Breaking up while accelerating

[80GS750]

Hello fellow GS riders. New to the site here. I have a issue when I accelerate. It seems as though it breaks up. I have added fresh fuel, cleaned the plugs, and added some fuel additive (gumout carb cleaner). It just recently started. A friend of mine had a similar issue with his 2010 Honda Fury saying it was his rev limiter. Does the 80 GS 750E have one or is this another issue? Thanks in advance for any advice.

 

[Guest]

We need a lot more info to help diagnose the issue.

Throttle position? RPM range? Stock airbox or pod filters? Stock exhaust or aftermarket 4-1? Have you cleaned the carbs and checked valve clearances? How do your ignition wires look? Plug caps OK? Can you better describe the problem? Does it run rough but continue to accelerate or does it run into a wall it simply won't pull through? Does rolling off slightly improve the problem?


Mark

 

[garagepunkfan]

too much information left out....you need to do some detective work

did the carbs sit with fuel in them for any extended period of time? adding some kind of product to the fuel will do little or nothing to combat the varnish and residues left behind when fuel is left in carbs from improper storage

if they have, have you disassembled, soaked them in Berrymans for 24 hours minimum, reassembled properly with new o-rings, bench synched first to start the bike and final synched running with carb sticks or similar unit?

when you did all of this, did you check the condition of your intake boots? if they are hard, they wont seal, creating a vacuum leak and making it impossible for your CV carbs to operate correctly. same if they are cracked. buy new ones from Suzuki

your plug wires...how about the condition? search the threads for replacing the epoxied-in plug wires on the coils and replacing the boots with NGK boots

check coil voltages with a multi-meter. if you are reading anything less than 12v you need to do some searches here for voltage drops and the coil relay mod

 

[80GS750]

Throttle position is when I am starting to accelerate, at idle it is fine. Airbox is stock, exhaust is stock though it does have an exhaust leak after the cross bar. Spark plug wires look good, plug caps are snug when attached. It seems as though it breaks up when given fuel to accelerate. Once I get up to speed, it seems as though at doesn't break up as much. I have not cleaned out the carbs yet. It has not been sitting for any extent of time. I noticed it breaking up last friday when riding into work. Before that, it only sits anywhere between 2-3 days at the most before being used again

We need a lot more info to help diagnose the issue.

Throttle position? RPM range? Stock airbox or pod filters? Stock exhaust or aftermarket 4-1? Have you cleaned the carbs and checked valve clearances? How do your ignition wires look? Plug caps OK? Can you better describe the problem? Does it run rough but continue to accelerate or does it run into a wall it simply won't pull through? Does rolling off slightly improve the problem?


Mark

 

[Guest]

Throttle position is when I am starting to accelerate, at idle it is fine.

What I mean by throttle position is how open the throttle is. Carb circuits are determined by throttle opening so we need to know more than "starting to accelerate". Does that mean 1/2 throttle, 3/4, full throttle, what? Does rolling off a bit when it is stumbling improve things? A simple test to see if it is jetting is to pull the choke a bit as you get into the problem area. If it gets better you are lean, if it gets worse or stays the same you are rich.


Mark

 

[Crankthat]

Most likely jets with gunk in them.
Do you notice it more while throttling out of a high lean turn?

Could be a air leak in the system.
Boots from motor to carbs, carbs to airbox or the big one from airbox to filterhousing misaligned, not clamped tight, not installed into airbox correctley, clamps at angle or otherwise not tightened well.

The airbox could be warped causing air to leak past the boots and turbulence in the flow.

You may have a plug wire sparking on the case or frame.

Might be something else.

My first guess would be carbs with gunk or air leak though.

Everything else I would look at while you are adjusting your valves and cleaning the carbs the proper way.
Trust me and everybody else on this site as it is a must do.

By the way, welcome to the site!

Let me introduce you to BaseCliffs website where you will find much reading and need to do walkthroughs.
BaseCliff is a member here but has been busy with other things lately but would give you a huge welcome if that was not the case.
Copied And Pasted, Be sure to go through the links, BaseCliffs site has much info for your 16 valve GS 750.


07-10-2012, 02:22 AM #1
BassCliff

Senior Member Past Bard Award Winner
GSResource Superstar
Super Site Supporter


Join DateMar 2007LocationSo. Cal.Posts18,484


[h=2]

New Members, CLICK HERE!![/h]

Greetings and Salutations,

(EDIT: Please DO NOT "Reply" to this thread to introduce yourself. This is an informational post only. Feel free to start a new thread in the "GS Owners" section of the forum to introduce yourself. Thanks!)

Every once in a while I will miss a new member or two and they may not receive their proper greeting. If you are here you probably have a 30 year old motorcycle that needs about 20 years worth of maintenance. In the links below you'll find maintenance lists, documentation, wiring diagrams, "how to" guides, vendor links, tips, tricks, and a whole lot of GS goodness. This is your "mega-welcome". Let's get started.

