Bike about died in rain......

[Redman]

Left home in a rain.

Rode about 15 minutes in rain, and then about 10 minutes in downpour, then about 10 minutes in drizzle, and then another 30-40 minutes with wett pavement.
Stopped at a rest stop for a few minutes.
When started bike it started hard, and running bad, -- real bad-- barley running, had to hold throttle open abit and was just barley idling, real ruff, stumbling, stumbling.
Would not at all rev. If I let off throttle it seemed worse, and if gave it more throttle it seemed worse .....
THought I was going to be dead-on-side-of-the-road about 60 miles from home.
But just let it continue to stumble and bumble for quite some time, like a couple minutes -- then WWHHHAAAaaaa upto 4000rpm, so let off throttle. And then all seemed back to normal.

I can only think that rain water got in somewhere.
Can say it dried out, so all is okay.
But also think that must be something that needs attention..... but dont have much of an idea ......... what?
Coils....?
Igniter....?
Wiring to igniter.....?

Any words of wisdon...? Any similar expereince...?

 

[fbody_mike]

How are the rubber ends on your spark plug caps, both the wire and spark plug side? Sounds like water may have gotten in a spark plug cap and caused a misfire.

 

[bccap]

I would suspect as the above poster stated. Used to happen to me every time I washed my bike until I dealt with the plug wires.

 

[Redman]

How are the rubber ends on your spark plug caps, both the wire and spark plug side? Sounds like water may have gotten in a spark plug cap and caused a misfire.

I would suspect as the above poster stated. Used to happen to me every time I washed my bike until I dealt with the plug wires.

Caps are fairly new (3-5 years)....
the rubber cap/boot on end of wire over the cap, that what you are concerned about???? I have never changed those since I have had the bike (2006). I dont know that they are split or ripped or anything, but maybe are kinda loose.

Not sure what all you mean by "rubber ends on your spark plug caps, both the wire and spark plug side".
I am thinking of the rubber cap/boot on end of the plug cap where the wire goes thru. I could see if those are still available and order a set next time I order some parts.

 

[fbody_mike]

The two rubber parts in this pic, one seals out the wire side, and the other seals the spark plug side.

 

[Cipher]

I would bet on plug caps as well. Not necessarily a time related breakdown of parts but number of hours run and heat cycling. They basically sit in an oven all their useful life. Pull them and inspect them. Its a 20 dollar swap

 

[Brendan W]

This is why WD-40 was invented.
It's HT leads imho.
Wiping them clean helps. Road grit and dust hangs on to moisture just that bit longer than a clean wire.

 

[Cipher]

oh and years ago I wient through a wet riding hell. Worse than the 73 buick which would shut off approaching a puddle.

I tokk my oem caps apart and found corrosion but yours are NGK replacements? Even so things die. Could be plug wire cross talk too its a nasty thing to try but in pitch black condition headlight fuses removed run the bike and spritz with salt water. If you see arcing then its your wires.

 

[Redman]

The two rubber parts in this pic, one seals out the wire side, and the other seals the spark plug side.

Oh.... boot on each end of the plug cap.
I recognize/remember the one on the wire end.....

... just now looked, yah, is one on the big end of the cap too, just that I never noticed it wasnt the cap itself. Must be that comes with the cap.

 

[Grimly]

Self-amalgamating tape works wonders on HT lead / cap joins. I put a few wraps around there on all plugs and haven't had a wet misfire (caused by that) for years. On one of my bikes I had all the HT leads sleeved with hose and taped, because I didn't know the trick with the sharpened tube and cutting out the epoxy around the lead at the coils, so had to soldier on with the old coils and leads. I've never had a Suzuki coil actually fail in use, but some have shown signs of being porous, so I've dried them out at low heat in the oven, and varnished them. No problems after that.
One of them is running CBR coils which have a nicely replaceable cap where the leads go in, and it's sporting some nice fat blue high-performance silicone leads (which probably add 100mph), just because they were available for free.

