Heavy rain, bike cuts off

I got caught in a heavy rain today, and when I stopped for a red light the bike cut off. After a couple of minutes it finally started but every time I stopped or let it go to idle it would cut off, and after a couple of minutes and several efforts it would always start and run well as long as I kept the rpms up. I have also had it cut off for no apparent reason several times in the last couple of months, and sometimes it starts quickly and sometimes it takes a couple of minutes. The bike is absolutely bone stock, 17,000+ miles on it, starts easily, and runs and idles well, except for today and the few shut offs over the last couple of months. I’m almost certain that it is an electrical issue but not sure where to start. Any suggestions?

 

Somehow you have to figure out what is exactly happening. Losing spark? Trace it from the plugs up through the entire circuit until you find the component causing the issue. This can be difficult as you have to get the issue to happen in order to immediately start troubleshooting before whatever it is to start functioning again, ie when it starts back up and runs until it acts up again.

 

wet coil packs or spark plugs arcing out? see if you have a night time light show. spray some water on them with a spray bottle.
check your battery resting voltage and then start bike and look at the idle voltage, inspect connections for charging system.
inspect and clean connections for ignition system. check voltage drop at connectors. start at fuse and move forward.

does it only cut out at stops or at idle? except for your last rain trip.

how old is the fuel filter?

 

Fuel filter about a year old. No more than 3,000 miles on it.
I’ll look for the light show tomorrow night, too late and wet tonight.
I’ll check the battery also, but it is about 6 months old, stays on trickle charger and turns the starter strongly.
(Wonder if the charger pigtail hooked to the battery could cause the problem when wet?)
I hate electrical issues, but I’ll look at the fuses an connections.

 

When was the last time you cleaned the sidestand switch?

 

Definitely check out the coils and wires. My Maxim would do the same thing when I got caught in the rain, was able to replicate with the spray test at idle. Coils were visibly cracked but I never got around to replacing them or the wires.

X2 on @k-moe on that suggestion. About a year into riding mine would start cutting off randomly. After she shutdown mid left turn I cleaned the switch up, lubed it, and never had a problem afterwards.

 

Your comment "I've had it cut off for no apparent reason in the last couple of months...."

Fuse box replaced? Mine would totally die, then restart after a few minutes until I replaced the fuse holder.

 

^^^+6 agree with all replies , You should pull tank and look carefully at the coils remove them and look at bottom if they are cracked replace them. Look at all your grounds a little corrosion and also cause issues when wet .

 

I've never cleaned the kickstand switch, but that is one of the places I had planned on checking. I'm definitely going to look at the coils, but the last time I looked I didn't see any cracks, but it wasn't a really close inspection. The fuse box is stock, so it needs to be looked at also. I'll do all that tonight/weekend, but I especially wanted to look at areas that might be affected by rain and road splash--coils and side stand switch certainly qualify. K-Moe, assuming that the side switch is ok when dry, would water cause it to malfunction, and if so wouldn't it cause the bike to shut down at any speed? The pigtail for the battery charger also is out in the open, so could that also be a problem if wet.

Thanks for all the suggestions. I'll let you know what I find, if anything.

Did I ever mention that I hate electrical issues??

 

Since that is usually connected to the battery, it would cause more issues if shorted and it should be fused anyhow. If shorted the fuse would blow.

I would definitely look at and clean up the fuse box. Better yet just replace it as they are known failure points.

 

You are right, there is a fuse on the pigtail. I had forgotten about that. One thing eliminated. Thanks.

 

To answer your side stand switch, it's possible that water would cause it to short and shut the bike down but it's more likely that it is gummed up. There are three wires to the TCI to test. Ideally you can test right after the bike shuts down but you should see:

• 12 Volts when testing to Red and Black Wire on TCI with ignition on. If that fails then:

1. Test meter probe to Red and other meter probe to battery ground. If good then you need to troubleshoot grounds.
2. Test meter probe to Black and other meter probe to Battery Positive. If good then look at Fuse box, Ignition Switch, and Run switch as something is preventing power to the TCI. Easiest sopt to check is at the Ignition fuse with the key on. Should be 12 volts there with one probe on ground. Check both sides of fuse. The fuse is after the ignition switch.

