85' 550L Must wait to re-start after running, needs a lot of choke or gas to idle

[Guest]

1985 Suzuki GS550L - Everything is original factory. Ok, so this is my first bike and I've ironed out a lot of issues so far but this one is being a pain. It's a beautiful bike, and I paid way too much for it I'm told, but I loved the timeless curves and style so I've dumped money into it and keep working at it. (parts are so damn difficult to find!![and pricey] uhggg)

Here is the problem/s that eludes me:

Seems to run just fine going down the road. It seems to lack power but if I combine choke and gas it makes a big difference. Usually on first attempt I can start the bike just fine in short time like 3 revolutions. It always rolls good but often it won't fire up after its been running (drilled small hole in gas cap for vapor lock already) and it won't idle properly unless give it either a little choke or gas (adjustment screw increased on throttle cable will keep it running). If I accidentally let it die in traffic it's very embarrassing (so I just feed it more gas to avoid it), as I have had to push it off the road because it won't let me restart it right away. I can either wait like 30 minutes or I can manually clutch start it by coasting down a slope (which it takes right off every time). It's also burning rich and using a lot of fuel.. I should be getting like 60mpg but I start with full tank, ride about 70 miles, then I have about a quarter tank left maybe. Takes about 9 bucks or so to fill it up. (Further proof is when idling the exhaust really smells of gas.)

I clearly have a small air leak at the intake manifold (carb boot on engine side) since I sprayed them with carb cleaner and engine revved up. New or even used in good condition are hard to find and very expensive. Airbox boots seem fine.

Any ideas? So far my research has told me either the vacuum leak and/or jets (but those have been cleaned). This problem has been annoying the **** out of me, makes me wish I would have saved my money, and for about 3 grand I could have had a 2005 model bike or even newer. I'm ashamed to admit I have about 1700 or more in this thing now.

Some but not all misc things I've done since I got it:

Carbs have been taken apart and cleaned. Used tiny wire on idle jet hole and sprayed with carb cleaner etc. Float bowls looked pretty clean.

Installed in-line fuel filter.

Installed new correct air filter.

Changed oil and filter.

I've rebuilt the starter and it rolls the engine great.

New battery and voltages are correct across the board. Stator is keeping it charged just fine. Was having electrical problems but sorted them out, was a grounding issue.

I know basically an engine needs air, fuel, and spark to run but there is more to it than that.

[almarconi]

I'd get rid of the inline fuel filter and see if it runs better without it. If your bike has o-rings under the intake boots, these should be replaces since they are probably dried out and hard. Check the voltage at coils, it should be near battery voltage when you turn on the key. If you have more than 1 volt drop, consider the coil relay mod so that your coils are getting full battery voltage. When you put the carburetors back together did you check the float height? Did you replace o-rings in the carburetors? There are many issues that could be causing your problem.

[tkent02]

I know basically an engine needs air, fuel, and spark to run but there is more to it than that.

There is. It needs to have compression. An adequate spark at the right time. The valves need to open and close at the right time. It needs to have the valves adjusted correctly. It needs the right amount of fuel. Not sure why you are running rich, but fix everything before you try to ride it much. Your boots are wasted if it revs up with carb cleaner, replace them all with new ones. The airbox boots too. They do cost a little money but not as much as a new motorcycle, and not as much as fixing the engine after burning it up due to air leaks or tight valves.
Have you done much of the required maintenance on Cliff's list?

http://members.dslextreme.com/users/bikecliff/

And welcome to the GSR.

[mike_of_bbg]

You need to check your coil voltages. Whenever I see, "hard to start with starter but can bump-start just fine", that's my first suspect. Weak spark, probably some carbon fouling of the plugs. Coil relay mod might be in order. While running the starter your voltages will drop, and if you're already running a little low at the coils it's going to get worse (which is why bump starting seems to work much better since you don't have the additional drain).

Clean or replace plugs.

Check voltages at coil feeds.

Check impedance of coil primaries and secondaries.

Check impedances of all plug caps.

Sounds like you're really facing probably multiple issues since your carbs don't seem to be right either.

[Steve]

I do believe that a carb cleaning is in your immediate future.


