GS750T stalls when coming to a stop ?

[MR2dieFOR]

Hi, first post (yay),
Unfortunately my first post has to be related to a problem I've been having the past week.

Back Story:
My 1982 GS750T sat with some fuel stabilizer in the tank since last October. The previous owner installed 4 pod filters (yikes) and an aftermarket exhaust. The oil pan gasket is slightly seeping but nothing to really notice. Decided this July to take it out and start using it. Popped the battery from last season in (which was brand new and was on a tender since October 2014), replaced the spark plugs/gapped correctly (previous ones were black and smelt of fuel, possibly oil), and performed an oil change with new oil filter. Rode to the nearest gas station after warming her up and filled. Put 15 miles on it that day just to ease it in. It was okay for being freshly out of "storage", but still ran.

Current:
After sitting for a day or two, I rode it with more excitement, but all of a sudden when I'm up around 3rd-5th gear and then coming to a full stop, the RPMs just drop all the way down to where it stalls (clutch in). I have to rev it up to keep the bike alive or else it'll completely die out. Once it dies though I'm still able to be crank it back up but with slightly more throttle.

I'm thinking it's a carb issue, possible float bowl issue, or clutch adjustment?

If you guys have any questions I can answer to help me/us narrow this down, I'll be more than helpful.

Thanks guys!
Jeff

 

[GSXR7ED]

One time, my "T" revved up randomly and I found the throttle cable was getting stuck on the engine. So make sure there is nothing keeping the throttle from retracting.

At least that's one trouble shooting action you can cross off the list.


Ed

 

[gustovh]

You might try checking your gas cap vent, but you probably need a carb cleaning.

V

 

[JTGS850GL]

Carbs probably need cleaning but check your valve adjustments as well.

 

[tom203]

"Once it dies though I'm still able to be crank it back up but with slightly more throttle"

this says carb cleaning is needed - the slow speed circuits are restricted. When you put fuel treatment in last fall, did you run bike a bit so the stuff could circulate into carb passages?

 

[MR2dieFOR]

Absolutely, I ran the bike for about 5-10 minutes to make sure it cycled through, BUT I do remember I accidently left it in PRI for a bit, I switched it to on/res, but now I'm thinking the bottom of my float bowls have varnished. I'm guessing i'll have to remove the carbs and scrub that section down. Would you guys recommend me taking apart the carbs or just hitting everything internally with brake cleaner and some string for the jets?

 

[eil]

Absolutely, I ran the bike for about 5-10 minutes to make sure it cycled through, BUT I do remember I accidently left it in PRI for a bit, I switched it to on/res, but now I'm thinking the bottom of my float bowls have varnished. I'm guessing i'll have to remove the carbs and scrub that section down. Would you guys recommend me taking apart the carbs or just hitting everything internally with brake cleaner and some string for the jets?

A full teardown is highly recommended. Click the link in my signature for the mega-welcome and follow it down the rabbit-hole. Eventually, you'll get to BikeCliff's (a.k.a BassCliff's) web site which contains very details carb rebuild tutorials.

It may not fix the issue, but the process of elimination is the core of troubleshooting things like this.

Do not use brake cleaner for anything.

Welcome!

 

[tom203]

Next time you use stabilizer, best to add it to tank (I double dose it) ,then take bike for ride >20 minutes to be sure it it has found those itsy bitsy tiny carb passages to hibernate in.
String?? It's hard to push on a string! You're probably best to do full monty carb dip - this will let you see what previous owner did with jetting when he made the leap to podland. Don't assume that he did it right, cuz bad things happen if this thing runs too lean for too long.

have you seen this stuff?

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

 

[MR2dieFOR]

So update: just ripped apart the carbs, jets, diaphragm. .. it's all spotless, zero varnish, I can see the moon through my jets, what gives? Bad fuel? I'm checking over spark tomorrow, I have a feeling my plugs are coated over with oil.

 

[tom203]

" I can see the moon through my jets, "

that's good, but can you see thru all those passages that make up idle circuit? -once plugged, you got idle problems

 

[MR2dieFOR]

I shot some cleaner from all ports and jets, shot myself in the eye a couple times lol. But it seems to flow pretty smoothly.

 

[MR2dieFOR]

Okay so update:
Put the carbs back on and installed everything. Still acting up so I rechecked the spark plugs and they're extremely black (I'm guessing I'm running to rich).

But now there's something else ; I can't seem to start the bike without push-starting it. It's like one second it worked and the next something seems like it blew. It could be a number of things, the bike does not want to go into neutral when it's off, does not start with clutch in/side stand up, the killswitch is on run but starter button does nothing.

Once I get the bike moving and powered up I have to rev it a bit and then find neutral to eventually get it to idle by itself, but once the bike dies I'm stuck having to push-start and such all over again.

Neutral switch, side stand sensor, clutch too tight, or starter button? I don't know.

Thanks guys,
Jeff

 

[tom203]

When you saw the moon thru your main jets, did you note their size? Maybe PO overcompensated for pods (or got creative and drilled them!) and you are running rich.
The no start /push start stuff with button is an electrical problem -have you done a sanity check on your charging system to see how it is? Do a Quick test and report all 6 results. Note that you need to start with fully charged battery

http://www.thegsresources.com/_foru...System-QUICK-TEST/page2&p=1272192#post1272192

 

[MR2dieFOR]

Wow, probably shouldn't have worked on or rode it at night in this condition. I found the red tagged cable, coming from the negative terminal on the battery that goes to the right side of the engine, was loose and disconnected entirely. Anyone know what that is, I'm assuming it's the starter on the right side of the engine?

 

[Spyder]

You should stop asking questions if you are not going to listen to the answers. You have been given expert advise and have done none of it to fix your issues.

A good old start would be to update your location. Perhaps there is one of us in your area that would be willing to get together with you to help you resolve these problems you are having.

It it sounds to me that you are running really rich on the idle circuit. That is usually a simple adjustment of the mixture screws. If you would answer some of the important questions that have been asked we can help you get that machine running perfect.

 

[tkent02]

You should stop asking questions if you are not going to listen to the answers. You have been given expert advise and have done none of it to fix your issues.

Very comical, very true. He probably knows more about these old bikes than the rest of us put together.

 

[MR2dieFOR]

In no offense, I've been trying to follow the expert responses but everytime I'm about to do something you guys have recommended, something else comes up, hence the random updates and questions. I can't exactly follow through with your recommendations if something else comes up.

A poster said do a "sanity" check and check over the electrical system, as I was about to do that, instead I found that red tagged cable, I mentioned early, going to the right side of the engine from the battery terminal, which I was assuming a starter if not neutral switch. After repairing that wiring issue the bike is now able to start through the button again and displays neutral.

Now i can check the mixture screw.

So I do apologize if I haven't gone with everything you guys have noted but I had other issues in the way.
When the carbs were apart the jets were knicked up on the outside so I couldn't get the numbers, looks like they compensated with larger jets by way too many steps.

 

[tom203]

Yes, you need a functioning electrical system . But until you open up those carbs to know what PO did, you are flying blind regarding the stalling and black plug issues. Running with pods can be tricky, cheap pods are probably useless - many are forced to get a dynojet kit to get a decent midrange.