• If you have 12 Volt on black and red then:

1. Test Red to Black/White wire with side stand down and in Neutral. If you see 12 volts then the safety circuit is shutting down the TCI by grounding the black/white wire.
2. If the neutral light works, it is most likely the sidestand switch. Clean, lube, and test again. You can remove the sidestand relay to defeat the safety as well for testing.

I hope that helps!

 

Now you really know how little I know about electrical issues--where is the TCI on my XJ700?

 

Wherever the factory put it!

I have no idea as I've never had that bike

No 7 in pic below.

 

Thanks, I've never had a need to look for it.

 

No worries, I'm working on a Vulcan at the moment and it took me forever to find a damn diode module in the wiring harness. Not used to the bike.

 

Not likely. The temperature change when wet (unless you live in a really warm place it's not typical to have warm rain) could be enough to cause any gunk in there to gunk up more, causing the switch to stick. My main reason to have you check it is because you siad that the bike has been cutting off randomly for quite some time, so it may not be rain-related.

 

Are you running PODS ? Bikes don't like running on water!

 

Completely stock, right down to the oem paper filter.

 

If the side stand switch was the issue then it should start right up after dying if the bike was placed in neutral since the side stand relay is controlled by either the neutral switch OR the side stand switch. Additionally, if you were stopped at the light and in neutral when the bike died then that would also rule out the side stand switch.

Having to keep the revs up to keep it running would seem to indicate low fuel levels or missing cylinder / cylinders firing.

Since your bike already has the blade fuses there would not be an update to perform (excepting the main fuse), but that doesn't mean they shouldn't be inspected for corrosion (as well as other connectors) for possibly degraded contacts causing some voltage drop resulting in ignition issues.

 

I still have the original fuses, which I will be checking this weekend.

 

Apparently not the coils or plug wires. I just drenched both coils, plug wires and plug boots and didn’t see any sparks and it didn’t effect the idle at all. Looking at the fuses, battery connections and side stand tomorrow.

 

just dont get lost about the rain , you stated it happened when not raining to. chech on the connector from the right control to the main harness

 

Finally got a chance to work on the bike today. (I have been fighting fuel injector change on my 280
ZX). Bike started instantly (no choke), idled and warmed up fine. Using a hose and spray nozzle I drenched the carbs with no effect. As soon as I sprayed the right side plugs and wires it shut down. Removed the caps, which were dry, reinstalled them and it started instantly. Sprayed again and it immediately shut down. Again removed the plug caps, put them back on and it starts instantly. Repeated on the left side and got the same results. So, it appears that the rain is shorting out the plug wires, caps or both. I am going to try again tonight but last week when it “misted”the coils, wires and plugs I didn’t see any shorts. Maybe it just needs a lot water to short out. If it turns out to be the wires is there an easy and safe way to splice in new wires? Not really interested in replacing the coils.

 

Spark Plug Wire Splicer:

pw1) Aftermarket NGK-brand SPARK PLUG WIRE SPLICER. This handy little device allows you to cut off a bad original plug wire and splice in a replacement piece, which is really handy, since the plug wires on the original factory coils are basically non-replaceable......so if a plug wire goes bad, unless you are willing to perform "coil surgery", then the whole coil is junk!


This plug wire splicer or "joiner" allows you to extend or replace a damaged or bad plug wire, just like you would splice into a piece of electrical wire. The watertight, screw-on design is made from a high-impact plastic material and adds no resistance (0 ohms) to the circuit. Will accept either 7mm or 8mm plug wire (but no larger).....meaning you can also use this to splice original 7mm plug wires to aftermarket 8mm wires. A very handy and practical solution!


HCP2789 Aftermarket SPARK PLUG WIRE SPLICER, fits up to 8mm plug wire. Each:

 

Sounds like a plan if it turns out to be plug wires. If I don’t see any sparks tonight then i’m Not sure how to check for shorts. Any ideas?

