Petcocks and Flowing Fuel

[LOUD MOUSE]

The tube attaches to the front right side air cleaner.
Was to allow clean air into the intake valve guide and remove any moisture.
Discontinued in 1967.
Pleaase add your location. ...............lm

Not sure I am getting the hang of this forum, can't tell if my replies are getting out or not. To Seadog, I have tired both methods, usually disconnecting the hoses from the carbs and leaving them attached to the petcock fittings. Got better flow yesterday after cleaning out the vent hole in the gas cap, but still get uneven flows, bike wont keep running. It appears to be starving out.

Along those lines, do you or anyone else know what the two small lines coming off the back of the cylinders, right next to where the carbs are attached are for? They come together in a "Y" and it seems that tube goes into one of the air filters? What impact does this have on carburation?

[mark acker]

Ok, mine is a 1967 CL77, it still had the tubes. When I ordered new air filters the metal tube on the filter to connect the vinyl tube was not present. What do I do with the tubes now? No place to route it. Can it cause problems?

by the way, I live in South Ogden Utah

[LOUD MOUSE]

Thanks for adding your location.
Some run a tube from one vent to the other and others remove the fittings and install short bolts. ...............lm

Ok, mine is a 1967 CL77, it still had the tubes. When I ordered new air filters the metal tube on the filter to connect the vinyl tube was not present. What do I do with the tubes now? No place to route it. Can it cause problems?

by the way, I live in South Ogden Utah

[G3]

Interesting topic here.
I too have experienced the vapor lock or whatever it is that prevents fuel flow. 66 CL77 and seems the left carb was the lazy one to fire off way too often. I then noticed in the manual that the Honda factory pictures show the tubing hugging up close to the carb body on the right side. So, I cut off about 1-1/4" off of each line and that seems to have done the trick. No inline filters either.

[Seadog]

Yours is a tough problem, Mark. How's the flow with the gas cap completely removed? Are the hoses completely clear and not swollen? Have you had the petcock assembly completely out of the gas tank to check for obstructions?

[mark acker]

Thanks for the replies everyone, the problem persists. One side (left carb tube), drains, the right wont.

Here is what I have done. All fuel lines have been replaced.
Carbs have been rebuilt, completely gone through, clean as a whistle, jets and throttle/air screws replaced, all O-rings and gaskets/washers replaced. Every path and orifice has been cleaned. Also cleaned the screens at the carb unions, no other in-line filters.

Have gone through the petcock multiple times, everything replaceable has been replaced. Also clean enough to eat off of (not really). Fuel tank rinsed and blown out several times, also looking clean.

I have replaced the gas cap, brand new OEM. I cleaned up the old one and put a rubber gasket on it. The new one came with a cork gasket. Taking the cap off does not seem to change much.

I am going to shorten the fuel line hoses and try to get more of a downhill shot from the petcock. The holes in the petcock leading to the tube connections for the fuel lines are SO TINY, everything has to be so perfect to get them draining.

With mine the left side line starts running (clear lines), the right just won't budge, even draining straight down hill into a pan.

[mark acker]

Thanks for the info Loud Mouse, at least I can eliminate that as a problem. I put my own foam filter on the end of the Y tube and left it routed in the air cleaner area where it was before. Hope that will work. Sounds like its not a big deal.