haven't done either.

I wouldn't even think of taking them out unless I had a positive source for replacement beforehand.  I've never seen any replacements.

If a new valve needle will not seal in the seat, then the best bet is to "lap" the valve to the seat, to restore precision fit and proper shut off.  Valve lapping compound is what you would look for.

In any case, it should be common practice to turn off the fuel selector whenever you park the bike.

If it is overflowing while driving about, review the float height adjustment first.  And, be absolutely certain than the stand pipes in the float bowls have NO cracks in them (which usually leak whenever there is gas in the float bowl and a bit faster when the engine is running, and the vibration making the crack vibrate more open).

[domer]

+1 on the cracked overflow tubes! pulled the friggin carbs apart 3 times before i finally noticed it. and it still looked like a mark from machining (perfectly straight crack) clean out the bowls really well, plug one end with finger and blow through the other... its a #$%* but fixable!

[Tretnine]

I will try this. Thanks.

[Tretnine]

Hurrah! It works, thanks two! Anyway, since there wasn't anything rigid and supple enough to use to lap the inside of the valve seat I took a drill bit (the non cutting end) and put some vinyl tubing around it, just about a half inch. I used a drill bit just slightly larger than the inside diameter of the tubing, which was 1/8". Easy as hell and worked like a dream. Would recommend it to anyone with leaking floats.

[ddubs555]

Having the same problem, bowls overflowing even with a generous (too much) adjustment to the float levels.  I installed new float needles with no significant improvement, so I have to think the seats are the issue.

Can you explain this lapping process more clearly? Was the metal drill bit stuck into the valve seat or the hose?  Don't want to just poke something in there for fear of ruining the seat which looks to be pressed in and nearly impossible to remove.

[Tretnine]

To lap my needle seats I used a dremel, a q-tip and some lapping compound. Cut the q-tip off, dip it in the compound and spin away on the seat. You'll need to clean it up real nice, but with that and new float needles that took care of it. You could do it by hand or with a drill, but it'd be tedious or clunky. Pretty simple, really.