1981 cb750k Carb fuel line routing

[PRIMEWORKS]

Scratch the exhaust concern, found out the exhaust flanges were not facing the correct direction so when i flipped them the bike was way quieter and sound WAAAAy better but the concern with the idle is still there. With the choke on it goes to right around 3000 RPM then when i disengage the choke it goes way up then after some time dies. But overall sounding way better.

 

[Dave]

#1 Good to know, Lets see what happens when I get the choke thing figured out

#2 the instructions were pretty poor to be honest and included no pictures. It didn't mention anything about the flanges.

#3 No i didn't... going to try and do that now. Whats the best thing to use to plug them? or should i just cut the hose to be shorter then put a screw in the hose?

Just to clarify, are the floats in the DOHC carbs adjustable ?

#3 Major vacuum leak - Best thing to use is vacuum plugs. You can get them at the local car parts outlet. The screw in the hose will work too, dab a little bit of glue or silicone on the threads before you put the screw in to make sure it doesn't leak and allow it several hours to dry before using it. You can also fold the end of the hose over and tie it off with a little zip tie or even a bread bag tie.

Note: I'm not taking about floats. All 4 carbs need to be working in synchronization. Like them girls under water in the pool on TV. There's only a few adjustments but, you need specialized tools and the knowledge to do it right. Put it this way, I know how but don't bother to buy the tools because you only need to do it after rebuilding the carbs.

PS Anyone need a Cam degree set for SB V-8, only used once?

 

[PRIMEWORKS]

Alright so bit of a new issue. Since last posting here I've gotten the bike running great via bench tuning, playing with the idle screws, and getting new boots. My current problem or concern is with the fact that carbs are just pouring fuel out like crazy when i have the bike running. Right now I have a fuel line from the tank going directly to the carbs. When I turn the fuel on initially the bike starts with no problems. I ride for a bit and when i stop/come to a walking speed some of the carbs (maybe 1 or 2 at a time just start pouring a steady stream of fuel out from the bottom of the bowls. Not really sure what would be causing this to happen so any advice would be great!

 

[amc49]

Ethanol rust in the tank. Pull bowls and see if the red dust is in them. Or you still got float issues, the needles not sealing inside the fitting.

 

[PRIMEWORKS]

Ethanol rust in the tank. Pull bowls and see if the red dust is in them. Or you still got float issues, the needles not sealing inside the fitting.

Would the floats just be sticking in a certain position? I rebuilt the carbs and the needles weren't replaced so that could be a possible reason.

 

[amc49]

Don't try to put any rules to sticking floats, ANY WHATSOEVER will be bad. Ethanol though if bike left a week plus can make the float stick at where it was last at, the residual sugar left in it does it. Why carbed stuff open vented to the air has float sticking issues and hates ethanol. I have fits with it on my 550 since I don't drive it everyday. Pour ethanol laced fuel like a spill on say lawn mower deck while filling tank, it dries so much faster than before it's not even funny, it does that same super-evaporation thing in the carb bowls. The superfine rust left behind by it can get past almost any filter on the planet as well to mess with your needles.

 

[Tmastin]

So long story short, I'm currently attempting to start my bike up after having it sit all winter and I'm having some problems. Over the winter I rebuilt the carbs, and I just recently put in new iridium plugs. I Re installed the carbs following this picture View attachment 6644 (forgot to take pictures of fuel line routing prior to removing the carbs) and I think I may have installed the lines incorrectly because when I put fuel into the line that would be connected to the tank the gas doesn't go anywhere. The bike wants to start but obviously without the gas being properly delivered to the carbs it won't. Any help would really be appreciated!

Ok i have a question, on the diagram above, the pink line points to a hose that goes from a nipple on the 2nd carb....where does the other end connect to? You can email me at beewrangler@yahoo.com i might not see answer on this site.