wont start

[raider]

I have an 82 gs550L that I bought a few months ago. It did not run when I bought it. I have replaced the spark plugs, battery, starter relay, cleaned the carbs several times, replaced the intake pipes that go from the carbs to the motor because the rubbers were completely detached from the flanges, did a compression test(120psi), and still it will not start. It cranks and cranks good and strong, and after trying for a bit I pull the plugs and they are bone dry. They should be wet. So my thought is that Im not getting gas to the motor because of vacuum. everything looks tight to me. The pilot jets are CLEAN. I have pulled the carbs apart several times. It will turn over on carb cleaner. I have rigged up a funnel on the end of the gas line as a gas tank because the one that came on the bike was rusted out. This has officially gone above my pay grade. Any thoughts?

 

[Steve]

I have ... cleaned the carbs several times, ...

Any thoughts?

Just one. Clean the carbs. Properly. Once.

Sorry to sound crude, but too many people say they "clean the carbs", even "several times", when all they do is spray whatever they can see with liberal amounts of spray cleaner. This is not enough, as you will see in the link to the carb cleaning series above. The proper way is to totally dismantle the carbs and dip them (individually), probably overnight, in Berryman's Carb Cleaner Dip, which should be available at better auto parts stores in your area. Get the gallon-can size with the parts basket, cost is about $25. Since you will need to take the carb apart completely, you will need new o-rings when you put them back together. You can get them at Cycle O-rings. The owner there is a member of this forum and has put together a good product at a price that simply can't be beat. You say you have already replaced the intake tubes. Did you also replace the o-rings that seal them to the cylinder head? If not, you can get new ones from Cycle O-rings.

By the way, what is your area? You can edit your location and other details by clicking on the "User CP" link in the upper-left corner of the forum window. If you add your bike information to your signature, we will be able to see what you ride and where you are without you having to remember to add it to every question.



Just one more thought ...

 

[Suzuki mad]

Start at the begining.

You've checked the compression. You've checked the engine is timed correctly. You've checked that its firing correctly. You've check that fuel is getting to the float bowls. You've checked the spark plug and found no fuel.

Does sound like you still have blocked jets in the carbs. Have you followed the carb procedure as per the letter? If not then thats likely why she won't run. Sorry.

Suzuki mad.

 

[BassCliff]

Greetings and Salutations!

Greetings and Salutations!

Hi Mr. raider,

Please click here to receive your mega-welcome, chock full of recommendations, suggestions, tips, and an extensive online vendor list. Then feel free to visit my little BikeCliff website for lots of GS lovin' (manuals, illustrated maintenance guides, etc). Thanks for joining us.


Thank you for your indulgence,

BassCliff

 

[tomo]

Hi Raider. Before doing any work on the carbs, try first turning the petcock to prime for about 30 seconds then turn back to the normal position, then put on full choke and try to start her up. If that fails, try blowing into each of the two carb breather pipes a couple of times. Pull on the choke again and try the starter. Some of the other guys are probably thinking "oh! not again" as I`ve posted this tip a few times, but its helped get a lot of bikes going too !. My GS 750`s won`t start without a "blow job" if they`ve been stood a while. Worth a try !.

 

[Suzuki mad]

To blow or not to blow.... that is the question

To blow or not to blow.... that is the question

Hi Raider. Before doing any work on the carbs, try first turning the petcock to prime for about 30 seconds then turn back to the normal position, then put on full choke and try to start her up. If that fails, try blowing into each of the two carb breather pipes a couple of times. Pull on the choke again and try the starter. Some of the other guys are probably thinking "oh! not again" as I`ve posted this tip a few times, but its helped get a lot of bikes going too !. My GS 750`s won`t start without a "blow job" if they`ve been stood a while. Worth a try !.

Had to 'suck' my GS1000 when I first got it. No fuel coming down the pipes even on prime. Turned out to be a faulty fuel tap.

