1st post, novice mechanic. Spark plug/boot/wire screwup, among other things

[newdude90]

Hey all, and thanks in advance for welcoming me into your community. I bought my first motorcycle, my 1985 GS550L in November, and have put many miles on but have a total lack of mechanical knowledge, and I'm trying to change that. I've been reading and researching for hours everyday for weeks, and yet I still feel like I know hardly anything at all, and I'm ready to have my hand held through some problems that I want to fix myself, but am so tempted to bring to a pro mechanic. Let's see if I can do this with your help!

The details:

Bike is far from perfect, and I think there are a few issues occurring simultaneously, so let's see if you can weed them out. It doesn't do well in rain. The first time I rode in rain, I could swear the engine started smoking and smelling, so I was convinced I'd run out of oil! (I'd noticed a leak a few days before, and I hadn't checked my oil level before riding). But I checked and I still had plenty of oil. The next time I rode in rain, the engine started sputtering: inconsistent idle, then it wouldn't idle without the choke (it'd stall) then on the highway I was accelerating until I hit 6th gear, was cruising, but when I tried to go WOT the power wasn't there, it felt like I was out of gas, sputtering then finally coming to a stop (I wasn't out of gas). I could get it started again with the choke on, but then it would over-rev, and it would stall almost immediately when I took the choke off.

After much reading it seemed like these are all classic symptoms of running lean. Probably vacuum leaks. But I checked for vacuum leaks and there didn't seem to be any big problems.

I start it up the next day (when it's dry) and it runs fine. WTF!? So I refine my research, looking for problems in the rain. Now people on forums are saying it's probably a short. Water gets in somewhere and shorts the ignition circuit.

Problem #1: despite looking at several youtube videos and hearing many explanations, I have no friggin clue how to check for shorts. I see a bunch of wires strung all over my bike and I have no idea what they do or what a short even is or what ground cables are or how to check fuses or any of that. It's all gobbledegook.

So instead of addressing that short (because it's riding fine as long as the weather's nice) I'm still worried about running the bike lean, so I figure I can do a quick check of the spark plugs. So I take out the spark plugs, notice they're pretty grimy/gritty, so I do two things that were maybe stupid.

Firstly, I cleaned them with heat. I saw a guy doing this with a propane torch and my common sense thought that's probably not good but the method was backed up in some forums so I did it. Secondly, for lack of a proper cleaner, I sprayed a little "stainless steel cleaner" on them, and scrubbed them with a brush. Actually, I did that first, and the flame second, so even if that stuff wasn't great I figure I probably burned it all off anyway.

My spark plugs look white so I'm worried because I keep hearing that's a sign they're running lean, but after looking at dozens of pictures I saw plenty of examples that look just like mine and they say these are examples of perfectly operating spark plugs, so I'm actually confident that I'm ok. One of them even looked a little dark and carbon fouled, though maybe that was just some crud. Came right off with the torch.

Problem #2: When I put the spark plugs back in and attached the boots, I tried starting my bike and BOOM BOOM BOOM! The bike starts, but won't idle above 1000 and the exhaust is backfiring constantly!

So I really screwed up. One explanation is that I crossed the wires. I'm nearly positive I didn't but I can't find the correct configuration in either the owners manual or my service manual so I have no way of knowing for sure. Another explanation is that I created a short somewhere. I don't understand this but a reddit user was trying to tell me that's probably what happened. Or maybe through my cleaning I just completely screwed up the plugs and need new ones.

But what if it's the wires? The boots are super old, and I don't see cracking but who knows. So I have a new set of wires in my cart on Amazon, but I wouldn't even know what to do with them because of

Problem #3: How the heck do you take the gas tank off this bike? I need to do it to install new plug wires. I undid the bolts, and I disconnected either the fuel or vacuum line, not sure which, but the other tube won't come off for the life of me. And then on the other side there seem to be 2 wires attached to a circular thing on the inside of the tank. The manual makes no mention of these. So I have no idea how to safely remove the tank.