Let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...

Please Click Here For Your Mega-Welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

More links to helpful threads in the forum:
Help! Your Bike Won't Start
DON'T DO THESE THINGS
Help! Your Bike Won't Run Well
Oh God! Pods!


Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff​

Last edited by BassCliff; 05-15-2013 at 05:58 PM.​

A popularity contest is not a truth contest. I strive to speak the truth, not become popular.
Click to meet Jessie Blue>> GS850GT
(Progressive springs, MDI shocks, Goodridge stainless steel brake lines, Tarozzi fork brace, "L" exhaust, Slipstreamer Spitfire S-06 windshield, Bridgestone Spitfire S-11 tires)
*****Click here to read about Jessie's crash and restoration*****
Visit the BikeCliff Website for pictorial maintenance guides, tips & manuals.
John 3:16 Would you like prayer? Send email to GSR Prayer Group.




​

 

[Guest]

Your bike does not have a rev limiter, your wrist is your rev limiter. Sounds like you have some work ahead of you. What maintenance has been done to the bike recently? I assume what you mean by breaking up is a bad sputter right? How long have you had the bike? Has it been sitting for awhile?

 

[80GS750]

I did some more troubleshooting. I replaced all spark plugs. The #2 cylinder doesn't seem to be firing. It has spark however the exhaust is cooler than the others. When opening the drain for the carb bowls, no fuel poured out. I switch the petcock to and will try running it on reserve instead of on. Any other suggestions?

 

[Rob S.]

Most likely jets with gunk in them.
Do you notice it more while throttling out of a high lean turn?

Could be a air leak in the system.
Boots from motor to carbs, carbs to airbox or the big one from airbox to filterhousing misaligned, not clamped tight, not installed into airbox correctley, clamps at angle or otherwise not tightened well.

The airbox could be warped causing air to leak past the boots and turbulence in the flow.

You may have a plug wire sparking on the case or frame.

Might be something else.

My first guess would be carbs with gunk or air leak though.

Everything else I would look at while you are adjusting your valves and cleaning the carbs the proper way.
Trust me and everybody else on this site as it is a must do.

By the way, welcome to the site!

Let me introduce you to BaseCliffs website where you will find much reading and need to do walkthroughs.
BaseCliff is a member here but has been busy with other things lately but would give you a huge welcome if that was not the case.
Copied And Pasted, Be sure to go through the links, BaseCliffs site has much info for your 16 valve GS 750.


07-10-2012, 02:22 AM #1
BassCliff

Senior Member Past Bard Award Winner
GSResource Superstar
Super Site Supporter


Join DateMar 2007LocationSo. Cal.Posts18,484

New Members, CLICK HERE!!

Greetings and Salutations,

(EDIT: Please DO NOT "Reply" to this thread to introduce yourself. This is an informational post only. Feel free to start a new thread in the "GS Owners" section of the forum to introduce yourself. Thanks!)

Every once in a while I will miss a new member or two and they may not receive their proper greeting. If you are here you probably have a 30 year old motorcycle that needs about 20 years worth of maintenance. In the links below you'll find maintenance lists, documentation, wiring diagrams, "how to" guides, vendor links, tips, tricks, and a whole lot of GS goodness. This is your "mega-welcome". Let's get started.

Let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...

Please Click Here For Your Mega-Welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

More links to helpful threads in the forum:
Help! Your Bike Won't Start
DON'T DO THESE THINGS
Help! Your Bike Won't Run Well
Oh God! Pods!


Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff​

Last edited by BassCliff; 05-15-2013 at 05:58 PM.​

A popularity contest is not a truth contest. I strive to speak the truth, not become popular.
Click to meet Jessie Blue>> GS850GT
(Progressive springs, MDI shocks, Goodridge stainless steel brake lines, Tarozzi fork brace, "L" exhaust, Slipstreamer Spitfire S-06 windshield, Bridgestone Spitfire S-11 tires)
*****Click here to read about Jessie's crash and restoration*****
Visit the BikeCliff Website for pictorial maintenance guides, tips & manuals.
John 3:16 Would you like prayer? Send email to GSR Prayer Group.




​

I almost thought 'Guff' was back (the 'ransom note' fonts).

 

[rwnielsen]

Leave the drain screw out and put the petcock on prime. See if fuel drips out. A couple gentle whacks with a plastic hammer might unstick a float that's hanging up.

