Engine Won't start

[dfinnegan71]

I picked up a project 1980 GS550 recently for$100 bucks. T
It was complete all there, as far as I could tell. It had no spark and the gas had been left in it since 1995. Anyway, I got spark back in all 4 cylinders, completely cleaned out the carbs and replaced a gasket or two. The tank is a disaster and is soaking in vinegar as we speak. I have a fresh battery hooked up and it turns over real strong, but won't start . It kinda sputters like it wants to start but just won't. What am I missing here? Got spark, clean carbs, air flow....

[tom203]

make sure you got spark plug wires on right. 17 years is a long time,so it will take some affectionate maintenance to get it happy again.
Meanwhile, click on this link and go to first post

http://www.thegsresources.com/_forum/showthread.php?t=183245&page=2

[dfinnegan71]

wires

can you give me an idea how they go? Mine aren't numbered. I think it should be 1&4 on the left (from riding position perspecive) coil and 2&3 on the right coil, right? Anyone have a diagram?

[cowboyup3371]

Yes, the left coil is supposed to feed 1 and 4 and the right 2 and 3. Have you looked over your wiring diagram and compared it to what's actually on the bike to make sure everything is right?

If not, download it from Basscliff's site as you'll need it later.

[dfinnegan71]

still perplexed

I have good spark now, cleaned the crap out of my carbs, read all I could on Bikecliffs site (or is it Basscliff?) I'm gona get a rash of sheeeeet for saying this but..... I put a few drops of gas in each cylinder and hit the start button. The ol' girl puurrrred back to life for a couple of seconds. But only long enough to burn those few drops of gas I put in there.
This tells me the carbs aren't creating the vacuum needed to pull gas out the float bowls, does that sound right?
I should also say, I didn't have the tank on, because I just derusted it with vinegar and the sealer is still drying. I had my make shift fuel cup attached to the intake line to the carbs feeding fuel into the float bowls.
I should also add that I decided to take the carbs off again after this attempt and soak them in carb dip this time. Apon taking them off I realized I hadn't tightened the carbs to the header, just stuffed 'em in there. I left all 4 tightener things loose. Would that create my loss of vacuum?

[Seana23]

Hi babes.
Yes, it would loose a little vacume without the inlet rubber clips on...
Did you also make sure that all the float bowls properly filled as sometimes the outer 2 are a bit slow...
Undo the drain screws on the float bowls and put ya hand over the carb mouths to suck fuel through really quickly.
Then do up the drain screws and try again..its worth remembering that the fuel is sucked into the carbs so the tempory vessel your using cant be airtight as a vacume bubble will form stopping the fuel flow...
Did you renew the spark plugs?

Good luck
Xxx

[dfinnegan71]

I drained the bowls and they were all full. I didn't replace the spark plugs but I will. Thx.

[dfinnegan71]

The only thing left to deal with is air flow. I have a new air filter on the way. I mean I have spark, compression and a clean set of carbs. the only thing left is air flow. The original filter in this here project bike is all chewed up by who knows what and god only knows how old. Sound like the right idea?

[matt1100]

Not trying to be a jerk but, when you say you thoroughly cleaned the carbs you do mean that you disassembled and dipped them...right?

[dfinnegan71]

Your not being a jerk at all. I appreciate your input. Yes, I disassembled and dipped with NAPA carb dip. I just ordered up two new piolt jets because #2 and #3 jets were stripped and I couldn't get them out. I thought the dip would be enough, but apon further discussion with folks, it probably wasn't. I can tell you #1 and #4 piolt jets were gunked up really bad. everything was, the bike sat since 1995. The tank was totally covered with rust, the petcock was clogged up and the crap in the float bowls was down right nasty. But it all cleaned up real well. So we shall see.
The piolt jets are what gets the fuel flowing while cranking it over, right?

[Mekanix]

You got it!

It's a well known "newbie" thing that we see allot around here for just giving the carbs a quick spray with carb cleaner and asking why it doesn't work


You can be sure that you have found the main reason why its not even close to running on its own.

Once your finished with them, you can install them and maybe start the bike but these carbs are jetted for a restrictive airbox. So you might not get anything at all when your done if you don't have the airbox on.

If you don't have the filter yet then you could zip tie some shop rags over the back of the carbs and that's usually enough to get it to start and have a slight bit of throttle response.

Putting gas in the cylinders to see if it will run is something I would have done. At least then you know. But all in moderation of course

The next thing you want to look at is the valves, After its running and run-in a bit your probably going to find some tight valves that need shim replaced and maybe some loose ones.

Carbs, shims, air leaks, airbox, coil voltage, charging system, grounds and wiring, are all things you should look into as anyone here will tell you.

[dfinnegan71]

Thanks for the input. I put the air box on, the new air filter is on. I did try the gas in the cylinders and it sit and sputtered for a few seconds. Hopefully the new piolt jets will do the trick. Any other ideas?

[mpencegs]

Check the valves immediately. Mine was in exactly the same boat as yours.. Sat for 26 years instead though. I did not check the valves until they were already a bit bent.. Save some grief and start there.. Then Carbs, Carbs Oring, Air boots, Air boot Orings.. Also if the old jets are stock attempt to clean and save them. Better materials then after market and some of the afters are not correct anyway.

[dfinnegan71]

Valves? Oh boy getting in deep, but hey I got this thing for $100! Might as well give it a shot. Any tutorials out there on how to adjust these valves?

[mpencegs]

Everything you need is on this site. http://members.dslextreme.com/users/bikecliff/

Crtl+f for valve
:-)