20 Most Recent 1979 Suzuki GS 400 E Questions & Answers

First be sure your battery is full charge (12.6 volts). Check the fuses. Then you will find the starter solenoid under the seat just behind the battery. With a voltmeter check for voltage coming in from the little wire on the third post when the motor is in neutral, the key is on, the clutch is pulled in, and the start button is pushed. You are dealing with a very old bike. No matter how well maintained the wires in the switch housings are old and brittle. Its best just to leave them alone unless you are good at soldering very small things. If the start button isn't working bypass it with a hidden button on the frame or under the seat.

your shorting .. make a good visual check first looking for corrosion or suspect wires..then if need to, unplug much of the circuit only leaving enough to turn the engine, then if still goes then you have narrowed down to that circuit. then bypass start switch by crossing starter relay, if that ok you know wires to switch the prob.. plug back 1 thing at time and check... hope this helps

Try shorting out the 2 10mm nuts on the starter relay (has the lead from the battery and starter going to it) if the the engine turns over chech the relay or safety switches. It will flash so make sure the is no open fuel. If nothing happens try tapping the starter motor l(lightly) then try it. If this works the brushes in the starter are worn out..Dont keep on doing it as you will burn the comutator in the starter..Brushes are cheap.

hi , i would say this should be fine, however if you are worried you could use a fuel addative, you may also ask yourself how long they have been using unleaded fuel in Japan, regular servicing, with a keen eye on valve clearences is probably the best way to go, hope this helps, paul

you have 3 potentials issues. 1. the start button is sticking 2. the starter solenoid is going bad 3. the ignition relay is shot. its located on the foot brake side of the quad behind the plastic vover by the upper part of the frame. i would most likely says it is your button though. try taking a open and wrench and jumping it right at the starter solenoid to see if it still does it. if so this rules out the starter solenoid

to replace that seal you do not have to overhaul the motor. but you have to drain the coolent and place the motor up side down and open the crank case and pull the stator of as well as the internal coil pack. the internal coils and stator must be off befor you can open the crank case. replace that seal and get black form a gaskit and put her back thogeather and you should be good to go

call a tech at a dealer and he will look it up--some mc salvage yards have info too

I have a set my float to 22.0 +- 1.0 for a Mikuni carb.
To set floats, drain the carbs, pull the carbs from the bike invert and remove float bowl.
With the carb inverted, take off the float bowls. Take off the gasket. Use a vernier caliper or an accurate device to measure from the carb body to the top of the float block.
Here is are a couple of good sites about carbs and such.
http://www.allthingsmoto.com/forums/f-15/how-set-your-motorcycle-carburetor-float-level-more-commentary-13608/
http://www.dansmc.com/carbs2.htm

if it has gas and spark then the valve timing is the next thing to check.

Try a this sight, it is called manuals online

IT PROBALY HAS POJNTS ON THE R/S OF THE ENGINE IN THE MAGNETO OR CHARGER. PLEASE RATE MY RESPONSE

Does other GN of GS mudguards don't fit? Must be... Change it to 12 volt, that would be handy... I don't know, ask a Suzuki store…

Low charged battery ,Bad battery, bad ground or loose terminal bolt

You may have a vacuum leak. Your carbs may just need be adjusted and synced. I would not be surprised if the carbs have been out of sync since day one.

You have a clogged fuel filter...change it!

Chances are strong the bike has a bent shift fork. This is a major repair requiring a complete engine tear down. As far as the leak goes, there is a shift shaft seal, drive-shaft ( sprocket shaft ) seal, Kick shaft seal. shift drum switch seal, crank shaft seals and clutch shaft seal. Also, there is the right outer case cover gasket, oil filler "O" ring seal, and the center case mating surface seal. The center case seal is actually a semi-liquid gasket compound applied to the mating surfaces prior to the center case re-assembly. The shift fork repair is not recommended for the unexperienced home mechanic. Below are the main parts if a Suzuki shift mechanism and a diagram of how the shift forks move left and right to change gears. Please rate my answer. Thanks!

There are of course many possibilities as to what the noise could be. It is troubling that a mechanic listening to it could not make a better diagnoses other than piston slap. Early Suzuki four strokes often had some piston slap probably due to larger tolerances. This sound generally will go away or lesson as the pistons get warm and expand. With out being able to hear the noise , my best guess is pre-ignition. Start by doing a compression check, both cylinders should be over 110 PSI and with in PSI of each other. If compression checks out, install new spark plugs and more importantly new NGK spark plug caps (about $5 each). Next take off the carburetors, inspect the intake manifolds for cracks or separation (air leaks), clean remove the carburetor tops and inspect the vacuum diaphragms if damaged or pin holed replace them (about $152 each)(a used set may give you the needed parts for less), thoroughly clean and reinstall the carburetors. If the problem was just a lean condition on one cylinder this may bring the cycle back to its original glory. If the damage is deeper in the motor (crank) perhaps a donor cycle or engine would be the best option. Unfortunately, the only way most of these options will work is if you are willing to put in the sweat equity your self to save the labor rate.

The fuel petcock for your gas tank has a vacuum bladder in it. If there's no engine vacuum, fuel is supposed to stop flowing out of the tank, preventing carb overflow and accidental draining of the tank. However, once the engine starts, fresh gasoline will begin to flow out of the tank into the carbs. I believe but am not certain anymore that the vacuum cutoff mechanism is disabled when you turn your fuel petcock to "prime" or "reserve." If that is correct, you should be able to duplicate the carb overflow with the petcock in one of these positions.

As for the specific cause, it sounds like one or both of your carb floats may be sticking in position, preventing the fuel shut-off needle from seating correctly. This can easily happen if you haven't ridden the bike for a while--the most volatile compounds in the gas in your carbs will evaporate, leaving behind an increasingly gummy and sticky substance that will eventually harden into varnish if it's not cleaned out. That gummy stuff seizes up the pivot points for the carb floats, so they don't move correctly. Gummy gasoline residue can also build up over time, even if you ride the bike often, though this usually happens after the bike has been sitting. The fix for this is to clean out your carbs. On an early (1982) GS450, I was able to do this once by removing the carb bowl without removing the carbs from the motorcycle and spraying the float pivot points with a heavy-duty gum cutter (Berkebile 2+2--it's like carb cleaner on steroids, but it will also damage paint).

By the way, if I remember correctly, your carbs have a crossover tube to ensure that both carbs have the same gasoline level in them. This keeps the fuel mixture even for both cylinders and keeps the engine running smoothly. However, that also means that a single carb with a stuck float will flood both carbs equally.

The bike should be upright to check the oil level

you wont feel the resistance, as the 5 or 6 springs are stronger than you will be able to push. you can probably pull it out easily, and push it back in until it feels solid, this sound fairly normal.
wait for the new cable and see how it goes.
sometimes the clutch plates can stick together if it sits for an extended time, if you roll start it and vary the throttle while holding the clutch in, it usually unfreezes them.