broke down and puzzled...

[SqDancerLynn1]

What you might do is take the ign cover off and ride it with the extra cooling to see if it makes a difference

[koolaid_kid]

I had this happen just this year with my GS. Turned out the ignitor was heating up and shutting down (sounds like an oxymoron, up and down). When it cooled down, I could ride again until it heated up, then nada.
Installed Dyna S, papa is happy. Just a thought.

[posplayr]

ok i'm lookin at the cap area of the tank. i did seal it with por-15, i cant seem to find any breather holes though while im pokin around with a small nail punch. my gas cap does have 2 holes in the bottom so is this how it vents?? the seal on the cap is old and i don't think strong enough to cause vapor lock, but i'm not ruling it out. it was about 45-50 outside when it happened and i had just filled up with gas and the beginning of the ride, so the cap had been off recently and no temperature change before it stalled out. the area on the outside of the tank around the filler hole is a little damp with gas. but if it was a fuel problem wouldn't it have spit and sputter before dying instead of just quit?

i didn't get a chance to check for spark as i was on the side of the road ( i will add my plug wrench to my tool kit fom now on though). all the fuses seemed ok. the coils are on a relay mod. the relay was comin on , and i have a 10a fuse in an inline holder between the battery and the coils that was not blown. i'm using the stock points with the coils, no dyna s.

i had ridden about 20 miles when it quit, and the oil temp read just above 210.

the carbs were just taken apart and cleaned about 2 months ago, and it has not sat unridden longer than a few days since i put fuel in the carbs. i did not rebuild them just a good cleaning. all the parts seemed in good condition and has been running fine untill yesterday.

http://www.thegsresources.com/_forum/showthread.php?t=168187

[jhicok]

thanks posplayer i was about to thread jack that guy untill i saw you posted on mine. on that pic what side is that hole on right or left as i'm sittin on it?? i sealed the tank and cant find that breather hole at all. i'm gonna have to drill a new one i guess. it might be causing the bike stalls and it might not.. either way i need to correct that oversight.

i did check every electrical connection i can find and they all look ok to me. no obvious corrosion or anything loose.

i ran the bike at idle- 5000 rpm ( held it to simulate highway)in the garage the other day with no problems, so i rode it to work the next night.....MISTAKE! ran fine there but on the way home we walked the last mile.. as soon as i pulled the clutch and the rpm went below 2000 it took a nap. so it'll run just fine sitting there, at the same oil temps as riding, with the gas cap on,and be fine. but i take it out on the road and it'll do it everytime after about 15 miles and the oil temp at around 210-ish.

i think i'm gonna go electrical first and put in the dyna s ( the ds 3-2 is the right one to use with the 3ohm green coils i already have right?) .. if that doesn't solve it then i'm going to rebuild the carbs for real this time and not just clean, i was going to do this soon anyway. i want to do it in steps so i know exactly what corrects this problem so we all get something out of my headache now all i gotta do is smooth over another couple hundred bucks into this bike with the wife, any suggestions on that one hahahaha

much thanks to all,
jeremy

[earlfor]

I had the same problem with my 1150 for a while. It turned out to be the ignitor box was going out when it reached a certain temperature. Replacement with a Dyna ignition solved the problem.

Earl

[mrbill5491]

Check the petcock

check your petcock, my 750 would do the same thing for some reason the engine vacuum couldnt over ride the spring in it and would eventually starve it for gas. I would slowly lose power and just stop. I then would pull the vacuum line from the petcock and suck on it to open up the valve to fill the carbs again and hopeful help it work some. It did for a bit though I eventually replaced the petcock.

[jhicok]

Sorry for the long delay on this... but it was in fact vapor locking. i installed the dyna s and it ran for a little longer than it was on the stock ignition, but in the end it was still dying out after it got up to normal running temp... so i re drilled the hole in the side of the filler neck. i've put on about 800 miles since then with absolutely no troubles at all.... plus a little more power from the dyna-s i didn't really need shhhhhhh..... dont tell the wife lol

[850 Combat]

[QUOTE=DanTheMan;1312758]You're getting too much fuel if opening the throttle makes it crank easier. QUOTE]

They always crank faster with the throttle open. Pumping losses are lesswhen it doesn't have to generate so much vacuum, I guess. Same thing with a car.

[argonsagas]

Sorry for the long delay on this... but it was in fact vapor locking. i installed the dyna s and it ran for a little longer than it was on the stock ignition, but in the end it was still dying out after it got up to normal running temp... so i re drilled the hole in the side of the filler neck. i've put on about 800 miles since then with absolutely no troubles at all.... plus a little more power from the dyna-s i didn't really need shhhhhhh..... dont tell the wife lol

Vapour lock is a peculiar thing. As noted in your case, the carb bowls can be full, but the fuel will not flow.

It is not the same as having the petcock shut off, as fuel will still fall due to gravity down the fuel line, through the carbs and the engine will sputter as it leans and then it will stop. There would be a partial vacuum created behind the fuel as it went down the line, but the distance is not enough to build sufficient vaccuum to halt the flow.

What occurs with vapour lock is that the fuel cannot flow in any part of the system. It cannot even escape the carbs as the partial vacuum halts all fuel movement. Once you stop the bike and it sits for a while, air can seep in the tank...slowly...and then you get a flow again.

In the mid-70's this was not a rare problem on GM cars.
When it happened to my wife's car on a weekend, we were well away from home and all stores/garages were closed. The cap was removed until we got home, then I drilled a hole in it, just as you did. Never had the problem again.

I have heard that it is not recommended on current vehicles as it can lead to other problems with computerised systems.