Need some advice for 77 gs550 owner.

[johnhend]

Dyna S already installed? BONUS!

Yes, on my GS550 left feeds 1 and 4 and right feeds 2 and 3. More importantly, with a Dyna S the 1 and 4 coil should be grounded with the WHITE wire and the 2/3 coil the BLACK wire (from the 3-wire Dyna harness). The RED 12V feed for the Dyna can come off of either coil (the orange/white wire) or any other constant 12V source, it doesn't matter.

Don't charge the battery with more than 2A current. Use your voltmeter to ensure your orange/white coil wires are getting ~12V with the ignition on. If they're not the coil relay mod may help, if they already are don't bother. Instead of the coil relay mod, you could have a field day cleaning connectors, particularly around the ignition switch. That's usually where the voltage loss is.

Any idea how the right two cylinder were able to run with the ignition wires reversed like that?

Also, could the left to cylinders not start because of bad initial timing of the dyna s?

[mike_of_bbg]

With the Dyna, whichever coil has the white ground is the one that runs cylinders 1 & 4. Position doesn't really matter so long as the wires reach. The PO might have gotten the grounds confused. Definitely check the wiring.

If the initial timing was that far off, 3 and 4 should have never run, either. The same module fires 1 and 4, and the other fires 2 and 3. If 3 is in time to run, then 2 should be too. It would be a good idea to borrow an inductive timing light and verify the timing from 1000 to 2500 RPM - though that requires a running bike. There's also a static timing procedure. You can go here:

http://www.dynaonline.com/skins/downloads/Default.aspx

select "Dyna S" from the drop-down, and get the installation instructions for the DS3-1 or DS3-2 to find that procedure. You probably also want to look at this helpful tidbit from Mr. Bwringer (lower pic):

http://www.bwringer.com/gs/tdc.html

[johnhend]

I checked the wiring from the dyna s. The only potential problem that i can see is they splice the white and black dyna grounds and the red 12v wires going toward/into the ignition switch. So the dyna runs through the ignition switch and then back down to the coils. I measured the voltage on the charged battery and it read 13.4 volts. I measured the orange/white and ground going into the coils and I got 10.4. After reconnecting a bad connection, I got 11.35 at the coils.

Still no start. I can get it to pop and back fire with the choke on and petcock on prime but no start. It seems like I've got bad coils. Not sure what a really strong spark should look like though.

[mike_of_bbg]

Splicing the Dyna wires in is pretty normal. With the points gone the other end of the wire goes to nothing.

A strong spark should be "fat" and blue. Weak spark would be thin and probably orange. I know that "fat" and "thin" are a bit subjective... Take your plugs out (are they wet w/fuel?), hook the wires back up, and lay the threads of the plugs against the head. Don't lay them right over top of the spark plug holes, where they might ignite something coming out. Then crank it over and see what you get. You were running on two cylinders so you would probably have at least two strong sparks.

Try putting a few drops of fuel in each cylinder before you put the plugs back in. See if that gets it a bit more active.

I know you said you have a 4-into-1. Is your bike still running a stock air box or do you have pods? Cleaning carbs - the right way - is the remedy for 95% of "GS has been sitting, now won't start" issues. The guy who looked at your bike said it had weak spark on two plugs but not sure I'd take him at his word on that. He didn't even notice that the plug wires were not in their proper places...

[johnhend]

Splicing the Dyna wires in is pretty normal. With the points gone the other end of the wire goes to nothing.

A strong spark should be "fat" and blue. Weak spark would be thin and probably orange. I know that "fat" and "thin" are a bit subjective... Take your plugs out (are they wet w/fuel?), hook the wires back up, and lay the threads of the plugs against the head. Don't lay them right over top of the spark plug holes, where they might ignite something coming out. Then crank it over and see what you get. You were running on two cylinders so you would probably have at least two strong sparks.

Try putting a few drops of fuel in each cylinder before you put the plugs back in. See if that gets it a bit more active.

I know you said you have a 4-into-1. Is your bike still running a stock air box or do you have pods? Cleaning carbs - the right way - is the remedy for 95% of "GS has been sitting, now won't start" issues. The guy who looked at your bike said it had weak spark on two plugs but not sure I'd take him at his word on that. He didn't even notice that the plug wires were not in their proper places...

When I bought it the air box was dissasembled and the carbs had no filter attached. The spark is blue but looks thin. The spark plugs always come out dry and with a little soot. No fuel ever shoots out of the cylinders when I crank with the plugs removed. They are always dry. First thing I'm gonna do is remove carbs and dip overnight. I'll check the jets to see if they are still to spec. Now to figure out what the specs for the jets are..??

[exbellicus]

Parts Parts and More Parts
Alpha Sports
Babbittsonline
Bike Bandit
Carolina Cycle
Cycle Parts Nation
CYCLE-RE-CYCLE
Full throttle
Motogrid
MR Cycles
PartShark
Partsnmore
Ron Ayers
Z1 Enterprises

[mike_of_bbg]

Concentrate on the carbs. You're just not getting enough fuel. There used to be a sticky post with stock jet sizes, but now I don't see it. Search will probably get you there. Have you seen these rebuild instructions?:

http://members.dslextreme.com/users/bikecliff/images/vm_carb_rebuild.pdf

Do you have the stock airbox installed now (with a filter)?

[Suzuki_Don]

I'll check the jets to see if they are still to spec. Now to figure out what the specs for the jets are..??

Try these specs for your 550:

GS550L (77-79) the specs are for the VM's

idle r/min 1100-1200
carb mik vm22ss
id no 47110
bore size 22 (0.87)
float height 24.+/-1.0 (0.95 +/-0.04)
fuel level 4.0+/-1.0 (0.16 +/-0.04)
air screw 2.0 turns back
cut away 1.5
jet needle 5dl35-3 (the -3 3rd notch??)
pilot screw 1.0
pilot jet #15
pilot outlet 0.6
needle jet 0-6
by pass 1.0
main jet #80

[johnhend]

Thanks for the specs Don.

Yes, I have the stock airbox installed with a new filter.

[mehall2]

Hey John,

I picked up a 77 GS 550 this winter as a project and struggled like you with the spark. The coil resistance was marginal at best and the resistance of the wires coming from the points was bad. I bit the bullet, ripped the points, coils and plug wires out and replaced with Dyna everything. I've never see a fatter blue spark than that.

The biggest issue I've had was that I had to spend a lot of time with the carbs. You're on the right track with the intake boot o-rings. I know that o-ring guy on this forum has about every other o-ring but he doesn't have the intake boot o-rings for the 550. I got them at my local Suzuki dealer for cheap so you might try that. You'd be surprised at how many parts are still available through Suzuki for this old bike. Do yourself a favor and don't put the phillips screws back in - use the hex screws for the boots. You'll thank yourself later.

Someone posted a fuel screw air screw setting on this forum that worked for me also.

Fuel screw (these are the ones on the bottom of the bowl) - 5/8
Air screw - 1.25 to 1.5 out.

These settings worked for me too and the bike fires up every time, the first time.

Good luck with your GS550.

Cheers,
Mark