Another Keihin FCR carb question

[Hellwig]

I'm not sure if this is the right location, so mods... you know what to do if not.
Ive got a carb overflow dribble and I have replaced the needle float valve with a new keihin valve, corrected float height to 9mm, it WAAAY off. Still dribbling.

Does anyone have a procedure for removing the valve seat without destroying them?

I can get it out but am reluctant to try until I get a replacement. Everytime I have removed them in the past they were bent.
I have a feeling the o ring is toast, and I have those on hand.

I read somewhere on TT that you can use a slide hammer, but it's an awfully small hole/ delicate little guy. Also read someone used a valve reamer to clean up the seat? I'm intrigued.

Thanks again

 

[bwdmax]

I have cleaned the seat with a q-tip and lapping compound.

 

[beefsalad]

OEM FCRs do not have a removable float valve seat, aftermarkets might. I'd try the q-tip trick @bwdmax suggested as I've had good luck with it on my FCR39

 

[Hellwig]

This is my second oem fcr and I have replaced the seat before, but not without destroying the old one. Since I'm waiting on sudco to send my $100 handful of spares including a couple new seats, I decided to "build" a puller and it worked very well without damaging the seat at all. 2 pieces of coat hanger wire, beat flat and ends bent and ground into hooks that would both fit into the valve from the top, popped it out like butter.
Oring looks toasted like I figured, so cleaning the seat, then gonna try BWD method with the qtip and lap compound. More later

 

[FE_Rex]

This is my second oem fcr and I have replaced the seat before, but not without destroying the old one. Since I'm waiting on sudco to send my $100 handful of spares including a couple new seats, I decided to "build" a puller and it worked very well without damaging the seat at all. 2 pieces of coat hanger wire, beat flat and ends bent and ground into hooks that would both fit into the valve from the top, popped it out like butter.
Oring looks toasted like I figured, so cleaning the seat, then gonna try BWD method with the qtip and lap compound. More later

View attachment 357186

View attachment 357188

If you don’t have lapping compound you might try toothpaste. I have gotten more than one dribbling diesel tractor injector pass a pop-test by putting a little toothpaste on the needle and spinning it real slow in the nozzle seat with a drill

 

[Hellwig]

Toothpaste is an excellent idea, thanks for the tip!
Seat is now cleaned up and shiny inside and out.
For those that don't know, there is a screen underneath the seat that snaps onto the end of it. In the past, I have removed and left it out because it was damaged, but this one looked pretty good, I cleaned with brake cleaner and air and snapped it back on, to keep trash out.

This time I am going to connect the carb to the tank without installing in the bike and check for leaks before putting it back on the bike.
I am not real quick but I get there eventually.

 

[beefsalad]

This time I am going to connect the carb to the tank without installing in the bike and check for leaks before putting it back on the bike.
I am not real quick but I get there eventually.

If I've learned anything about fixing a float, its that its worth bench testing before mounting it on the bike.

 

[Hellwig]

so far, I have not been able to make this carb stop dripping, I have twice removed the valve seat, first time was a gentle hand polish with qtip and fine lapping compound, second time a much heavier session with multiple qtips, the coarse compound and my drill, then repeat with the fine compound.
I even changed the needle valve with the one that had been in there just to maybe rule out the possibility of the new one I had in there possibly having a defect.

Next up, an old needle valve and lap compound, although I am not sure how I am going to connect it to a drill yet. I will have to see what I can figure out. I may also try to increase the float height to 10mm instead of 9 just to see. Work has had me pretty busy, and I haven't had a lot of time for this, so maybe the new seat and needle will show up and I can just replace them instead.

 

[Hellwig]

Update: Polish, needle valve and seat, nothing solved this issue. (This bike has made a pretty good fool of me to date)
I finally removed the bowl again, and filled up the overflow hose and was able to realize the problem is the brass overflow pipe is not sealed to the bowl!

Searches for new bowls yield $160 Keihin replacement parts, but the kicker is, they don't have a overflow pipe! Apparently this is omitted on new production carbs, in the name of environmental concerns, so if there is an excess of fuel it will not spill out, in favor of draining into your cylinder.

I'm just happy I found it and will forgo the new bowl in favor of a repair.

the road goes on forever and the party never ends...

 

[bwdmax]

Good catch. Thanks for the info, you might have saved me some trouble down the road.