Suzuki mad

 

[raider]

I have followed that carb cleaning series almost fully. The only thing I did not do is take the carbs off the bank and dip them. I pulled all of the tops of the carbs, slides, float bowls, floats, jets, needle valves, etc. and cleaned everything. When I first got the bike the needle valves were stuck open, so the fuel would pour out of the breathers. so I got everything moving freely on those, reset the float heights. It stopped overflowing and now the float bowls hold fuel. As for priming the carbs, I have pulled the original tank off because it was rusted through. I have a sportster tank Im going to put on once I get it running. Right now I have a funnel hooked up to the gas line as a small temporary tank just to try and get it going. I would think that having the funnel on it would do the same thing as putting the petcock on prime because I have no vacuum operated petcock, just a straight line into the float bowls like an on or off petcock. I know for sure there is no obstructions from the float bowl through the pilot jet circuit. I have cleaned all four pilot jets, the tube they are in, the crossover from the main jet and the main jet.

 

[Guest]

I have followed that carb cleaning series almost fully. The only thing I did not do is take the carbs off the bank and dip them.

If you didn't dip 'em, them they ain't clean. Everything else you do will be an exercise in futility...

As Steve said before, "... Clean the carbs. Properly. Once."

Mike

 

[raider]

Its ALIVE!!!!!!!! I tried blowing through the breather pipes and as soon as I hit the start button she roared to life!!!! Now I can start rebuilding. Thanks a lot guys. Much appreciated.

 

[BassCliff]

Hi Mr. raider,

If you're going to put off cleaning the carbs, at least use some Sea Foam in the gas to give your carbs a fighting chance.

Thank you for your indulgence,

BassCliff

 

[tomo]

That breather pipe trick has nearly always worked for me. First shown it by an old biker buddy many years ago after I rebuilt my 750. The bike still will not start without it, but has always run great once its going. Several thorough carb strip & cleans since have made no difference, so I just accept it now as part of my starting procedure if the bikes been stood a couple of times. Had to get used to a bit of p..s taking at rallies, but have surprised a lot of people by getting their bikes going after they`ve spent ages cranking em over and checking electrics, carbs etc.

 

[Matchless]

That breather pipe trick has nearly always worked for me. First shown it by an old biker buddy many years ago after I rebuilt my 750. The bike still will not start without it, but has always run great once its going. Several thorough carb strip & cleans since have made no difference, so I just accept it now as part of my starting procedure if the bikes been stood a couple of times. Had to get used to a bit of p..s taking at rallies, but have surprised a lot of people by getting their bikes going after they`ve spent ages cranking em over and checking electrics, carbs etc.

Now the million dollar question - why? What happens when one blows into the breathers? Does it mean the floats are sticking or the float level is out? Could there be an air bubble trapped somewhere? Does this happen simultaneously to all 4 carbs? there must be a logical explanation. Anyone?:-k

 

[raider]

So this is something I may have to do all the time? I would like to figure out the anwser to this milion dollar question. Hopefully I dont have to.

 

[tomo]

Don`t know why it works, my best guess is that it force primes the carbs. It`s worked on my old CX500 and a mate`s CB750 too. Although I`ve had the carbs stripped and cleaned as best as I could, I`ve still had to blow start the bike !. However, I did`nt know about "cycle O rings" at that time, maybe replacing all the rubber parts may help ?. But at the end of the day, the bike starts first time this way and runs well, which is what counts.

 

[Matchless]

Don`t know why it works, my best guess is that it force primes the carbs. It`s worked on my old CX500 and a mate`s CB750 too. Although I`ve had the carbs stripped and cleaned as best as I could, I`ve still had to blow start the bike !. However, I did`nt know about "cycle O rings" at that time, maybe replacing all the rubber parts may help ?. But at the end of the day, the bike starts first time this way and runs well, which is what counts.

Please don't get me wrong on this. If that remedy is works on various bikes it must point to something wrong in the carbs and seeing Mr Suzuki did not design them to work that way it would be very interesting to know what is causing it and will also help solve many similar issues.
Just a question - Do those bikes have an inline fuel filter fitted? :-k

 

[tomo]

Hi Matchless, no offence taken, I quite agree that there must be something amiss. I guess I`m a bit old school in that provided the bike runs well I leave things alone. I`ve just got so used to having to blow into the tubes its become part of the starting procedure !. Only required if the bikes been stood a few days though. But to answer your question, one of my GS750`s, the chop, has an in line filter but the other bike is stock. The CX is stock too, no in line filter either.

