fuel problem

[brew]

i am having a problem with i believe is the fuel system. this problem only happens during the day, never at start up or when i start it in the evening. once the bike starts, it runs fine. but, when i start to drive it starts to choke, like its not getting any fuel. most of the time it dies completely and i have to try and start it several times pulling the choke out. once i get it started its very rough, but i drive it for 200 yards and its completely fine and hold an idle perfectly. i have no idea what the problem is and have consulted a xs specialist in my area and he as no clue. any ideas???

[boyat68]

brew:

Iam just a neophyte, when it comes to motorcycles, but your symptoms seem like the slides in your carbs are sticking. I would pour a little Seafoam or WD40 or Mystery Oil in the fuel and see if this would do the trick. I would think that the slides probably need cleaning, but try the oil in the gas trick first. It cured my sticking slides on my Honda 450. I use Seafoam, but any of the other would be successful.

[mro]

the slides probably need cleaning

Have no little/effect under 3K.

Possible to seem to idle well, but not running on all cylinders.

Upon starting would check if all the headers are getting warm/hot the same. Can spray a little water on em to see if sizzle same.
(I use the "burn your hand way"). Or can pull plug wires one at a time to see if a cylinder is not firing.


Little weird that it straightens out on it's own, but could be all are firing after it warms up.


mro

[AlanB]

Hi Brew,

Before you get too worried, try putting the fuel taps to "Prime" for a few moments before you try to start it; It just makes sure that the float bowls are topped off. Fuel can't get past the vac shut-off until after the engine has started......

Are you sure that the enrichener circuit (choke!) is working properly? It is fed from tiny jets in the bottom of the float bowls; easy to miss, hard to clean!

AlanB

[TopCatGr58]

Hey Guys,

He's able to start it from COLD sitting overnight, or again cold after sitting all day in the evening, but it's during the mid day that he has trouble starting it...possibly without the choke/enrichener!?

Since he can start it WITH the enrichener, sounds like it may NOT be clogged too much, but trying to run it without the enrichener and it falls on its face. This does sound like lack of fuel, probably a clogging pilot jet circuit.

As Boyat68 said, get ye some Sea Foam and put it in the tank and run it thru, you should notice an improvement once you burn up the first tank full. Put in several ounces, not just the minimum the instructions call for!

But don't forget the basics, is your air filter clean? I didn't review whether you have a standard for special, both use vacuum controlled fuel valves, standard on the petcock, special in the octy, it may not be working properly, hence the suggestion to use PRIME to bypass the vacuum control mechanism!
T.C.

[mro]

originally posted by TC
sounds like it may NOT be clogged too much

A carb with a "clog" would be clogged all the time until cleaned.
Have not seen a petcock yet that would only work at certain hours altho can be flaky about opening and sometimes not quite opening enough but should not have regular hours


mro

[Lamric]

brew: sounds like pickup coil wires to me. Diagnostic and fix here.