OK, I think I'll stop there for now. This is a bunch of information but hopefully the discerning of you can weed out the important bits and come up with a diagnosis and give me some guidance. All your help is much appreciated. I'm earnestly trying, but I feel like I just need to take a class or have someone show me exactly what to do, because I just spent literally the entire day working on this bike and accomplishing nothing, because I don't know enough to help myself.
Cheers!

 

[Planetsmasher]

Ok, well for starters.. to get the tank off = Undo the bolt at the back(next to the seat). grab the back of the tank and lift up and pull back a LITTLE. its just pushed onto two rubber grommets up front under the steering yolk. Basically the bolt is the only thing that holds it on firmly. The rest is kid of a friction fit. Once you lift the back up a little, you'll be able to fiddle your hand under there and undo the other line you couldn't reach (vac or fuel). once its undone just pull the tank back. there are no other fasteners.

 

[Planetsmasher]

Now as far as the coils, see here: http://zeus.mtsac.edu/~cliff/storage/gs/GS550_77-82_all.pdf

Page 139. This was courtesy of Basscliffs website. If you are around here for very long he will likely introduce himself. seeing his website is akin to finding a brick of gold lying on the ground. Endless useful info.

 

[JRHemmen]

While there could be a number of issues causing your spark issue, it's possible you disrupted the connection from boots to wires. If you're able to pull the boots straight off the wire, then you don't have a great connection. Take a pair of dykes and cut about 1/4" off of the wires from the coils to the boots. Now stick the end of the wire in the boot and twist. The boots should thread themselves into the wire and give you a new clean connection. It's also possible that you messed up your plug gap while scrubbing, but that's unlikely in my opinion. Even if you aren't an electrically inclined person, I would highly recommend doing the coil relay mod found on basscliff's site. I'm sure a number of us would be willing to walk you through the process. Basically, you use the old power wire for the coils to switch a relay, allowing the coils to be powered by brand new heavy gauge wire coming straight from the battery. Think of the relay as a floodgate, when power is received from the old coil power line, it opens up a gate allowing power to flow from the battery straight to the coils, avoiding 30+ year old corroded wire along the way.

Welcome to the forum!

 

[JRHemmen]

Also, if you even think the bike could be running lean, remove your intake boots and inspect the O rings inside. No point in running around a bunch of other issues when that's so often the cause. If the O rings are flat, replace them, they're cheap and will save you a lot of headache. If the boots are cracked and hard, I'd think about replacing them too, although they're certainly not quite as cheap (~$30 each).

 

[fastbysuzuki]

You need to get a base line to start with you will not get far poking a stick at it have a look here
http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

 

[Brendan W]

Crap running in the rain is most often sparks leaking out from the plug leads either because they are cracked or there is a bad connection in there and the sparks try to take the easiest route to ground. Running the bike in the dark will sometimes show up where the sparks are leaking out. A spray of WD-40 along the lengths of the plug leads will help after you wipe them clean. Road grit holds on to moisture and a dirty lead leaks sparks quicker than a clean one. The cores of the leads corrode where the cap screws in. This high resistance will encourage the sparks to jump ship. As mentioned cut the last 1/4 " off or until you can see clean bright core wire and refit the caps. Generally the right configuration for the plug leads is the left coil supplies cylinders 1 & 4 ( numbering from the left as you sit on the bike) and the right coil supplies 2&3. Doesn't matter which but the wires may be of slightly different lengths making it easier to fit one way rather than the other.

 

[newdude90]

Thank you all for the input. Can someone quickly explain how multi-quotes work? I'd like to address all of you in one post but after I click the multi-quote button I'm not sure what to do. Cheers!

 

[Brendan W]

Multiquote is the quote button with the + sign bottom left at the bottom left of the post.
Click on each post you wish to reply to and then you can type in between the quotes in the reply window.
Worst that can happen is you crash the forum server

 

[cowboyup3371]

You'll have to click on the Quote+ button for each person you want to quote then choose the Reply With Quote on the last thread. This will show each person