Thoughts - 1983 GS550E Stalls When Stopping

[MacGyver]

Just for giggles, put the petcock on PRIME and go for a run. See if it makes ANY difference to anything. (Don't forget to set it back to RUN after!)

I had year-long driveability issues (including stalling upon stop) that I was going nuts trying to track down. That simple change cured all. (BTW, new petcock is on order...)

Yes, that was one of the first easy to check things I learned about here and tried right away. The petcock seems to be fine as the flow is quite good on prime (into another tank) and in every other aspect the engine runs fine. The bike loves to zip along the road, but does not like to slow down or stop. I can't say I blame it, but it can be inconvenient, especially for a beginner rider like my girlfriend.

[Roger P.]

My 1983 550E always died under heavy braking as well. I wonder if it's a design quirk of those dual barrel carbs they came with? Did a lot of high speed running through Alberta back in the mid 90's on my 550E, including one memorable run out the highway to Drayton Valley where I saw an indicated 210kmh. My petcock was suspect as well, as the engine would often starve for fuel when running flat out for any length of time.

[MacGyver]

My 1983 550E always died under heavy braking as well. I wonder if it's a design quirk of those dual barrel carbs they came with? Did a lot of high speed running through Alberta back in the mid 90's on my 550E, including one memorable run out the highway to Drayton Valley where I saw an indicated 210kmh. My petcock was suspect as well, as the engine would often starve for fuel when running flat out for any length of time.

Hi Roger,

Looks like we traded locals. I grew up on the St. Lawrence river just South of Ottawa - take Bank Street South until you get to the St. Lawrence and stop. I moved out to Calgary in the fall of 1997.

I am now confident that the issue lies in the carburetors and very likely is related to the twined design amplifying the problem. What ever is blocking a pathway or what adjustment is required, the end result is affecting two cylinders. Combine that with perhaps a float design and mounting angle in the bike that causes problems when all the inertia is sloshing everything forward and there is your 'quirk'. As I mentioned earlier in this thread, I had a friend help me check, quick clean, and balance the carbs, but at that time there were a few too many other issues affecting our efforts. I feel I have taken care of everything now except for the carb rebuild. The engine runs great at speed, there seems to be no issues with the main jets. The idle is now somewhat stabilized, there was obviously an intake leak and the wrong plugs with their larger gap likely didn't help. Hopefully the valve adjustment cured the lazy compression on #2.

It has been a great experience so far and perhaps the best part of it is in all my work I have only made thing better on the bike. The confidence and understanding this process has given me has been very valuable. If my KLR ever gives me grief out in the middle of no-where, I'll have the confidence to deal with it.

Say g'day to the Ottawa Valley for me and go to Hull - oh wait, they don't call it that anymore.

[Calvin Blackmore]

Hi Roger,

Looks like we traded locals. I grew up on the St. Lawrence river just South of Ottawa - take Bank Street South until you get to the St. Lawrence and stop. I moved out to Calgary in the fall of 1997.

I am now confident that the issue lies in the carburetors and very likely is related to the twined design amplifying the problem. What ever is blocking a pathway or what adjustment is required, the end result is affecting two cylinders. Combine that with perhaps a float design and mounting angle in the bike that causes problems when all the inertia is sloshing everything forward and there is your 'quirk'. As I mentioned earlier in this thread, I had a friend help me check, quick clean, and balance the carbs, but at that time there were a few too many other issues affecting our efforts. I feel I have taken care of everything now except for the carb rebuild. The engine runs great at speed, there seems to be no issues with the main jets. The idle is now somewhat stabilized, there was obviously an intake leak and the wrong plugs with their larger gap likely didn't help. Hopefully the valve adjustment cured the lazy compression on #2.

It has been a great experience so far and perhaps the best part of it is in all my work I have only made thing better on the bike. The confidence and understanding this process has given me has been very valuable. If my KLR ever gives me grief out in the middle of no-where, I'll have the confidence to deal with it.

Say g'day to the Ottawa Valley for me and go to Hull - oh wait, they don't call it that anymore.

Gosh I was in Hull once....it was cloudy and drunk adn all the women were naked....it was the oddest thing.

