I am running regular automotive gas hose straight to the metal line from my tank. I never thought about taking that metal line off. Is it smaller than the normal fuel hose? I like the wire clamps that are on it for the other wires that run through.
But if taking that off will help, I bet I could figure something else out.

The only reason I took the old oem metal fuel line off was to buy some clearance from the cylinder fins ( about 1/2"; the copper line I used was easy to bend and I figured it wouldn't melt, but rubber fuel line may actually insulate the fuel better and keep it a little cooler. 5/16" fuel line fits snuggly onto the copper so I don't think flow or volume to the carb is an issue. The fuel enricher knob has been re-routed and moved/mounted to the left side fuel tank bolt. TPS wires go up and are zip tied to the frame. The little metal clips were nice and I did use them don't need them now. Is a flat side 42 mikuni that much more tolerant of no fuel pump then the cv carb?

eblack wrote:
- why would I need to vent my gas cap when there is a vent tube running out the top of my tank near the ign. key.

Ted,

Some folks have gotten away without venting the gas cap. But most don't. The problem will be there with any gravity fed fuel setup (regardless of carb). The vent on the top of the tank is designed to be used with the fuel pump. Its just too small for gravity feed. It looks really big with the hose attached, but if you take the hose off you will see its just a tiny pinhole. Unfortunately there is another real tiny pinhole where it attaches to the tank. So both have to be enlarged to get any relief.

I spoke to one guy who drilled that existing vent out to be larger and he said it worked out. Most I know have just vented the gas cap.

The guy who did drill it out drilled right into the top of the elbow curve and down into the tank, then drilled out the hose end. Then he went back and sealed the hole in the elbow. I didn't ask for any more detail than that.

Gram

I prefer to straighten the elbow and drill straight through.

Doc

Will venting the gas cap actually make/help the fuel flow to the carb better? On second thought I don't want to cut the main tube inside the tank at all, because it'll just do the same thing when it gets down further closer to reserve level.

DocShadow wrote:
I prefer to straighten the elbow and drill straight through.

Doc

I actually did that with mine. But it wasn't for the fuel pump. The guy that painted my tank put an inner coating in the tank to prevent rust, and didn't realize he was coating that pinhole.

I nailed the outer pinhole, but I think I made a whole new inner one

eblack wrote:
Will venting the gas cap actually make/help the fuel flow to the carb better? On second thought I don't want to cut the main tube inside the tank at all, because it'll just do the same thing when it gets down further closer to reserve level.

It will, but its not needed if you keep the fuel pump. If you want to get rid of it it will help a lot.

venting the cap is a 10-20 min project, and then you'll know for sure... you can find it in the tech articles...

Looks like I'll be venting my gas cap tomorrow; I had finally got the float bowl level issue solved, and this was the first run from a full tank of gas, got down to the 1/3-to-1/4 of a tank range and it did the signiture sputter at 50-60 mph. pull the clutch in coast for 15-20 sec. carb. fills back up and carry on but easy on the throttle. After running fine since filling the tank.

PS. Gram, read my jetting profile I haven't addressed that issue yet I want to solve one issue at a time before I move on. But would a smaller main draw less fuel(out of the bowl) or is that too small of an amount to make a difference. I've had no highend problems at all (actually no problems at all but I know the jettings off.) Thanks. Ted

Just a thought on the venting issue. Even a "pin" size hole is capable of flowing a far greater volume of air than the volume of fuel being used which it replaces. The reason they use a pin size hole is to make it easy for the air to enter the tank but difficult for gas to get out. That said, the small holes can easily become plugged.