Some adjustments will have to be made for your "slightly oddball" carbs, but the principle is the same.

.

[Juriah]

Thanks for the suggestions guys.. I've not been able to find any new intake (engine side) boots or O rings for them either.. everything out there seems to be for the larger 800ish bikes of the time. Ok so I lied, here is a set for 130 bucks..I'm a full time student, not a walking bank lol, this stuff is getting expensive. I thought bikes were cheaper than cars lol. I'll try to check these voltages at coils and such like you say. A family friend has worked on bikes for 25 years or more and he has been trying to help me as well. I already paid him 300 bucks to do some work which is definitely way cheaper than a shop... I don't mind doing it myself but I'm impatient and up to my eyeballs in school work. I let myself be taken like a fool when I purchased this bike.. the guy didn't disclose the buttload of work this bike required. I should have walked away when he had a hard time starting it but I'm compulsive.

[Juriah]

next step

Next thing I'm going to do, which I should have done already, is replace the plugs. Could solve a lot of my problems my family friend says. He does agree with the replacing the boots, he said 130 bucks for a pair of new ones ain't bad at all.

[Steve]

Ok so I lied, here is a set for 130 bucks..I'm a full time student, not a walking bank lol, this stuff is getting expensive.

You can't trust eBay any more than you can the previous owner.

Click HERE to see brand new ones, from a Suzuki dealer, for $40 each.

You will need to get new o-rings, but I think you can get them from cycleorings.com. I know he has them for other bikes, not sure about yours with the siamesed carbs.

Most of the other hardware can probably be re-used, but you should get the stainless bolts from cycleorings as well.

[tkent02]

I thought bikes were cheaper than cars lol.

Not even tiny little econobikes.

[JEEPRUSTY]

If your carbs are clean
Check your valves

then move on from there

no shortcuts

Carb boot and carb O-Rings are available from Cycleorings.com

These also need changeout.


Do these things and come back with the results.

[850 Combat]

I do believe that a carb cleaning is in your immediate future.


Some adjustments will have to be made for your "slightly oddball" carbs, but the principle is the same.

.

No kidding

[Juriah]

thanks

Thanks guys for the tips and references to sites to get this stuff. I'm replacing the plugs now, and they looked normal according to THIS.

I'm cleaning off the ground contacts at the coils now to ensure a good connection there. Intake manifold/boots/o-rings on the way.

Btw the carbs have been cleaned, needles/jets good and cleared, float levels good, had a friend of my stepdad's there who has been working on bikes 30 years there helping me do it. I was paying him at a discounted rate.. the bike had a more serious problem before where it wouldn't even roll over.. it turned out a grounding issue at the ignition module or something. I'm pretty much on my own now physically but I feel like I have plenty of help here to get me through it. Thanks a lot. =)

[Juriah]

new plugs

Does anyone know the exact gap specification for this bike so I know for the record, I looked around quite extensively for a list? Ok, so anyway I replaced plugs with D9EA as factory calls for, and gap to 19 thou (closest to 15 thou I could get, I saw somewhere someone said proper gap was 13-15 thou) and it's starting every time and idles much better... but of course consuming a lot of fuel... I have new intake manifolds and o rings here for it and will put them on soon, see how much it helps the rich fuel problem... and yeah, these damn oddball carbs, lucky me. I'll let you know after the new manifold n boots are on. (I'm wondering if someone changed the needles or something or bored the orifices out to make it rich for "more power")

[Juriah]

Rebuilt the carbs myself, clean as a whistle... put new boots on and intake manifold... didn't solve my problem however.. now to check out other suggestions

[Juriah]

I'm fed up!

I didn't do valve clearance check yet I just don't have time. I did the coil relay mod.. was starting and running great, plenty of power because of new intake manifold.. rode it about 130 miles or so.. then all of a sudden it's acting like its not getting gas... when I was going up a hill in particular.. no leaks.. somebody said maybe a filter inside tank at petcock.. who the fk know.. spark plugs looked perfect condition.. just a hair white but mostly light brown..I'm done with this pos for the year.. its ate up way too much of my free time and money could be spent on my school homework/work/girlfriend