crusing problem??? very fishy

[kurt12345]

i have a 81 gs1100ex with abotu 26k on it, and i have this problem when iam crusing on the freeway for about 10 miles or more it feels like one or two cyclinders cut out and i cant accelarate it just bogs and holds its speed then the power will cut in and out while i have it wide open, then it feels like something un clogs it self and i have power and accelarates then it will be fine for a few mintues then it cuts out again, it only does this on the freeway when i hold a stedy speed , but i can go hit the back roads reving the crap out of it for hours without any problems and even crusing back roads with out a single problem, just when i hit that freeway it cuts out i have no clue whats going on

 

[Nessism]

Sounds like a petcock problem; not flowing enough gas.

 

[kurt12345]

i rebuilt the petcock is there some way to test to see if its flowing properly??? is there like a certain amount thats post to flow??

 

[Griffin]

Check your carburetor floats both for height, and also to see if they swing freely. One or more of them could be getting "hung up" at steady speeds because the gas consumption is low and gradual.

 

[kurt12345]

the carbs have been apart and cleaned ,they seem to be free, i just noticed the bike was on prime on the petcock the howl time can that cause a problem??

 

[Griffin]

If everything is sealed properly, no. That being said, the prime position allows free fuel flow at all times, so you're relying on the seal between your needles and seats to stop fuel flow at the proper height at all times, regardless of vacuum level. If you ahve too much gas in the bowls, you could be running rich, wich would hurt your power output, especially if your plugs are fouling. I doubt if it's what's causing your problem, but run the bike for a while with the petcock to "on" and see if it makes any difference.

 

[kurt12345]

i will try it tommarow, yeah it never did this before but yeah iam affraid to drive it far thinking maybe its a ignition problem likes it going to cut out and not come back. but if it was ignition it would do it on the back roads, so you guys think its a carb or fuel problem

 

[Griffin]

Actually, I'm more inclined to think ignition, but fuel would be easier to verify first.

My GS750 was acting almost identically to your problem, but it was more random, not just at steady speed. It drove my nuts for quite a while, but eventually it cut out in my driveway. I immediately ran a quick test of the ignition components, and found out that one of my coils was reading ultra high resistance, but only when hot. After it cooled down for a bit, it read fine again. I replaced the coil, and everything seems fine now.

 

[kurt12345]

thats what confuese me , i went for a ride with a budy of mine and we riding around the back roads for 3+hours 50-100mph all the time, not a single problem then we hopped on the freeway then it cut out a few minutes after wards, its like somebody stuffed a rag in one or more cylinders , when its cut out and bogging i keep the throttle wide open then it cuts in and out then all of a sudden its like somebody took the rag out and runs fine all the power in the world but only for a few mintues then when i go back to cruising it cuts out again, i half tempted to replace the howl iginiton with a dyna system and coils

 

[Griffin]

Have you checked the resistance on your coils, and examined the connections betwwen the plug boots and wires? A lot of ignition problems originate there.

 

[kurt12345]

ok will check it and repost, thanks for help griffin i wann get this thing fixed by sunday cause i wann take it to the drags which is about 50 miles or so away i want it to make it.

 

[bwringer]

It's definitely a good idea to check the ignition function while hot, especially if it's cutting out on two cylinders.

Inadequate tank venting can also cause fuel starvation, but it would affect all cylinders.

It's hard to tell from here which problem you have.

In any case, it can't hurt to make sure the gas cap is venting properly, and it only takes a few minutes. Just turn it upside down on a clean, well-lit surface, take out the screws, and clean out any deposits you find. Make notes so you get the spring and check ball back in the right places.


In chilly, humid weather some bikes can also experience carb icing after long periods of steady-state throttle. I don't know if this happens to GSs very much, and we don't know what your weather has been like.

 

[Smokinapankake]

Only help I can offer is to be sure the throttle cable isn't hanging up on something. Verify spark in all holes, verify steady fuel flow, then check coils. Particularly when hot. Don't know if that will help.

Good luck.

 

[82Shafty]

This is totally a dis-function of the EGR system... Surging while at cruising speeds.

Just kidding... Try adjusting the choke out a bit when she stumbles on you to see if it makes any difference or not.

If it comes back to life with choke, you are starved... if no matter where you have the choke and it's stumbling then it's likely to be a spark problem.

 

[82Shafty]

ok will check it and repost, thanks for help griffin i wann get this thing fixed by sunday cause i wann take it to the drags which is about 50 miles or so away i want it to make it.

Post up some vids or links to vids !

 

[Kbecker3]

i had a problem similar to that last summer. mine ended up being the vacuum hose was getting kinked and must of collapsed when i was hitting the gas (just a guess?) but i ened up putting one of those springs like on bike bandit if you look there is a spring that goes over the fuel line to keep it from kinking, i placed one of those over the vacuum hose and never had a problem again. not sure if your problem could be like mine, but it worked for me.

 

[kurt12345]

well i went for a ride today went to work its about 15 miles not a problem, on the way back home right when i got off the exit it cut out, it sounds like 2 cyclinders are running i didnt have time to check the coils had to take off, but thanks for all your guys hints, i dont think i can take a video with my camera dont know how to mount it, well anyways i got a good starting point more stuff to try tommarow

 

[B Evil]

I've had very similliar problems with my 550. Keep us posted on what you find out in case I have the same problems after the valve adjustment, carb rebuild, and petcock replacement.

 

[Junkie]

I had some issues with a cylinder cutting out, turned out the wire was falling off the coil. I put it back on better and it's been doing fine since then.

As far as what's causing it goes, see if you can find out which cylinders are cutting out. If it's either the center two or the outer two, it's much more likely to be a coil than if it's a different set.

 

[Dark Jedi]

longshot, but what they hey.

I had surging/power issues on my bike. Someone here said the drain lines on the carbs were too long, causing the wind to change the carb vacuum values.

I thought they were bananas, but I trimmed them and tucked them behind the engine and out of the wind... and the problem went away.

Perhaps you are having a similar issue?