Finally started up but carb 2 and 3 leaking overflow!!

[Cprisco13]

So I finally got my 72 cb750 started( I literally jumped for joy). After installing new coils ( it wasn't getting spark). Now, gas is coming out of the overflow hose from carbs 2 and 3. And the bike turns off after like 10 seconds. I rebuilt the carbs so I thought everything should be fine. Please help!! Thanks

 

[dirtdigger]

if two carbs are overflowing then it is an issue with the needle and seat or the float. did you check that the floats actually float and dont sink after being in gas for a while? When it quits are you loosing spark or fuel? does it start right back up?

 

[Cprisco13]

Dirtdigger it starts right back up everytime. It runs for a while if I turn the Petcock off but if I leave it on then it overflows. It also starts revving higher without touching the throttle if I keep the gas flow on. I did not check if the float if they fill up with gas. Not sure how to do that. But I did set them evenly all the same.

 

[Cprisco13]

It may be a float needle issue because when I redid the carbs the one float wold not come off and I didn't want to break it so I wasn't able to change the float needle.

 

[Cprisco13]

So I checked the floats and they all seem to be fine. Now it starts up and runs but it gets too much fuel and starts overlowing. When i turn the fuel off it runs good and everything but then dies. Ive tried messing with the fuel mixture screws and turning them out 1 1/2 and trying different things but nothing works. Is this happening because I need the carbs synced or is it something else? I really don't want to take it to a mechanic and pay a ton of money since i dont have it and would like to use the money on new tires, chain etc.. to make it safe again.

 

[dan1951]

I had the same trouble on My 72, I think the plastic floats get so called water logged and have a little bit more weight to them. I just bent the tangs up a little more and they were OK there not set to spec,s The only other problem I had was the bowl gaskets swelling up after disassembly I just boiled them in water for about five minutes and after they cooled off they went back to original size, Good luck.

 

[Cprisco13]

Ya dan1951, I bent the things on the floats and they seem to work. So I put the carbs all back together and bam! I works! Runs nice, accellorates nice, even with fuel on. Only one problem now, instead of the overflow tubes leaking now the tops of 2 middle float bowls seem to be leaking a lil now!!!!!!ARRRGGHHHHH! I put brand new gaskets on the bowls when I redid them and all the bowls seem like they are fitting snug, so what the hell!!!! I just wanna ride!

 

[dan1951]

Had the same trouble with those too, I don,t know what to tell You, Even had to replace one of the float bowl wire retainers from a salvage yard played with the float bowls for a day before getting them right they were a PITA again Good luck.

 

[Cprisco13]

I did it!!!!!!! So aparently it wasn't leaking from the carb bowls it was the fuel line filter I put one it was loose! Just took her around the neighborhood and she was riding like a beast! Such an amazing feeling. Now I just gotta get new tires, chain and brakes. Thanks everyone!

 

[dan1951]

Glad to hear it, The previous owner, owners, Bent the crap out of all the carb retainers on mine straigtened three of them out one was scrap. Anyway ride safe, Dan.