Author Topic: problems with an ex500 (Read 4795 times)

indydan4 · « **on:** April 05, 2005, 09:29:28 PM »

My wife has a 91 ex500 with about 2600 miles on it. I had the carbs cleaned and float needles replaced last fall along with a new air filter and oil change. Now the bike runs fine until u get on the highway and run at a constant speed 4 about ten minutes then it starts 2 stumble and lurch and will not accelerate even if u pin the trottle. Its about 5-6 thousand rpms. Once u get off the highway and into stop and go traffic it will pull all the way to the redline any ideas what the problem may b.

Airmotive · « **Reply #1 on:** April 05, 2005, 10:58:28 PM »

Sounds like lack of fuel....check fuel filter, fuel tank vent, kinked fuel line.

That's my 10 second diagnosis.

B6Matt · « **Reply #2 on:** April 06, 2005, 12:06:49 AM »

Definitely sounds like it's starved for gas. Sticking floats? Clogged fuel filter or tank vent sounds more like it.

jfudo · « **Reply #3 on:** April 06, 2005, 02:07:59 PM »

Sort of sounds like your float bowls don't fill up fast enough. That is why she can run 10 minutes, then you stop and let them fill and she'll be fine. A simple thing you can do is try to run it on prime, see if that helps at all. Mostly just a way to help diagnose..

I just wanted to point to the coincidence that I have a bandit and my wife has a '95 ex500. Fun bike.

indydan4 · « **Reply #4 on:** April 07, 2005, 10:49:41 PM »

I keep hearing about this tank vent thing where do I find it. thanks

Red01 · « **Reply #5 on:** April 07, 2005, 11:08:46 PM »

In the tank.

The in-tank postion is a hard line that runs from the top of the tank (inside, in the expansion space portion), where it passes thru to the exterior, it mates to a rubber hose where it vents overboard with the other drain/vent hoses behind the gearbox.

B12Teuton · « **Reply #6 on:** April 08, 2005, 10:13:46 AM »

See if it has an inline fuel filter. If so, it's probably clogged.

stetracer · « **Reply #7 on:** April 08, 2005, 10:15:48 PM »

check the fuel petcock had the same problem on a ex500 it would stumble if you roled on the throttle at highway speeds

indydan4 · « **Reply #8 on:** April 10, 2005, 03:38:56 PM »

I checked fuel lines and removed the filler cap and cleaned it with carb cleaner no improvement. I anyone knows how 2 check the tank vent I would appreciate info. I think the hose that comes off the back of the tank and just runs down toward the ground is the vent hose I just don't know how 2 check if its working. I guess the next step is 2 remove the carbs I'd rather not though.

snofrog · « **Reply #9 on:** April 10, 2005, 04:32:13 PM »

just blow in the dirty end of it and see if there is an obstruction or constriction . air should flow freely with the cap off