You have doen a really nice write up on the progression of your efforts
thus far.

I wonder if it may be realted to a dramatic drop in vacuum upon deceleration causing the carbs to basicall stop flowing fuel.

One wonders if decelerating in 1st rapidly as opposed to pulling int the clutch from any higher gear would produce a different result.

[Larry D]

Naked women and beer ?........(ala Hank Jr.)

Where is this Hull place again ?!?!?!

Gosh I was in Hull once....it was cloudy and drunk adn all the women were naked....it was the oddest thing.

You have doen a really nice write up on the progression of your efforts
thus far.

I wonder if it may be realted to a dramatic drop in vacuum upon deceleration causing the carbs to basicall stop flowing fuel.

One wonders if decelerating in 1st rapidly as opposed to pulling int the clutch from any higher gear would produce a different result.

[Calvin Blackmore]

Naked women and beer ?........(ala Hank Jr.)

Where is this Hull place again ?!?!?!

Hullis in the province of Quebec just across form Ottawa Ontario.....
Maybe it all got amalgamated into a metro Ottawa area er something..

This brings to mind what soneobne told me once and likely stole forn another source...

"if God doesn't destroy Hull he's gonna owe Sodoam and Gomorrah an apology"

amazing the trade in flesh that surrounds a city filled with politicians and diplomats etc...oh and for a few days me.....

[mostholycerebus]

Still having similar problems here now. I replaced the intake O-Rings, rubber tubes from airbox to carbs, intake boots, rebuilt the carbs, and did the R/R mod. What happens is it starts GREAT and runs fine. I can ride it all over, but when I run it it dies on the road when i let off the gas and the RPMs drop. All i have to do though is hit the start button while rolling though and give it gas, starts right up and goes.

BTW the R/R duneage sends is not the right size for these bikes either. No prob though, i just got a 'joiner' bracket from Ace hardware and bolted that in, fits fine now.

[twiggy2cents]

i dont think they bolt on on any of them with out minor modification i think at least

[GSJim69]

Could be that there is some rust or something in the tank. You mentioned that there was some crud in the float bowls. I was having issues with my bike and discovered that rust from the tank was causing the problem. I installed an inline filter until I have a chance to properly clean up and coat the tank.

[MacGyver]

Still having similar problems here now. I replaced the intake O-Rings, rubber tubes from airbox to carbs, intake boots, rebuilt the carbs, and did the R/R mod. What happens is it starts GREAT and runs fine. I can ride it all over, but when I run it it dies on the road when i let off the gas and the RPMs drop. All i have to do though is hit the start button while rolling though and give it gas, starts right up and goes.

BTW the R/R duneage sends is not the right size for these bikes either. No prob though, i just got a 'joiner' bracket from Ace hardware and bolted that in, fits fine now.

G'day Cerebus,

That has happened to me a few times as well, but not so much after zip-tying the intake boots. The idle is pretty stable once the engine warms up. A quick tug on the front brake and the engine dies. Even just pushing the bike along and stopping it will kill the engine so any aggressive braking and you need to ride the throttle.

Once I get carb #1 cleaned up and the air mixture preset screws behaving as they should I will know I am on the right track. Currently carb #2 behaves and the screws seem to be happiest about 2.5 turns out which is what many others have reported. No one seems to be sure what the factory setting was.

I am pretty sure the previous owner replace the stator and R/R with an ElectroSport part. Foolishly he mounted the R/R upside down and the seat was rubbing and pressing against the wires. That was easy enough to fix and there was no permanent damage. Discovering the shorted stator wire and correcting that took a couple of drained batteries later.

I am getting close, I can feel it. Now I am just waiting for USPS/Canada Post to deliver me CycleOrings! Posts will follow. This time I'll be working on the carburetors with a much more educated eye paying critical attention to all the idle related parts.

[MacGyver]

Could be that there is some rust or something in the tank. You mentioned that there was some crud in the float bowls. I was having issues with my bike and discovered that rust from the tank was causing the problem. I installed an inline filter until I have a chance to properly clean up and coat the tank.

Yes, I will have a very keen eye out for that and other issues when I have the carbs apart this second time.

