Only starts when primed

[Anonymous]

The previous owner of my new GS1100GL has told me that when the bike sits for about 2 weeks, it can only be started when it is flipped to prime for about thirty minutes. Is this a problem or a typical thing done on these GS's? What could I do to remedy this?
Thanks.

[focus frenzy]

the only remedy would be not to let it sit that long, these bikes were ment to be ridden not parked.
actualy the carburators are not sealed, they have open vents so some fuel will vaporize out of the bowls, these carburators can be finiky about the fuel level in the bowls, so when the bike has sat for a couple of weeks to a couple of months you may have to turn the petcock to prime for a few seconds (not thirty minutes) to allow the fuel bowls to fill back up to the proper level.

[earlfor]

If the bike has been sitting for a couple days, I usually allow about 10 seconds for the float bowls to "top" themselves off and I go ahead and start the bike with choke and in the prime position, let it run for a minute then switch to run/on.

Earl

the only remedy would be not to let it sit that long, these bikes were ment to be ridden not parked.
actualy the carburators are not sealed, they have open vents so some fuel will vaporize out of the bowls, these carburators can be finiky about the fuel level in the bowls, so when the bike has sat for a couple of weeks to a couple of months you may have to turn the petcock to prime for a few seconds (not thirty minutes) to allow the fuel bowls to fill back up to the proper level.

[Anonymous]

Be sure to check your vaccum line! Ther is a hose that is connected to the petcock and one of your carbs, this is ment to suck vaccum in the petcock, making the fuel flow to the carbs. (there are to hoses from your petcock, both fuel and vaccum).

[Anonymous]

No Prime on the Petcock

I was out of town for a week. When I got back, I tried to start my '79 GS750, and had a horrible time of it. The kicker is that I DON'T have a PRIME position on my petcock. It only has RUN and RES. What's up with that? To get it to go, I usually have to kick the starter 20-50 times before she'll fire. Any better suggestions?

[Anonymous]

I've noticed there is no real difference between the flow of fuel from the petcock in prime or run position (if the vacuum function is working correctly). Check that hose from the petcock to the #2 carb for even little cracks and replace it if at all questionable. Heck, even aside from the petcock function, a vacuum leak isn't going to be liked by the engine either.

30 minutes, as part of this equation, doesn't make any sense. In the prime position, it should take 10 seconds max to bring the floats up to level.

Roger Moore

[Anonymous]

xcvii...

You may have an aftermarket petcock that has no vacuum safety function. That's really all it is, a safety feature. Pull the hose and put it in a jar and see if it flows. You may have an OFF position though, so see if you can turn it to any position other than ON or RES first.

Roger

[Anonymous]

xcvii...

You may have an aftermarket petcock that has no vacuum safety function. That's really all it is, a safety feature. Pull the hose and put it in a jar and see if it flows. You may have an OFF position though, so see if you can turn it to any position other than ON or RES first.

Roger

I'm pretty sure it is stock. I needed to replace the original tank due to severe rust and dents, and the "new" one had exactly the same petcock. It holds gas until vacuum is applied, in both the RUN and the RES position.

[Anonymous]

Well, I guess this type of petcock assumes you can crank it over about 20 times to fill the float bowls...if they're empty...since that's where you'll be getting the vacuum from.

Roger

[earlfor]

Re: No Prime on the Petcock

Hmmm, thats strange. My 79 GS 750 had the original petcock and the 81 GS 750 I got for parts also has its original petcock and both of them have prime, run and reserve positions. 20 to 50 tries everytime you want to start the bike is absurd. If nothing else, it will insure that the starter has a very short lifespan. Considering petcocks are a lot cheaper than starters and the aggravation factor also, I would buy a petcock that had a prime position. Then too, being a 79, you do have a kickstarter. :-) That'll save the electric starter, but at the cost of your leg. :-)

Earl

I was out of town for a week. When I got back, I tried to start my '79 GS750, and had a horrible time of it. The kicker is that I DON'T have a PRIME position on my petcock. It only has RUN and RES. What's up with that? To get it to go, I usually have to kick the starter 20-50 times before she'll fire. Any better suggestions?

[Anonymous]

Re: No Prime on the Petcock

Considering petcocks are a lot cheaper than starters and the aggravation factor also, I would buy a petcock that had a prime position. Then too, being a 79, you do have a kickstarter. :-) That'll save the electric starter, but at the cost of your leg. :-)

Yeah, my right leg is starting to look like Arnold Schwarzenegger. Actually, as long as I ride it daily, it starts on the first kick.

I think I will look into another petcock. I think it was just a peculiarity of the "L" models. Seems like they've got several odd features.