Cant Keep 1982 Suzuki GS450GA Running

[DerveyZ]

Hello Everyone Jared back here again, Im having issues with getting my bike to stay on, Heres a video on what I mean https://youtu.be/eb4BbC29lPg

Any help would be greatly appreciated! I want to get this bike on the rode before it get too cold here in Ohio to ride! Thank you!


-Jared

[Rich82GS750TZ]

See top 10 Newbie mistakes thread. Carbs likely need cleaned. See BikeCliffs Website for your type of carb (CV). Stop twisting the throttle when starting. That’s what the enriching circuit (choke) is for. Prime the carbs for half a minute only if they’re empty. Put petcock back to On or reserve. Zip tie some rags over the carb mouths if you don’t have proper filtration yet. If everything is clean and sparking and compression is good, should start and run. Once running, may have to adjust the idle speed knob between the carbs to settle to a proper idle after warm. Gradually reduce choke as it warms. Sounds easy, right. But there’s a lot going on here.

[DerveyZ]

Thank you Rich, Ill check that post out, carbs were cleaned about 4 months ago, hopefully it just needs to run for a bit and get the oil pumping through it, was sitting for a few years I believe from the PO

[rphillips]

Yep, what he said, no pumping the throttle, it ain't an old "66" Chevy. These carbs take no throttle to start & run. Must have "some" restriction in the intake side of the carbs. If idle adjust knob is set too low or too high, it won't start. May try turn the idle adjust knob in 1/2 turn increments, both directions & try it with no throttle, trying to find the sweet spot. Sorry, I don't have a clue how many turns in or out should be close initial setting...

[Buffalo Bill]

Nobody could start a GS using your method…

[DerveyZ]

Thanks guys. I appreciate the honesty Buffalo bill, I’m just a newbie, trying to find my way, I haven’t messed with the idle knob yet so I will definitely look more into that, I appreciate the advice!

[Who Dat?]

Don't want to beat a dead horse, but everybody so far has been VERY correct.
1. CLEAN the carbs PROPERLY. Strip and dip them, then rebuild with a cycleorings.com o-ring kit.
2. Prime the carbs, but this only has to be done when the carbs are dry.
3. Use the "choke". Start with full "choke", then back off to adjust speed. Eventually you will find the sweet spot (usually about 1/2) where it will start the best.
4. DON'T EVEN TOUCH THE THROTTLE. Although your bike does have an accelerator pump, it won't pump enough to do what you think you are doing by pumping the throttle. By the way, the 450GA is the ONLY GS that I know of that has an accelerator pump.

[Buffalo Bill]

Post #2 Rich82GS750TZ gives you all the info anybody can at this point.

[rphillips]

VERY INTERESTING!!! This is always a learning place, I never knew any GS's had an accelerator pump. Some old Kawasaki's did, but never "remember" seeing it on a GS. Thanks Dat...or Who, for the info.

[OJKD]

Mine is just the same. It's in three million pieces right now to fix it, but it seems like we have a fairly similar starting point.

I am sure I could have just done some simple measurements to verify that the coils are good, put new plugs in, cleaned and serviced the carbs to get it running, but I am not planning on riding it this year anyway. Just do it right, and you are going to do alright. You should probably do a compression test to rule it out.

[Who Dat?]

VERY INTERESTING!!! This is always a learning place, I never knew any GS's had an accelerator pump. Some old Kawasaki's did, but never "remember" seeing it on a GS. Thanks Dat...or Who, for the info.

Yep, I have also seen them on the other three (Kawasaki, Yamaha, Honda), but the only GS I have seen with a pump was the 450GA.

Something else for your trivia bank: did you note the "GA"? Yep, that little semi-automatic bike has a shaft.

[dkratz5]

I'm having a similar problem with my 1982 GS450GA. I found a small hole in my accelerator pump diaphragm and now that I messed with it a bit fuel leads out the boot where the pin comes out of the carb body. Any ideas where I could get a new diaphragm? It's discontinued...

Huge thanks for the advice of no throttle for starting. That works much better.

The bike starts fine and then sometimes throttles up fine and then the next time sounds just like the bike in the video at the top of the thread... no power. Thoughts?

[tom203]

”I'm having a similar problem with my 1982 GS450GA. I found a small hole in my accelerator pump diaphragm and now that I messed with it a bit fuel leads out the boot where the pin comes out of the carb body. Any ideas where I could get a new diaphragm? It's discontinued... “

probably impossible to find! I’d probably remove the diaphragm, block up / seal the opening and see if accelerates better and you stop leaking gas…maybe try a richer mixture screw position. Starting should be no different as this gizmo ain’t used at startup.

[dkratz5]

tom203 Blocking off the accelerator pump worked for stopping the fuel leak in the carb but it didn't change the issue I'm having with running/acceleration. It sounds very similar to DerveyZ orginal post on this thread https://youtu.be/eb4BbC29lPg

I'm able to start it fairly easily. Then, one moment it's idling fine and then the next moment it's dying out. I can give throttle to keep it from stalling but it won't accelerate up until something happens internally and then suddenly it seems to be running fine again. Similarly, when I ride down the street, one time it pulls away perfectly fine and then the next time it will lose all power and won't be able to pull away at all and doesn't want to keep running. Strange...

I'm starting to think it is something outside of the carburetor but don't know where to look next... maybe electrical? Like it's firing fine one moment and then the next moment not? Any thoughts?

[dkratz5]

Well, I tested the spark by putting a tester in line after the coil and going to the spark plugs. Both sides jumped an 8mm gap so they seem good. Not sure what to do next... any thoughts?