New Plugs/Caps

[Guest]

Hey guys. So, I got my bike running, now I need to get it running well. I want to replace the spark plugs and the boots/caps on them (because it's cheap and easy to do).

I think I got this right, but I was going to order 4 of the NGK B8ES plugs, as well as 12mm plug caps at 120 degrees. Looking at my old boots, I think the 120 degrees is right. Is the process for replacing the boots easy? Thanks!

Plugs: http://www.z1enterprises.com/ItemDet...item=TU38-0019
Boots: http://www.z1enterprises.com/ItemDet...item=TU38-1009

[wymple]

Mine has the 120 degrees on 2 &3, and 90 degrees on 1&4. Don't know how it was from the factory.

[eil]

You can replace the caps if you like, but the stock ones are pretty simple affairs. They twist off the spark plug wire and can be disassembled with a flathead screwdriver. Inside you'll find a resistor and a spring. If the resistor is shot (they often are), they can be replaced with a piece of metal the same length (I used hacked-off screw threads). Then just get BR8ES plugs with resistors built in to keep your bike from becoming a rolling RF signal jammer.

Z1 is good people, but the spark plugs are easily found at many auto parts stores for cheep. I got mine at Advance Auto Parts.

[Brendan W]

Mine are NGK, a reddish brown colour, 90 on 1&4 , 120 on 2&3. One exploded on the R100 one day. Quite a bang.

[srg]

Hm, I'm a bit confused. There's resistor wires, caps, and then spark plugs. What is stock on the GS550-LT? @eli mentioned removing the resistor in the caps (replacing it with a resistor in the spark plug), so if I'm understanding his post correctly, there should be only *one* resistor in the line (with OEM, it's in the caps), right?

[eil]

Hm, I'm a bit confused. There's resistor wires, caps, and then spark plugs. What is stock on the GS550-LT? @eli mentioned removing the resistor in the caps (replacing it with a resistor in the spark plug), so if I'm understanding his post correctly, there should be only *one* resistor in the line (with OEM, it's in the caps), right?

Correct! Suzuki put the resistors in the plug caps. If your resistors are bad, you would just be moving the resistors into the spark plugs. Again, this is somewhat optional, depending upon what degree you care about operating electronics near the bike while it's running.

If you want to replace your caps, that's fine, I was just saying that the stock ones are somewhat serviceable and unless they are crumbling apart, they are still likely to be good.

[srg]

Yeah, mine are actually crumbling apart.

What is the method for testing the ignition system (coils, timing, etc)? I got the PDF from BassCliff's website, but all that says is that the GS550-LT is fully transistorized and maintenance-free, and to just measure the resistance in the leads for continuity. Which leads is it referring to?

Thus far, I haven't touched (including testing) the coils, plugs, caps, or the signal generator at all. The bike is running badly and I'm working down the "Help! Your Bike Won't Run Well" thread checklist.

Thanks!

[eil]

Ah, okay. Didn't realize your originals were that bad off. I went and had a look at those Z1 caps you linked to in the first post. According to the description, they have resistors in them which means you can you run the spark plugs you already have. So ignore the rest of my rambling about resistors.

The service manual has some things to try as far as checking the ignition, so that would be your starting point. One thing I tried just this last weekend over at a fellow GSR member's garage: take out the spark plugs, then put them back in the caps and lay on them on the valve cover. Wave a strong magnet quickly past one of the pick-ups on the signal generator. Quickly, and as close as you can get without hitting it. Sparking should ensue. Repeat on the other pick-up. If you do this in relative darkness, you may be able to see if your spark plug boots or caps are letting the spark "leak" out where it shouldn't be.

[Redman]

..... and to just measure the resistance in the leads for continuity. Which leads is it referring to?

....\

Measure continouty from/thru cap 1 to cap 4 , should be about 30,000 ohms (30K). Same for 2 to 3.
Or take off the caps and measure each cap, should be 5K. And from wire to wire without the caps about 20K.

Replacement caps are about $4 or 5 each. Are not Suzuki specific, are NGK
The 1 & 4 are shorter and maybe 90 degree, the 2 & 3 are longer and maybe 120 degree.
On 1100G they are XB05F and VB05F.

The resistors can go bad over time and usage, weither in caps or sparkplugs.
My experience is that when they go bad they got to a higher resistance, so might measure, say, 15K on one cap, or might go completely open so measure infinite resistance.

.

[Steve]

Hm, I'm a bit confused. There's resistor wires, caps, and then spark plugs. What is stock on the GS550-LT? @eli mentioned removing the resistor in the caps (replacing it with a resistor in the spark plug), so if I'm understanding his post correctly, there should be only *one* resistor in the line (with OEM, it's in the caps), right?

There are actually three areas where resistors can be introduced. You already know about the plugs and the caps. If you replace the wires (not exactly an easy task with the stock coils), you can use "suppression" type wires, which basically have resistors built-in.

It does not really matter where you have the resistor, but you are correct, you only need ONE of the three types in use.

.

[srg]

Thanks guys! You've cleared up a lot for me. So the OEM wires would be difficult to replace because of how they connect to the coils, correct? So if I wanted to replace the wires too, I should replace the coils?

[eil]

I believe there is a tutorial on basscliff's site about replacing spark plug wires on the stock coils. If not, there are threads about it here.

I haven't done it myself, but it doesn't look too hard. It's mostly a matter of digging the old wire out of the epoxy, cleaning up the hole, and cementing the new wire in place with new expoxy.

[srg]

I found it, looks easy.

Last question. Since I'm replacing the plugs and caps, I want to replace the wires and the coils as well. I know Dyna is recommended for the GS. The caps from Z1 that match mine have 5k Ohm resistors in them. So I have to get a coil rated for 5k Ohms? So, these:

http://www.z1enterprises.com/ItemDetails.aspx?item=DYDC8-1

Or am I confusing that with something else?

Is it mostly "plug and play" or do I need to do something with the points too?

EDIT: Wait, I don't have points, do I? It's transistorized? The electrical/ignition system is something that I haven't learned enough about to be confident yet.

[eil]

Correct, you likely have an ignitor. See your service manual, it will describe the theory and operation. You want to get coils that match the stock ones, the values for which are also in the service manual. The values are for the primary side of the coils and the secondary side, I believe the primary value is the most important.

[srg]

According to this guide [1], the primary winding (between "input" wires) should be 2-5 ohms and the secondary (between HT "output" wires) should be 30-35 K ohm.

I measured mine. For both coils, the primary winding was 4.0 and 4.1 ohms; spot on. However, the secondary winding was 2.2 M ohms (M, not K: a scale of a thousand higher) and 14 M ohms. Does that mean they are bad (one is worse than the other?).

[1] http://members.dslextreme.com/users/...-ends.html#A17