1979 MKii No workie...

Would first test ride with fuel tank cap ajar to determine whether this has any effect on the problem. If so, then worry about clearing the vent.

Good Luck!

Patton wrote:

Would first test ride with fuel tank cap ajar to determine whether this has any effect on the problem. If so, then worry about clearing the vent.

Good Luck!

Precisely!!

Okay, so I did that tonight and ended up pushing my bike back home.

I set out tonight with the electric starter not working. I checked the battery and got full voltage. So, I moved to the kick starter and first kick she roared to life. I let the bike run for 5-10min to warm up a bit. It idled fine and I revved the motor a couple of times with no issues at all. I got on the bike and headed to the next neighborhood over in case it stalled again, I wanted to be close to home. I had no issues riding around the neighborhood, so I moved on out to the open road. I headed down the road and probably made it about a 1/2 of mile and then I was rolling along at about 60mph and the bike just started to slow down.

I tried down shifting and got nothing. The bike just died. It was not like running out of gas where the bike studders or surges. I tried opening the gas cap, riding with it open, made no difference.

As soon as I stopped I tried to kick it over and the bike did nothing. It was as though I did not have spark or anything. I tried messing with the petcock from prime to res to on.

I was wondering if there could be something that got too hot while the bike was running that would overheat and quit working. I just think there could be something that I am not thinking about.

The reason being, as soon as the bike would sit for a bit or something, I would turn the bike on and give it a kick start and up and away she would go for another 1/2mile.

So, close guys, has to be something dumb.

Thanks,
Jason

One thing that I forgot to add...

the first time that it quit on me, i pulled over to the side of the road and waited it out as always seems to be the case. When I finally got it started again, I took off. I thought maybe if it was a fuel line problem I could "Rev" through it. I took straight to 6k rpms where it promptly died again and I pulled over 30 yds down the road.

The weird thing is, that idling does not seem to be a problem.

Jason

Have you checked your coils? My police bike was doing this exact same thing. I finally checked the coils out. Sure enough one was bad. I guess when it got hot enought it cuased it to short out internally or something. So I replaced them with dynas 3 ohm coils. Fires off in about one revolution of the starter now....

Bullitt03737 wrote:

Have you checked your coils? My police bike was doing this exact same thing. I finally checked the coils out. Sure enough one was bad. I guess when it got hot enought it cuased it to short out internally or something. So I replaced them with dynas 3 ohm coils. Fires off in about one revolution of the starter now....

He's actually already got the dyna 3 ohms on there, but what's to say those can't go bad? I'm thinking it might be fuel starvation, but very well could be ignition. Like you said, it gets hot and shorts out, then cools off for a while. Very interesting...

Guess I didnt catch that part. Haha. But ya whos to say they cant go bad to? That may mean theres another problem somewhere else to fry up new coils.

Someone also mentioned in this topic or another I cant remember. But When a bike does what yours is doing. Its a fuel starvation. what happens is it dies becuase its out fo fuel. After it dies you sit there and fiddle with it and more fuel dribbles down into the bowls allowing you to restart it for awhile. Moral of the story double check your fuel supply.!

I will try to look into the fuel starvation thing some more. How can I confirm my vacuum line is working properly?

What other things should I be checking?

Jason

You are running a vacuum petcock? If so, put it on "PRIME" and try it out. That will tell you if it's vacuum/diaphragm related. If it's not a vacuum, just put a jar under it and open it up. Should come out nice a easy.

Could be float level too, but we're giving WG the benefit of the doubt on all carb issues.

Would remove fuel tank; dump fuel; remove petcock; clean the filters on the petcock tubes that go up inside the tank; disassemble and clean petcock; before reattaching petcock to tank, add some fresh gas to tank, slosh it around and dump out to flush tank; repeat tank flush exercise; reinstall petcock; remove and relace in-line fuel filter.

All this because sometimes crud or grit is suspended in the fuel inside the tank. Where it is drawn to and hovers around and collects on the petcock intake tubes up inside the tank. This can restrict fuel flow and result in the problems described (akin to a blocked fuel cap vent). Same with a dirty partially blocked in-line fuel filter.

Am still harping on the fuel supply aspect because fuel starvation (from any of the above reasons) is IMO far more common and therefore much more likely than a cycle of both coils overheating enough to fail and then cooling off a little. Coils might end up being the answer here, but am still betting my nickel on fuel starvation instead of faulty coils.

Anyhow, it can't hurt to assure an ample supply of good clean fuel to the carbs.

Good Luck!

Almost forgot to mention -- don't need a temp gun to check the exhaust pipes. Just use a common household hand-held spray water bottle to mist the exhaust headers on a running engine (or engine that has just been shut off). The water will instantaneously sizzle and vaporize on the pipes exhausting a properly combusting cylinder. The water will just collect and run down a pipe exhausting a non-combusting cylinder.

Good Luck!