Started right up, washed it, not starting, backfire

[Guest]

So last week, after the 4 month long ice age here in NJ, I decided to try out my new Motobatt battery (its awesome, BTW). Put it in, primed the carbs, hit the starter, and boom, it started right up.

I noticed that the number 1 cylinder exhaust header was cold after a few minutes, but figuring maybe something was clogged up or gunky, I went for a quick ride around the block. Literally around the block. I got back, pulled in the driveway, and the number one cylinder was running like a champ. I let the bike run for another 20 minutes or so, and after about an hour. I decided to wash the bike. I took great pains to avoid getting water near the battery or any electrics I could see. I did run water over the engine.

A few days later, I go to start the bike up, and nothing. I turn the tank to prime, wait a few seconds, and hit the starter again. Nothing. I let the starter run for a maybe 3 seconds, and I get a huge backfire. Like fireball backfire.

So over the past week I've been trying to start it up no avail. Today, I checked to see if the number one cylinder was getting spark by removing the spark plug and laying it against the engine case while hitting the starter, and no spark. The plug was also very black. I take off the tank to check to see if maybe I knocked a wire loose on the coil or something, and it all looked good. I put the tank back on and hit the starter and I get a HUGE backfire that I could see went about 10 feet out my exhaust and actually pushed the baffle out of the can.

Obviously it is sometimes getting spark and fuel if it's backfiring. Maybe a lot of fuel. The thing is, it won't even catch or stumble. At one point this week, while playing around with the bike, I noticed that after trying to start it for about 15 minutes (on and off, obviously), only the number 3 cylinder was warm to the touch, all others were cold.

Any thoughts? What should I check first?

[GSX1000E]

Perhaps you accidentally left the petcock on PRIME? Check for gas in the crankcase.

[chuck hahn]

Youve sucked crud from the tank into the carbs most likely. That or the coagulated crap from inside the bowls has jammed things up.For any long term storgae you should drain the bowls, fill the tank to prevent airspace for condensation ( or drain it and fog it with some WD40 or other oil that will coat the insdie ).

I also add a good dose of Stabil for Ethanol Fuels to the gas tank. The back fire was probabkly from raw fuel that hade passed thru into the pipe and she ignited inside the tube.

[dorkburger]

My cycle is quite cranky after a long layup. I suspect something may have gotten wet during washing. Lsst year after its yearly wash, my cycle wouldnt start either, dut did a couple of hours later. I did find in a different situation, corroded plug wire connections at the cap and coil connection (1150s wires are removable at the coil) and a bad cap. Addressing this cleaned up the plug color. Id thoroughly check for water first before going crazy. And what GSX100E said as well.

[Steve]

You could also try using WD-40 for the purpose for which it was designed.

Water Dispersal.

Spray some on all your plug wires, all the way from the coils to the plugs. I use a rag to catch the overspray and coat the back side of the wire.

30-year-old plug wires will tend to have a BUNCH of small cracks that attract water. WD will chase the water out.

.

[AX2007]

Perhaps you accidentally left the petcock on PRIME? Check for gas in the crankcase.

No, I always make sure to turn it to "ON".

[AX2007]

Youve sucked crud from the tank into the carbs most likely. That or the coagulated crap from inside the bowls has jammed things up.For any long term storgae you should drain the bowls, fill the tank to prevent airspace for condensation ( or drain it and fog it with some WD40 or other oil that will coat the insdie ).

I also add a good dose of Stabil for Ethanol Fuels to the gas tank. The back fire was probabkly from raw fuel that hade passed thru into the pipe and she ignited inside the tube.

The tank was full with Stabil treated gas. I read my BikeCliff before doing anything on this old lady

[AX2007]

My cycle is quite cranky after a long layup. I suspect something may have gotten wet during washing. Lsst year after its yearly wash, my cycle wouldnt start either, dut did a couple of hours later. I did find in a different situation, corroded plug wire connections at the cap and coil connection (1150s wires are removable at the coil) and a bad cap. Addressing this cleaned up the plug color. Id thoroughly check for water first before going crazy. And what GSX100E said as well.