I have learned so much these past few weeks, a testament to the great people here and the shared knowledge. I hope that my voyage of discovery will help someone else now or in the future.

[mostholycerebus]

That has happened to me a few times as well, but not so much after zip-tying the intake boots. The idle is pretty stable once the engine warms up. A quick tug on the front brake and the engine dies. Even just pushing the bike along and stopping it will kill the engine so any aggressive braking and you need to ride the throttle.

Thanks for the info. Mine isn't as bad as your sounds, but i think I may need to better seal where the airbox meets the intake tubes. They have steel clamps on them now, but i'm not sure how well that is sealing.

[MacGyver]

Carb rebuild in progress...

I took the carbs out this weekend, the CycleoRings.com package arrived in the mail on Friday, what a way to ruin a weekend.

Because I noticed the plug when I was working, I pulled the airbox hose drain plug and was greeted with a dirty mix of what seemed to be mostly gas. Hmmm, gas is leaking somewhere, this is a problem I could see traces of it in the airbox next to carb #1. I removed the carbs and there seems to be more gas in the floats and in and around the carbs in general than their should be, this is a problem. Well I guess that is what I am doing all this work for after all, I am having problems.

Other observations when pulling the carbs apart:

One of the diaphragm assemblies was rotated 180 degrees on one carb. The diaphragm should have a tab in about the 7-8 o'clock position (toward the rear left side of bike) and the hooks should be open toward the back of the bike. I cannot be sure if this made any difference, but it could mean that upon braking, the inertia forces the slides forwards and they could stop moving temporarily affecting the CV nature of the carb and potentially the fuel air mixture.

There was a lot of gunk of all sorts in the fuel tubes and float valves. This is likely the reason there was gas all over the place, the floats were overflowing. I'll have to check the needle valves once they come out of the dip, they appeared OK to the naked eye, but felt a bit rough. I hope they don't have to be replaced as that is an expensive item, $40 on BikeBandit.

The hardest part of this was managing the dip. It is very powerful stuff - it started eating away at my nitrile gloves. It also makes the parts very slippery and couple of times the parts splashed in my bucket after they slipped from my grip. What is the best way to get this stuff off the carb when cleaning is done, there are no instructions about that on the bottle?

I'll try and locate some clear fuel line hose so I can keep an eye on how much gunk is flowing out of the tank. If I can find an appropriate fuel filter, I may slap one of those in there as well. The tank does have a few rust spots in it and I think it would be wise to agitate and drain the tank to try and get rid of any sediment that may cause future problems.

[Nooner]

For what it's worth, I paid $800US for a 550T with 4,00 miles on it last year. I have had some stalling while at idle, but not much. Took some GS forum advise and used seafoam carb cleaner, it seems to have worked well. I also heartily recommend the stator papers, they were a big help to me. My IQ usually drops 20 points when I pick up a wrench.

[MacGyver]

I used Seafoam when I picked up the bike. When a friend helped introduce me to carburetor tuning we took a quick look at the jets and such and found that most of the working parts/jets were pretty clean. Whether that was from the Seafoam or simply somewhat regular use by the previous owner, I don't know.

Yes, the stator pages are great and fairly quickly helped me determine that there was a short in my stator lines which I located and fixed. No electrical issues now and proper spark plugs have been installed.

The carbs are back together now and everything is very clean. The fuel tubes were quite dirty and had a lot of varnish build up. The filter at the needle valve had done a good job of catching much of the dirt. The needle valves have a bit of wear on them and probably should be replaced, we will see how they perform now that everything else is cleaned out. I hope that Carb #1 will behave itself with respect to the pilot air screw adjustment now.

I drained the gas tank through a plastic hose with a simple in-line fuel filter attached. There were no traces of any sediment or dirt. Once empty I removed the petcock and found negligible amounts of dirt. The filter on the petcock is very fine, finer than the in-line filter I used.

So I have a clean fuel delivery system. New air filter for a clean air delivery system. New intake o-rings and zip-ties until I can locate some replacement clamps. Valves have been adjusted. If this doesn't cure the stalling issue, I don't know what else can be done without spending a lot of excessive money. I fear it will turn into a 550 twin carb curse/quirk.

Tonight it goes back together and the truth will be known.