Hard Start In the Morning and Missing Fuel

[BA80]

Sometimes just riding the damn thing will fix little stuff.

[3Phase]

So, now you have it narrowed to 2 carbs. That fuel has to be going to the cylinders, the air box, or the earth.

Greg, the manifold boots and intake valve tract were clean when I had the carbs off but that really doesn't mean jack after running the engine anyway. The airbox and intake boots looked clean when I had the carbs off but I'll check them again. I'd have to send some oil to Blackstone for a UOA to see if the oil is contaminated with fuel.

I'll pull the air filter and check the airbox boots again but I think <cringe> that the leak is slow enough that there's not enough fuel in the line and filter for the fuel to make it all the way from the carb to the airbox or the cylinder(s) before it evaporates.

I have not yet tried leaving the fuel taps set to Prime to see if I can empty the tank into the cylinders or all over the floor. Some other time, perhaps.

[BA80]

Park it with the nose up hill and everything will go to the airbox if the floats are where it's coming from.

My driveway is uphill and the SF will fill the airbox if I forget to turn off the valves.

[3Phase]

No leaks or are the carbs just faking it until I look the other way?

I left the bike out on the sloped driveway overnight, nose high, with the fuel taps on Prime and the airbox lower half removed to see which carb, if any, was losing fuel but there were absolutely no leaks anywhere.

Apparently the carbs decided to band together and act all normal and stuff now that I'm eyeballing 'em so, of course, there was not a drop of fuel missing from the lines or filters and assembly grease wouldn't melt in there precious little mouths. The engine fired up almost instantly when I pressed the Start button. I really, really, really want to kick it now.


Sadly, one of the vacuum gauges in my homebrew carb sync tool seems to have gone 'sproing!' yesterday. It won't return to zero and it just doesn't read right any more. Okay, all together now -- "Just one more thing!"

I quit dinking around and splurged on one of those fancy K&L vacuum sync gauge sets on the web for half of their regular retail price.
I could have bought a Morgan Carbtune for about the same money, split, stacked, and delivered but I like looking at a set of nice round gauges instead of a stalk of writhing stix and the seller is practically right next door in Nevada instead of the U.K. so they should be here after the 4th of July.

In the meantime I have to go apply some voltage to a fuel tank and dunk it in Evapo-Rust until it comes clean. That should keep Columbo and me out of trouble for a little while.

[BA80]

Apparently the carbs decided to band together and act all normal and stuff now that I'm eyeballing 'em

Ain't it funny how they seem to do that very thing.

A friend of mine, I won't mention Ivan's name, had a float valve that wouldn't quit leaking and he got really upset and smacked the carbs with a hammer.................HARD! He had to fix his choke lever but he hasn't had a problem since.

[3Phase]

Given the size, knowledge, and singularly focused determination of the friend with the hammer I am not at all surprised that those poor innocent carbs are still ringing right along like stunned (but suddenly very happy and well behaved!) little fuel-filled bells!

What a bummer about the lever though....

[BA80]

The lever is permanently disfigured but still functional.

[WMarshy]

The lever is permanently disfigured but still functional.

Arnt we all lol.

[3Phase]

Hey now! I resemble that remark but it was a cement truck driver what done it, not a hammer!

[skids]

Hey! I was a concrete truck driver, but I didn't do it! =8-D

[unicorncomputer]

Did you find out what the problem is/was. I am having similar issue with my number 1 carb. I will find gas on the bottom half of the carb, replaced the bowl drain washer, will do the bowl gasket next.

I left the bike out on the sloped driveway overnight, nose high, with the fuel taps on Prime and the airbox lower half removed to see which carb, if any, was losing fuel but there were absolutely no leaks anywhere.

Apparently the carbs decided to band together and act all normal and stuff now that I'm eyeballing 'em so, of course, there was not a drop of fuel missing from the lines or filters and assembly grease wouldn't melt in there precious little mouths. The engine fired up almost instantly when I pressed the Start button. I really, really, really want to kick it now.


Sadly, one of the vacuum gauges in my homebrew carb sync tool seems to have gone 'sproing!' yesterday. It won't return to zero and it just doesn't read right any more. Okay, all together now -- "Just one more thing!"

I quit dinking around and splurged on one of those fancy K&L vacuum sync gauge sets on the web for half of their regular retail price.
I could have bought a Morgan Carbtune for about the same money, split, stacked, and delivered but I like looking at a set of nice round gauges instead of a stalk of writhing stix and the seller is practically right next door in Nevada instead of the U.K. so they should be here after the 4th of July.

In the meantime I have to go apply some voltage to a fuel tank and dunk it in Evapo-Rust until it comes clean. That should keep Columbo and me out of trouble for a little while.

[3Phase]

All good this morning

Did you find out what the problem is/was. I am having similar issue with my number 1 carb. I will find gas on the bottom half of the carb, replaced the bowl drain washer, will do the bowl gasket next.

If that doesn't fix it, check the float bowl itself for cracks. I had a set of carbs with one leaky float bowl that had a hairline crack. It looked like someone used a 300lb 1" drive impact gun to put the drain screw back in the float bowl and for some reason it cracked the bowl around the drain.


I believe the starting and fuel loss problems are fixed for now. The fuel filters were both full of fuel, no air bubble, and Columbo just fired up on the first hit and idled smoothly (for certain values of 'smooth') at ~450/500 RPM when I let go of the enrichener.

I need to fix the '80G carbs or put on a handlebar lever so I can use the XJ carbs without messing with the enrichener by hand. Right now I have the enrichener bar reversed so the XJ's little cable fitting is on the left side of the carbs so I can just grab it and hold it out while the engine starts but it's kind of annoying to stand there and hold it while the engine warms up.