 

[rustybronco]

My opinion.

A likely scenario...
You would be pressurizing the fuel in the bowls when blowing air in the vent tubes,
force feeding fuel into the intake system.

with the choke circuit not properly working, ether by plugged passages in the fuel bowls or, in the transfer tube in the main body, you would get no "extra" fuel for cold enrichment.
with the added presurization of blowing into the vent tubes, extra fuel would go to up the main jet past the needle in the needle jet and also some additional fuel through the "pilot" circuit: allowing the engine to start.

when the engine has started, you have the negative pressure of the engine vacuum drawing up fuel as normal: keeping the engine running.

not enough information to properly diagnose at this time.

whatever the reason for blowing into the vent tubes, a problem still remains with the carbs.

 

[tomo]

Hi Rustybronco. I agree blowing into the tubes forces a bit of fuel through, but when I had the carbs stripped a few years back I know all the passageways were clear, used carb cleaner, guitar string & compressed air. Still needed to blow into tubes to start it after the bike had been off road a few days. I agree something is not right, but its not what I`d call a problem, the bike starts and runs well and at the end of the day thats all I want. I have wondered whether it may be connected with something else. All my bikes are high mileage, don`t know about the others the trick has worked for. Wonder if compression is a bit down, whether air is`nt sucked through the carbs enough when the engine is cold to "pull" the fuel into the stream. I guess once its fired the air is getting pulled in a lot quicker. Can`t remember what the readings were last compression check, I remember they were less than spec but not by too much. Think I`ll check all the bikes compression this week-end out of interest. Could be barking up the wrong tree, but I guess it sounds like a possible reason they need "blowing" after a few days off the road. What do you reckon ?.

 

[Matchless]

My opinion.

A likely scenario...
You would be pressurizing the fuel in the bowls when blowing air in the vent tubes,
force feeding fuel into the intake system.

with the choke circuit not properly working, ether by plugged passages in the fuel bowls or, in the transfer tube in the main body, you would get no "extra" fuel for cold enrichment.
with the added presurization of blowing into the vent tubes, extra fuel would go to up the main jet past the needle in the needle jet and also some additional fuel through the "pilot" circuit: allowing the engine to start.

when the engine has started, you have the negative pressure of the engine vacuum drawing up fuel as normal: keeping the engine running.

not enough information to properly diagnose at this time.

whatever the reason for blowing into the vent tubes, a problem still remains with the carbs.

rustybronco,
You are making a lot of sense here. The symptom is then like trying to start the bike without the choke (OK, this is a starting enrichment device and does not reduce the air, but provides a very rich fuel/air mix for starting via its own passage) Thus if the starter jet is not passing fuel into the starter circuit, it could be due to blockage, starter circuit not opening or not reaching the fuel level in the float bowl, then the choke would not work.:-k

tomo,
Do you think your choke is working properly? Maybe its not opening fully or blocked. On my bike if you goose the throttle with the choke out it becomes hard to start, the throttle must be left closed when the choke is out. When cold it definitely will not start without the choke and with full choke with throttle closed it takes on the first or second swing of the starter, then climbs to 3000 rpm and I then gradually push the choke back and the rpm's settle at 1100 after about 30 to 60 seconds. When warm even after a few hours it still does not need choke.

My apologies for asking this as this solution actually intrigues me quite a bit.

 

[rustybronco]

My apologies for asking this as this solution actually intrigues me quite a bit.

The only way to know the answer would be to take apart the carbs on a bike with the problem.
plugged/partially plugged passage(s) in the choke circuit would be my guess.

It is my opinion that the carb bowls are more often, not cleaned well enough and tested for proper flow through the very small passage in it.

which would make the proper cleaning of the rest of the choke circuit, about useless.