Had to pull over on the highway 3 times today.... :(

[sparkfly88]

Since I got the 4th cylinder running. I seem to run outta fuel on the highway at high speeds.

If I pull over, kill it, and wait a little, it fires up.

Tank vent was disassembled not too long ago and totally cleaned up. So it can't be that.
Vacuum lines to the petcocks are brand new.

Maybe my towers or filters are clogged up?

[DGXSER]

My best guess is you either have a kinked fuel line some where, or your vent cleaning did not fully clear the path. Easy things to check, can't hurt to pull the cap back apart.

[sparkfly88]

I use that reinforced black fuel line.

Hard to imagine it would kink.

I guess on my highway ride home I'll pop the cap open and see if that fixes it.


If not.... I'm going back into the carbs to re re re re check my float Levels.

[TomB]

The carbs float seat has a small strainer/filter clipped on top before its fitted into the carb, sometimes missed unless you remove the float needle seat, these can clog up quite bad and cause fuel starvation.

One of many to look at.

Another easy check if you suspect fuel pipe kink is temporarily run a pipe direct from petcocks to carbs, if problem disappears you have a pretty good idea its a fuel pipe problem.

I once had a petcock full of crap, still don't know how it managed it as the strainers were fitted. That caused fuel starvation like you mention.

[sparkfly88]

Strainers are clean. When I rebuilt the carbs I totally disassembled.

Also went through the petcocks as well when I cleaned out the tank.

I will be dropping by a napa or something where I am and I'll replace the filters and maybe the lines with something more flexible. I honestly hate the thick black lines.

[jetmechmarty]

When you cleaned the gas cap vent, what did you replace the filter with? Every one I have disassembled had a rotten filter. I replace mine with a tiny piece of Scotchbrite.

[sparkfly88]

Lol! That was a filter?

I just cleaned it extremely well, disposed of that funk of a filter... And re assembled.

It should be a flow through now!

[jetmechmarty]

You may have blocked the vent when you disposed of the filter. I don't know that those vent holes line up. If not, the passage is now blocked. I had the problem you describe after I replaced the gasket.

[sparkfly88]

Good point, it was just a little dime sized washer with an offset hole.

It could be just sitting there not lined up with the other hole.

BUT here is the next question,

I took it to Ohio and back to Florida, I didnt have to stop once.

[jjz28]

maybe when you pushed that thick black line on, it got tore on the inside by the petcock and is slowing your fuel flow. I hate the thick line. I have line from lowes that is see thru and routed it so it cant kink.

[sparkfly88]

Well, I just rode for an hour at 85mph average.

Not a single problem. Rode with the gas cap open.

Now I know what to attack.

[jetmechmarty]

I cut out a tiny piece of Scotchbrite for a filter. It won't rot. I have three Yammies running with that fix. The problem usually goes unnoticed until the gas cap seal gets replaced.

[DGXSER]

I've done the scotchbrite pad as well. Very similar in material and breathing to the original filter material.

[jayel]

lawn mower shops will have the clear or colored (yellow, blue, green) tygon lines, see through, doesn't get hard like PVC line does, will kink so you have to be a little careful running your lengths

[sparkfly88]

So, I think its a fuel level issue...

I had my cap open and at around 88 miles or so, it started sputtering anyway.

I fueled up, shut the cap as an experiment, and its been running fine since.
So, it seems to only pitch a fit when Im a little lower on fuel