 

[dorkburger]

Agree with the rubber doughnut at the end of the cap. As Garth noted, my bike runs like poo after washing it. Dave, I had the same exact issue as you did when caught in a deluge recently. With the exception of the cap I replaced a few years ago, the seals on the others are confirmed dead - dried up, shrunken, and cracked.

 

[Redman]

Hum.,.,, I will have to look at both of those boots and all four plug caps.

Man, it sure seemed like went from running on 2 cyclinders (or maybe 1 1/2) for about 2 minutes, barley idling, then instantly back to normal.

 

[Brendan W]

Hum.,.,, I will have to look at both of those boots and all four plug caps.

Man, it sure seemed like went from running on 2 cyclinders (or maybe 1 1/2) for about 2 minutes, barley idling, then instantly back to normal.

Water boils

 

[Redman]

two points:

- I was thinking of what one thing would cut out 2 cylinders at once (and clear up at once). I was thinking one cap shorting to ground would not do it.
Now water getting in between the cap and the wire and if it made an open (discontinuity)(blocking the spark) - that could do it. I dont know if the water could cause an open.

- Ah, now I see, the replacement caps do include both of those boots.

I was thinking that have replaced all four caps maybe 8 years ago and the caps could be good for 10-15 years or lots more (and exhibit other symptoms as are going bad).
But, yah, the rubber boots may deteriorate lot sooner than that.
So could replace all four for about 20 bucks, just to feel better about riding in rain again.

 

[bccap]

I'd trim back the wires maybe a half inch or so if you're replacing the caps. The ends are likely corroded if they've been taking a bath......

 

[Redman]

I'd trim back the wires maybe a half inch ................

Did that in June when replaced plugs (when was having an other problem). Well, I cut off about 1/4-3/8th to where was more "wire" material.

 

[Tom R]

How’s the ignition cover gasket?

 

[red1100]

Dies in rain

Dies in rain

Tom R, your probably on the mark. My then new 74 GT 750 would die when the weather changed instantly from sunny and clear to a hot humid thunderstorm. This was in South Carolina where thunderstorms are daily. I would stop and remove the points(yes) cover and spray everything with WD40. Put the cover back on,fired right up and rode home. I temped it for awhile with a packet of desiccant that would at least get me home.

 

[Redman]

How’s the ignition cover gasket?

Hum..... ponder.... ponder..... sounds like a valid concern..... ponder.... ponder.....

To answer your question: Seems to be be the original paper gasket. Thin, dry, paper gasket. It all stays on the cover when remove the cover (which had done in prior week for valve shim adjust.) So have never replaced it. Always had thought that the gasket served no real purpose since no oil in there. Duh- didnt think of keeping rain OUT. Doah.

Maybe should put a little bit of grease for a water seal on the paper gasket, and maybe on the bolt heads ..... I dont know.
Maybe I can inspect that gasket, with more critical look along the outer edge where the cover meets the engine.
Ah, Maybe order a new gasket.

Ponder.... Ponder.... with my lack of expereince ..... ponder... ponder.... with my limited understanding (but lots of troubleshooting other stuff experience) ...
Seems like anything in there would effect ALL the ignition, like completly dead. I understand the pickup is two wires, and a positive pulse on both wires triggers one coil and a negitive pulse on those same two wires triggers the other coil. So, makes me think any problem with those wires would effect both coils so would have NO ignition.
At least that is my guess. Butt I suppose maybe something that degrades any signal on those wires could make the ignition weak and erratic.

When it was running bad, barley running, barley above idle, it was a fairly constant bumble-stumble-bumble-stumble-bumble-stumble, then in an instant whaaaaaaa 4&5 thousand rpm, let of the throttle and settled down to normal idle.

.

 

[Burque73]

I cut that gasket out of a corn flake box. Doesn't seem to cause problems when it rains.