 

[chuck hahn]

Do ALL the maintenance and rebuild the carbs per the CV carb tutorial here. Get it ALL..I repeat this..ALL done and sync the carbs. Until and unless YOU PERSONALLY can verify that its ALL done, youre chasing ghosts. Bet once yu do ALL the required maintenace your problem will vanish.



http://www.mtsac.edu/~cliff/storage/gs/mc_maint/GS_CV_Carb_Cleaning_Series.pdf

 

[80GS750]

Here is the latest, I took the carbs off, cleaned them completely out including jets and floats, added new spark plugs, confirmed spark, carburetor gets fuel in bowls, and when I try to start it and i get it to sputter and thats it, I let it sit overnight and checked it tonight, When I stood it up, i noticed fuel leaking, after further investigation, i see when I take the points cover off, it is leaking fuel from there, at first it was a steady stream and now it it is dripping. When I tried starting it, no change to the flow of fuel coming out. I was supposed to go on a planned ride tomorrow but repairing this takes more proirity, now i have 2 bikes down. PLEASE HELP !!!

 

[Spyderman]

if you take the oil filler cap off and you can smell gas then you have a few problems
1 fuel tank petcock is not functioning as it should allowing fuel to flow even if the bike is not running or it is leaking fuel down the vacuum hose to the carb
2 float height is incorrect or the float needles are sticking
3 if you have fuel coming out the points cover it is either leaking down the engine to there or you have alot of fuel in the crankcase and the crank seal behind
the points is leaking
in either case of #3 don't run the bike till you either change the oil and stop the fuel leak and confirm the crank seal is not leaking because if you have fuel in the points area it is not good as it can lead to a fire

so it looks like your going to rebuild or replace the petcock and your going to tear down the carbs again and properly clean and confirm all settings are correct then change the oil to be sure that there is no fuel in the oil as it will thin it out and you will do bad things to the engine in a real hurry
good luck and let us know how you get on with this

 

[80GS750]

Status update. Gas was mixed in with the oil in the crank case and leaking from the crank case seal where the ignitor is. I changed the oil with a new filter and filled to the correct level as well as install new spark plugs Bike started right up. When I swapped cylinder 2 & 3 sparkplug cables, the problem followed the cable. When I put the cables back into the correct locations, 2&3 exhaust pipes remain cool compared to 1&4. I read voltage of 9.5 going to coil one and no reading going to coil 2. I forget what the wires colors coming from the plug where the coil plugs into but I tried to trace them out and couldn't find their source. Any ideas or does it sound like the bad coil 2 which feeds cylinder 2&3 shorted out 3 cylinder as well?

 

[rwnielsen]

When you go back and edit previous posts it makes it really tough to follow... Just sayin'...

 

[60ratrod]

if you aren't getting 12vdc switched hot at the 2/3 coil(orange/white wire), then you have a short in that wire somewhere. if you are talking about the signal wire that comes from the ignitor, you shouldn't be seeing much voltage coming from that wire when the bike isn't running. but getting 9.5 at the other coil isn't a good thing either. you probably have some corroded connections in there somewhere, or you might be looking at having to do the relay mod, which really does a good job at getting full juice to the coils. go to bassclif's site and get a schematic for your 550 and start looking at where your connections are.

 

[Spyderman]

if you aren't getting 12vdc switched hot at the 2/3 coil(orange/white wire), then you have a short in that wire somewhere. if you are talking about the signal wire that comes from the ignitor, you shouldn't be seeing much voltage coming from that wire when the bike isn't running. but getting 9.5 at the other coil isn't a good thing either. you probably have some corroded connections in there somewhere, or you might be looking at having to do the relay mod, which really does a good job at getting full juice to the coils. go to bassclif's site and get a schematic for your 550 and start looking at where your connections are.

^^^^^^^^good advice here^^^^^^^^^

so it would seem to me that you have more than 1 culprit to your problem
1st you need to fix the coil issue
2nd you need to fix the gas leaking into your crankcase
for the 1st follow the above advice

for the 2nd take the carbs apart again and confirm the needle and seat are working and the spring in the needle is still strong and that all the floats are at the same level (indication of a weak spring in the needle) then confirm correct float height and that the plugs are there for the pilot jets once done with the carbs rebuild the petcock (and there is a chance it may not work if it doesn't then replace it with one that does factory or after market) and you should then no longer have an issue with gas in the crankcase

 

[80GS750]

Any suggestions? I am new to the forums but find it really helpful

 

[RGM]

Could be a simple as a bad condenser. If you don't have a voltmeter that can measure that then see if the points look burnt. When running with the points cover off see if the points are sparking. do it in a dim lit garage or a night works best. You don't want to see them sparking. Or just put in new condensers and see how it runs

 

[Spyderman]

Any suggestions? I am new to the forums but find it really helpful

well welcome to the site
i think you need to read post 17 again i have told you what you need to do to fix the issues you have

also go here as this is the best GS info site there is all the how to's you need are there on that site
http://members.dslextreme.com/users/bikecliff/