Top 20 1979 Suzuki GS 750 E Questions & Answers

CHECK THE POWER TO THE COIL, AND FROM THE COIL TO THE SPARK PLUG; TAKE ONE OUT LAY IT ON THE BLOCK CONNECTED TO THE WIRE, NOW CRANK THE ENGINE AND LOOK FOR A SPARK. NO SPARK NO POWER. CHANGE THE COIL.

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Check the fuse box first then use a multi meter to check for earth and power feeds to the lamps.I would start with the rear one first

You will likely have to rejet the carburetors due to the more open intake

There are 2 coils. The coil on the left provides spark for cylinders 1 & 4. The coil on the right provides spark for cylinders 2 & 3. The firing order is 1-2-4-3. In case you don't know, this little tidbit is something to carry with you for life: Whenever a reference is made to a place in or on a vehicle, it is ALWAYS the perspective "from-left-to-right" of the seated vehicle operator. In other words, in your case, as you're sitting on the bike, cylinder #1 is the one furthest to your left, and #4 is furthest to your right.

Not exactly sure what you mean by "number" but i purchased two new ignition coils and my 1978 gs750 runs like its fresh from the factory. here is the link where i purchased them. http://www.regulatorrectifier.com/catalog/1977-1978-Suzuki-GS750-GS-750-Ignition-Coil

Hi I had the same problem with my gs it was valve clearance they were to tight

more than likely one of the coils died or plug wire insulation is rotten and it's arcing to the frame, be sure to check all wiring connections before you buy anything.

I suspect it is a very similar set up to my 81. It would probably be much easier if you remove the carburetors, (Something I've had to do MANY times, haha) but I have gotten mine out with them on. There is a metal plate on top of the lower end engine block, behind the cylinder block. Take the bolts out of the plate and remove it. You will see the starter, with a couple of bolts in it. Take them out and remove the starter.

Yes, you need to replace the accelerator fuel pump assembly located on the carb. bracket and connected to the mechanical linkage next to one of the carbs. If that does not fix the problem try replacing the carburator bowl gasket's. That might do the trick!Good luck my friend,kd4ruaP.S. You can obtain a rebuild kit for the accelerator pump assembly from www.cyclepartsnation for a reasonable price.

you dont say whether you have pressure at the lever, ie the lever is stiff to pull, if yes then suspect the master cylinder is seized and needs overhaul or better still replacement, if you have no pressure then you either have air in the system or the master cylinder seals have failed this is again overhaul or replacement.

buy a bottle of sea foam and add to gas that should clean the varnish out well i use it about every 1500 miles

What do you consider a "horrible sound" and where is it coming from?
Does the front wheel spin freely, no binding, no bearing problems, no fender rub, etc.? Does the bike coast ok, with the clutch in and out and in all gears? Are the front calipers working ok and not sticking?

Not all carburetors are identical - the manufacturing processes create minute differences in the size and shape of the fuel lines inside the body of the carbs. The older the bike, the more imprecise the manufacturing and bigger the internal differences.
In your case the carbs with the malformed regulator needles were made over the tolerable manufacturing limits and to avoid scrapping them they had to modify the needles to keep the mixture uniform. When you replaced the modified needles the air intake to the fuel and mix jet was reduced, the fuel consumption went up and the mixture became rich in those cylinders. So you ended up with a much higher fuel intake for essentially the same power output from the engine.
You have 4 options:
1 - you put back the original needles;
2 - you keep the new needles but you modify the setup of those carbs - you lower the level in the bowk and you readjust all the jets;
3 - you remanufacture the entire carb to standard specs;
4 - you replace those carbs with good ones.

Yeah, you gotta lube the cable sometimes. It's important, 'cause if the cable hangs up the clutch may not throw in fully.

PbBlaster will probably work well, Tri-flow brand oil is good for cables. WD-40 will help work out water if there is any in there, follow it with a lubricant such as I mention above.

lp

It shouldn't be no more than 200 to 350 dollars if a small engine repair shop does it......Hope this helps.

here in canada leaded fuel is not available, and i have never experienced any engine damage done with unleaded, there was talk of valve damage possible but it was unfounded, even the calssics have not experienced any damage, so feel safe

The simple answer is no. It is possible to put a complete 1000 engine into the 750. but this will involve making brackets etc.
Proberbly the easiest way to more power is to fit the barrells and top end from the GS850. This will fit straight on. Ideally, you will need the 850's carb, but the 750s could be jetted to suit. The exhaust is the same fittings, so you could retain the gs750 exhaust as well. They also share the same airbox.

CHECK THAT YOU HAVE PROPER FLOAT HEIGHT AND THAT THE NEEDLE VALVE IS NOT STICKING. I HAD A SIMULAR PROBLEM ON MY 1979 GS850 ALL I DID WAS TAKE OFF FLOAT BOWL AND ADJUST FLOAT HEIGHT A LITTLE AND CLEANED NEEDLE OFF SEEMS TO HAVE WORKED NO GAS ON OUTSIDE OF CARBS NOW

The simple way is put a volt meter acoss the battery, should read 12v engine stopped and about 13.5 with the engine running. Make sure the battery is in good condition and charged first.
if there is no voltage rise it may be the regulator, but the problem could also be the stator.
They should have three wires of the same color going to the regulator(white or yellow) any pair of these wires will produce ac voltage when the bike runs, about 50v, and none of these wires should have continuity to earth.