 

Well, it fired up tonight and no amount of misting or water will produce any arcing or “light show”as they say. However, it appears that if enough water gets on the plug wires and down on the plug caps it will start to skip and/or cut off. The caps appear to be dry inside, but I’m wondering if so how the water is shorting out the plugs. Any ideas?

 

I would go with new caps first. The Bakelite gets brittle and will pass liquid and ground the coils.

 

Guess I know where I'm starting my search and working back from

I just got caught in my first downpour yesterday and had the same thing happen

like a cylinder just cut out and then came back on as I was able to get the revs up and dry things out after the storm

 

I’m thinking it is the plugs shorting out with water entering where the porcelain meets the metal. At least I am going to replace the plugs and check before messing with the caps. I’m not sure why wet or leaking caps would be a problem anyway. I’ve used a lawn mower in the rain many times and it just has an exposed metal plug wire end. But perhaps these resistor caps make a difference . I am using the proper NGK plug but I may try another brand.

 

Got the bike good and warm with a good idle and used a large syringe filled with water and sprayed each plug wire (where it connects to the cap), cap and plug one at a time. Enough water would stall it. If I let it sit for a minute or so giving it time to dry it would fire up easily. If I blew it with compressed air it started sooner. Three conclusions: it takes a lot of water; when it dries it starts again; and, it only happens at idle. So it must be shorting somewhere but I have not seen any arcing. I removed all caps and all were good and clean except one that was slightly corroded. I think they have already been trimmed once, so I cleaned all the connections, added some dialectic grease and reinstalled the caps. Don’t know if this will solve the problem, but if not then I will have to replace the wires since I don’t have room to trim a couple of them. I still don’t know where the shorting is since I can’t see any arcing and inside the caps is dry. Any ideas where it might be arcing?

 

I'd assume that it's arcing everywhere and replace the wires, and caps.
Ether that, or don't ride in the damp.

 

Probably so, but it irks me that I can’t see anything at all. I’ve had the same thing with cars and it always looks like a fireworks display.

 

run your fingers down the wires, when you find the bad spot you'll see all kinds of fireworks

 

Now, I may be dumb, but I ain’t that dumb!

 

Oh but the look on your face would be priceless!

 

NGK has some versions of the plug caps that are supposed to be better water sealed.

FWIW, I'm running VB05F (2/3) and LB05F (1/4) plug caps on my setup. These are not the extra water resistant type, but I remember one soaking ride where I was utterly drenched, but the bike had no problems at all.

Edit: Looks like the more waterproof ones would be LB05FP and VB05FP (to maintain matched caps and still have the 120 degree angle that better fits the inner cylinders).

 

Tabaka45 just remember you said this was also a dry weather problem too.

 

There might be more than one problem.

 

Actually the water problem is probably separate from the couple of “dry” cut offs. Sometimes after a ride when the engine is fully warm and I let sit for 45 minutes or so, it will start easily, idle a little low at first and it might cut off at idle until it is fully hot. Then it might take a couple of tries before starting again. It really acts like a cold start. Maybe the bike cools off faster than I thought it would.

 

It might be that a coil is failing. Temp related failure is not uncommon in older coils.

 

I hope not, cause it’s running really well except for the wet issue.

 

To me it sounds like your caps are not protecting well against water. I'd say to try the NGK caps I suggested. They're only a few dollars a piece, and they're easy to replace.

 

After a good bit of reading, I discovered that dielectric grease could be used on spark plug caps to provide waterproofing and prevent arcing. So I have coated the inside rubber of the cap and also the inside of the cover where the wire inters the cap. We’ll see if that helps. If not then I’ll look at replacing caps and wires.

Interestingly, what I read said not to coat the metal on the plug or inside the cap. It said that dielectric grease is not a conductor but an insulator and might increase resistance. Yesterday I coated the wire endings and the screw tips in the caps. I didn’t notice any change in the way the engine ran, but I may try to clean those and just stick with the rubber parts. So I learned something because up until now I used dielectric grease on electrical connections thinking it improved the connections. Live and learn.

 

Any good fitting terminal will scrape off the grease and allow for good contact.
Applying dielectric grease was SOP when I was doing machine maintenance.

 

dielectric grease is also known as bulb grease and is smeared onto the bulb base. thats metal