[pigsinspace72]

So I finally got my bike all put together and went for a ride. I ended up wanting to go to a store and headed home and shut off my bike and went to get my wallet. Went back outside and the bike wouldn't start. I tried everything, choke, no choke, gas was on and going into carbs. About 20 minutes later, I went out and tried to start it and started up as if nothing was wrong. So I went for another ride. I was riding real close to home and as I was downshifting and coming to a stop, it started to loose revs and wasn't going anywhere when I gave it more throttle. I tried starting it up again and engine wouldn't turn over. I checked the(brand new) spark plugs to see if they were running lean and they looked fine. Its not the battery because it is brand spanking new and is able to crank the engine fine.

This is on a 1984 kawasaki gpz 550.

 

[MONI]

Try opening your gas cap when this happens. The vent may be clogged.

 

[hogcowboy]

^^^^ Yup, what MONI said.

 

[pigsinspace72]

Try opening your gas cap when this happens. The vent may be clogged.

I welded an f350 gas cap to my gas tank(original broke off) and the gas cap is vented and am sure of it. My gas line has an upward turn in it but I do not believe that would make a difference.

I think it could be something with ignition as it wouldn't be the starters because it shut off on me when riding.

I also can't start it up now even though it is cooled down.

 

[hogcowboy]

So you refuse to try a valid suggestion. Correct?

 

[pigsinspace72]

So you refuse to try a valid suggestion. Correct?

Well, I said it was fine. If you close the gas cap all the way, it blocks the vents. Turn it half way and it will vent and you can hear the air going in. I left the vents open on the gas cap when I went for a ride.

 

[Eye_m_no_angel]

I'm not familiar with that bike, but if it has an electronic ignition module and you suspect that, if you can get it started turn a heat gun at the module and see if that causes it to warm up and shut off. (What you describe can be a symptom of ignition module failure.) You can also do the same thing to the coils, since they can have heat related failures too.

Of course, you have to get it started first...

Have you checked to see if it's getting a spark to the plugs?

 

[slumlord]

The fact that it acted as if it was slowly starving for fuel [first post] ---

Have you checked the fuel filter or petcock screen for dirt?

If the vacuum line on the petcock is compromised,perhaps it is not maintaining the vacuum it needs to keep running. Happened to me once when a small split started on my vacuum line. When you were downshifting and coming to a stop, I would assume that the bike might have been pulling less vacuum than when accelerating

But I do not know what your bike is equipped with so sorry for the advice if your bike does not have a vacuum petcock.

 

[MONI]

I have to ask, do you know if your gas is gravity fed? I wasn't able to find out. Just a thought, you said there was an upward turn in your line. I have an inline filter on my bike and it wasn't filling quickly enough to let it flow on thru because it was on it's side instead of up & down. Caused my bike to act like I was running out of gas.

Like I said, it's just a thought. I really hope you find your problem soon.

 

[pigsinspace72]

I have to ask, do you know if your gas is gravity fed?

It is gravity fed

The fact that it acted as if it was slowly starving for fuel [first post] ---

Have you checked the fuel filter or petcock screen for dirt?

If the vacuum line on the petcock is compromised,perhaps it is not maintaining the vacuum it needs to keep running. Happened to me once when a small split started on my vacuum line. When you were downshifting and coming to a stop, I would assume that the bike might have been pulling less vacuum than when accelerating

But I do not know what your bike is equipped with so sorry for the advice if your bike does not have a vacuum petcock.

I converted it to a manual petcock and filters are free of dirt.

I did some tests today and what I found out was:
Bike was able to start right up when I hooked up an external gas tank
Gas line between inline filter and petcock not clogged
Petcock allows gas when it is in on position and refuses to let gas through when off.

When I went for a test ride on it today, I rode for about 5 miles and broke down. I would describe it as running it out of fuel. The power would cut out monetary and if I let it idle for a couple seconds and try to rev, it won't rev and will shut off. When this happened I turned off the petcock and made my way back home(luckily it was all downhill). I took of the tank and I saw in the inline filter that there was no gas inside of it. I turned the petcock back on and couldn't get gas to go through the inline filter. I took off gas line and everything and made sure there was no clogs and could not get gas to go into the inline filter. When i used my external fuel tank(the turkey baster), it would go through and ran fine.

I sincerely feel like it is fuel starvation but can not figure out why.

 

[MONI]

"I welded an f350 gas cap to my gas tank(original broke off) and the gas cap is vented and am sure of it. My gas line has an upward turn in it but I do not believe that would make a difference."

I don't know how much of an upward turn but if it is gravity fed that may be your problem. Have you tried holding the tank up high and watching your filter to see if it fills? Have you checked to make sure there isn't a blockage where the line attaches to the tank.

When you use a turkey baster are you squeezing the bulb? That would force gas to flow through the line.

 

[Eye_m_no_angel]

Is the in-tank petcock screen getting clogged?

 

[motorcyclist]

When you converted the petcock to manual did you get rid of the vacuum
system? if so make sure you plug the hole that was connected to the vacuum line with a cap or it won't run right.

 

[hogcowboy]

Almost sounds like something in the fuel tank that is covering the fuel outlet that after it sits for a spell relaxes and pulls away again. Like something that is just floating around down in the bottom. Could even be a flap of tank liner that gets pulled over. That would be very difficult to see.

 

[MONI]

I know how aggravating this kind of problem can be. It took me a few rides to figure it out. When we put that filter inline we had it going up & down. Somehow in reaching down & turning the gas on & off I must have moved it.

It seemed when my gas tank got down to about 1/2 full my problems would start. When we looked at it noticed the filter was empty. The first time or two I ended up filling the tank and finished my ride. We kept looking and Randy finally noticed it was sideways. He straightened it back to up & down and I haven't had a problem since. It was one of those "duh" moments...why didn't one of us realize this sooner.

Good Luck to you.

 

[Sigma.40]

My ZX9R had the exact same issue. If I shut it off when it was hot, it wouldn't restart for 10-15 minutes. Ultimately, I did a valve adjustment and changed the spark plugs (only about 2000 miles on them, though) and the problem went completely away. However, the ZX9R is known for the valves getting tight.

 

[pigsinspace72]

So I am still having issues. I ended up getting a prime bulb to see if it was a gas starvation issue which it wasn't. When I have been able to get it started, the performance was not good and couldn't get the bike over 70mph on flat ground and it seemed like the upper rev range had higher torque and it still seemed like a lot of power was being robbed. So I got new ignition coils and did a spark test and installed everything back together and I just can't get it started still. When I first got the bike, it started up within the first couple cranks but as time progressed over a 1 month period or so, it just got harder and harder to start.

I do not believe it has anything to do with the starter system as it supplies a good crank and wouldn't explain loss of power and it stalling on me half way through a ride.

EDIT: I can also post a video on youtube and embed the video of me trying to start it if you believe it would help diagnose the problem

 

[jag13]

Is the in-tank petcock screen getting clogged?

I gotta go with Eye on this one. If you did welding on the tank you probably have something intermittently blocking the in-tank petcock filter.

 

[pigsinspace72]

I gotta go with Eye on this one. If you did welding on the tank you probably have something intermittently blocking the in-tank petcock filter.

I flushed out the tank a couple of times with gasoline after welding. I also do not have an in tank petcock filter. With the priming bulb, i am able to squeeze it and prime the lines and carbs and when I unscrew the float bowl drain screws, gas comes out so I know there is gas in the carbs.

 

[jag13]

Yet when toy use an external fuel source it starts right up and runs fine. I'll stand by my original diagnosis (crap in tank or petcock).