You could also try using WD-40 for the purpose for which it was designed.

Water Dispersal.

Spray some on all your plug wires, all the way from the coils to the plugs. I use a rag to catch the overspray and coat the back side of the wire.

30-year-old plug wires will tend to have a BUNCH of small cracks that attract water. WD will chase the water out.

.

This makes the most sense, given the sequence of events. I'm going to try the WD-40 trick. It seems someone took the time to make my coil wires removable as well, with a spade-type connector.

I'll coat the wires and the plugs. Should I also get the inside where the coil connects to the plug?

[AX2007]

Just to be clear, I sprayed WD-40 on all the wires and connections. The spade connectors are not one the side of the coil that goes to the spark plugs, they are on the other side. I sprayed those as well. I'm wondering if perhaps water got into my distributor (or whatever its called) on the right side of the engine. Going to check there too.


Following the wire out of the "distributor" I noticed that the white sheathing that surrounds the two wires that leave the sheathing are completely soaked through. It seems like water, as it didn't smell like anything else. I untucked the wires from between the frame and the engine and let them hang out to dry. I'll try it again tomorrow, after everything has some time to settle down. Nice weather today and tomorrow should help also.


This is my first time washing anything beyond the wheels on this bike.

[earlfor]

10 to 1, the old wiring harness and plug wires have cracks that allow water to soak in, shorting out the ignition system. Soaking everything down with WD40 to displace the water/moisture is probably the way to go. It will take a little while for the WD40 to soak in and do its job. Also, take apart electrical connectors and spray them too before reconnecting them. I betcha your connectors are not water proof.

[AX2007]

10 to 1, the old wiring harness and plug wires have cracks that allow water to soak in, shorting out the ignition system. Soaking everything down with WD40 to displace the water/moisture is probably the way to go. It will take a little while for the WD40 to soak in and do its job. Also, take apart electrical connectors and spray them too before reconnecting them. I betcha your connectors are not water proof.

You are 100% right. The connectors I saw are just plain old spade connectors.

Whether this ends up being the cause or not, any thoughts on what I can do to replace those connectors?

[eil]

That kind of a backfire usually points to an intermittent spark. You weren't getting any spark at first, then did some messing around, tried again, and then all of the fuel collected in the pipes finally caught and BOOM!

Can't offer anything above and beyond what has already been suggested, but it sounds like you're on the right track.

[bccap]

I had the same problem with my 88 Kat including the back fire. It happened a few times after washing it but always started the next day. Last time it didn't, even after a week. Finally I changed the plugs and it fired right up. I still haven't dealt with the problem but I suspect the plug wires as well. I'll probably change the coils at the same time. Too much of a PIA dealing with that glue and dyna coils aren't that expensive....

[earlfor]

You are 100% right. The connectors I saw are just plain old spade connectors.

Whether this ends up being the cause or not, any thoughts on what I can do to replace those connectors?

I had a water intrusion problem with my 1150E. Every time I got caught in a shower and had to ride in the rain, after ten minutes, the harness collected enough water in the connectors to short out the ignition and it would start backfiring as I was going down the road. Once everything dried out, it was back to running normally. My problem was the connectors and the big 9 pin plug in the harness that was above the valve cover on the right side. It filled with water. After getting everything dried out and the bike running normally, I put three or four tight wraps of electrical tape around every connector and harness plug. I also put electrical tape wraps around the top of each spark plug cap to keep water from draining down into the caps and sprayed the plug wires and caps with WD40. It solved my problem.

Crimping on new insulated spade connectors will probably help also. I would still do the electrical tape wrap on them though.

[AX2007]

A late update: Pulled the plugs, and they were black and fouled, I'm guessing from trying to start it so many times. Replaced the plugs, and the bike started right up. Success!


Thanks for all the help guys. I love the sense of the community on this site.