1983 Suzuki GS 550 E @12,000 original miles

[Schweisshund]

Ok ........... here is what has happened so far. Apparently, my bike is possessed.

I attached booster cables to the battery from a non-running car battery. I cranked it, same thing. I did this in 5 second cranking intervals - waited 15 seconds, and I did this about 4 times before it started to act like it was catching. Then BOOOOOM ..... loudest backfire ever and smoke came out of the right tailpipe. Scared me, my little chihuahua and my neighbors. Smoke continued to come out of this tailpipe for some time.

Meanwhile my neighbors are eyeing me like cheech and chong from up in smoke.

[Schweisshund]

What's the firing order?

I have my spark plug leads from (as your sitting on bike) left to right in this order 1, 4, 2, 3

I am using a manual on GS650 fours (mine is GS550).

Is it possible the backfire was a result of spark plug wires being in the wrong order? Also, the smoke coming out of the tail pipe was similar to when it was being cleaned by seafoam. I did add a little bit of seafoam deep creep to lubricate the jets.

[txironhead]

Yep, definitely wrong. The cylinders are 1-4, left to right as you're sitting on the bike. That would most certainly cause a backfire.

[Schweisshund]

Is the firing order 1-4?

Here is my set up - and the firing order according to the GS 650 manual I have :

Sitting on the bike left coil with two spark plug wires from left to right - the left lead goes to cylinder 1 the right lead goes to cylinder 4

The right side coil with two spark plug wires/leads the left lead goes to cylinder 2 the right goes to cylinder 3.

Should left coil be for cylinders one and two and right coil be for 3 and 4?

Might be narrowing down this problem.

[MelodicMetalGod]

Is the firing order 1-4?

Here is my set up - and the firing order according to the GS 650 manual I have :

Sitting on the bike left coil with two spark plug wires from left to right - the left lead goes to cylinder 1 the right lead goes to cylinder 4

The right side coil with two spark plug wires/leads the left lead goes to cylinder 2 the right goes to cylinder 3.

Should left coil be for cylinders one and two and right coil be for 3 and 4?

Might be narrowing down this problem.

According to my FSM for 1983 GS550E and ES, firing order is 1, 2, 4, 3. I highly recommend that you download the FSM from RepairManualClub.com. Information in hand will save time AND money and lead to lower stress levels. :-D

[Schweisshund]

Thank you for that link - much appreciated \\/

[txironhead]

Not sure what the firing order is for your bike, honestly, but if you have some of the plug wires switched that would definitely cause a backfire. The factory wires on my bike actually have the cylinder number printed on a white ring around the wire, makes it really handy when I change the plugs.

I remember wiring up my F150 with the 351M one time. My nephew was helping and had removed several wires and couldn't remember which went where. I followed the firing order stamped in the manifold, going by the 1-3-5-7 on the left bank, etc. that I was used to. After scaring the crap out of both of us with a backfire out of both glass packs, I decided to go get the manual. Lo and behold, on the 351M, the cylinders are not stagger numbered like most engines, the left bank was 1-2-3-4, etc. I had the firing order right but the cylinder numbers wrong. Just goes to show how one simple oversight can lead to serious engine problems and a wasted afternoon (or longer).

[Schweisshund]

Lol - I am using the wrong manual for my bike (GS650 1981-1983) mine is a 1983 GS550E and I am not even sure if the cylinders are staggered or if they go 1,2,3,4 or 1,3,2,4 or what.

As for the backfire on your 150 - I can relate - it sounded like a bomb had exploded in my garage when my bike backfired. I had a profoundly deaf friend visiting (not kidding) that was inside the house and felt it. :shock:

I was sent a very helpful link by another GSresources user and am downloading, I hope, the correct manual for my bike.

[Schweisshund]

My hat is off to gsresources member melodicmetalgod - the link you sent me http://repairmanualclub.com was an absolute lifesaver. Because of the excellent illustrations showing the spark plug wiring diagram, I was able to see immediately I had leads number 1 and 4 confused.

To explain this more in depth - I thought the left coil was 1, 4 (from left to right) and the right coil was 2,3 (left to right).

it wasn't ....... its from left to right (spark plug wires exiting coil) 4, 1, 2, 3 for the 1983 Suzuki GS 550 E, ES and L models. The cylinders are from left to right 1,2,3,4

will try to put this in perspective the best way I know how

spark plug wires exit coils = 4,1,2,3
cylinders 1,2,3,4

far left coil wire goes to far right spark plug

If it is not placed on this order then you will hear a sound much like a 50 caliber desert eagle being fired right next to your ear.

[nabrams]

So it's running now?

[MelodicMetalGod]

Glad the FSM is helping out. Remember that the FSM, Clymer and Haynes all have varying pro's and con's in terms of the information and presentation, so you would be wise to get at least one of the Clymer or Haynes manuals as well. I've got the Clymer and it's more slanted to the earlier models, so I'm planning on adding the Haynes to my collection as I understand it's a bit more relevant to the later models.

Best of luck!

[Schweisshund]

disregard my last post - re: I had the connections on right the first time. I was looking at the diagram for the 1983 Suzuki GS 550 L and the wires are routed differently than the E model. Once again, the backfiring is present and it won't start. It smells like starter fluid and spark plug 3 and 4 were wet. I just replaced those champion spark plugs with the NGK's and will see if there is a difference in the morning. Does anyone know how to adjust the timing? I have the downloaded manual but its not very clear.

[txironhead]

Are 3 and 4 on the same coil? You could have a bad coil, fairly common on these bikes. If they're not, then it could be the timing or bad CDI box.

[Schweisshund]

3 and 4 are on seperate coils. I suspect its the timing too and have never adjusted the timing on anything ever. I have the timing specs in the manual I downloaded but I don't even know where to begin. The manual assumes I know how to adjust the timing and does not explain how to go about it. Maybe I am overlooking it.

Am I right to think BTDC means below top dead center? And what exactly am I lining up? the pistons in the combustion chamber? Do I have to remove the head gasket to adjust the timing? I have been searching the forums to find out how to do this.

There should be a new forum specifically related to "How To" (How to replace a tire, how to rebuild brake master cylinder ...etc.)

[txironhead]

Actually, it's Before Top Dead Center, but you were close enough. Start a thread on timing your bike and you'll get plenty of help from these guys. I know that your bike is a bit different than mine in the timing department, so I can't help you there.

Is there anything in your manual on testing the CDI box?