TOPIC:

OK, so when the bike sits for a few days, it starts up and runs fine, then once warmed up, it wont do anything but idle. When I go to give it gas, it stubles and dies, then wont start again. What could be the problem?

whats the history of this bike?

Have you done any work on it? Has it ran in the last year? What do the plugs look like? Have you checked the timing? What about gas flow?

We need some more information here buddy.

Sounds like a fuel supply problem. Gas tank filled with rust? Carb bowls dirty? Inline fuel filters clogged? Etc, etc.

It might run ok initially until you have used up the available fuel supply or caused the crap in the carb bowls to become agitated.

I don't know what bike you have but all the advice so far is good...check your petcock as well. If it's vacuum actuated then it could be your culprit. There are LOTS of variables to consider...

Assuming it runs as it should when you first start...

Your probably running out of out of gas.
Remove your clogged in line fuel filter if you have one.
Make sure vacuum line actually opens petcocks internal valve.
Disconnect fuel line.
Disconnect vacuum line and suck on it.
You should get no air or gas in your mouth.
Fuel should flow.
If there's not enough gas in the tank it's not gonna work either.

My CB650 Hondazaki rat exhibited the same symptoms.
The fuse clips were corroded. They would heat up after a few minutes and the spark would get so weak that it would only idle. Clue was that the two jugs on the weaker coil were only firing about half the time, even at idle so their pipes did not heat up as fast. Had only 7 volts on that coil and 10 on the other. Cleaned up contacts with some 'scotch brite' and she's running great.

-Duck

its a 1981 kz1000 ltd. Ive had it a few months, when I first got it I changed the plugs, petcock and like new tank (cleaned and sealed). Ran fine for a month, then took it in for new tires and when I picked it up 3 weeks later, this was the problem. I know it is full of gas, and getting plenty, it floods if I try and start it after it dies. I think it may be the electrical problem listed below, or junk in the bowls as well, Thanks!

Check and see if your low speed diverter is stuck. The could have bumped the end of the shaft and bent it. Three weeks for tires? I get 'em in 20 minutes, plus the time it takes me to remove and reinstall the wheels.

-Duck

What is a low speed diverter?

Ok... as to the starting problem... Sounds like the tank is clean. The bike will idle but not rev and then dies. Could be the bike's spark is cut off... I would check to ensure that the plug from the right hand switch gear that connects with the wiring harness has a solid connection. There may be four prongs in the plug. Bend each just a tad and then use some dielectic grease inside the connector.

Since the problem is coming off idle, it doesn't sound like electrical but check your ground connection from the battery and in fact make sure both cables and their ends are tight.

Last, you may be running out of gas but your carbs are overflowing... Check the connections on the carb vents. There should be hoses on the two vents which are located between 1&2 and 3&4 carbs up towards the middle on a plastic connector. These vents MUST NOT be pinched or plugged. If they are, the floats will act funny. Gas will not fill, then they will overflow.

Anyway, since gas has already been overflowing and you don't have bowl overflow tubes, I would change the oil as you have a lot of gas in it. When starting the bike, if it doesn't start on PRIME at first, put in on RUN or ON or whatever position there is besides RESERVE OR PRIME. It could be that the carbs continue to pull in gas on prime and you have no spark...

What is a low speed diverter?

Meant to say start diverter.
It diverts air from behind the diaphragm to feed the start circuit in the BS34's.
I've seen two bikes where the shaft got banged and bent causing it to stick open.

Those plunger doodads you pointed me to for my GS1000 carbs as being the same on the police bikes...Thanks again for that tip. Very useful.

Now if by some magic I could replace the internal cush drive on the countershaft in my CB650 without having to split the case...I'd love to know that trick.

-Duck

Post edited by: Duck, at: 2005/12/06 22:04