P 250 Stalling in the rain

[TechGuy]

I have had the bike, a People 250, since July 2008. I have ridden about 13,000 KM since then with zero mechanical issues. It was in the low 50's F, it was raining pretty continuously and had been for the 4 hours prior to my ride home. I was splitting the lanes, rolled up to the line, idled smoothly at the light, green light, give it gas to get moving and and it stalled. I tried to restart about 4 times while sitting at the intersection stop line with the traffic flowing past me on both sides of me. No Joy! I moved over to the sidewalk and tried a couple more times, nothing. I popped open the gas cap and closed it and it started and stumbled a little but smoothed out. I was able to get back out on the roadway and get back into the flow of the traffic. I chose to ride on the slower "side street" as opposed to main arterial I was on.

I stalled one more time, exactly the same situation. Idle at light, gas to accelerate, stall, sidewalk, open gas cap, stumble, idle, OK.

My ride was about 15 miles, in ~50F rain. I was dark too, as if that mattered.

[jprestonian]

When it stopped raining, was the behavior gone?

I would first check out some non-obvious things -- pull the seat bucket out, and make sure all the vacuum lines are connected tightly, and undamaged. Also check to make sure all hose clamps are tight. Air leaks can cause the behavior you describe, but so can other things... the air leaks/vacuum lines issue is pretty easy to check (even easier if you have some starting fluid handy that you can spray around in suspected intake manifold/hose leaks).
.

[ispud]

my guess is the darkness - my p250 hates to go out at night.  JK - I have no guess for what is causing your problem.  Does it happen when it's not raining?  Your gas source is reputable?  Ethanol??  I like to blame everything on Ethanol.  Please let us know when/if you get it figured out.

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[zombie]

It may have been coincidental w/ the rain. It sounds like the vent in the fuel cap is faulty. Perhaps water got into the well just below the cap? That would explain the way it started w/ a sputter, as the water would go to the bottom of the tank.

[ispud]

not biting on the darkness thing?

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[servant]

I have had the same experience three times. I have commuted 70 miles round  trip per day for the last 14 months, and believe me it rains daily here in central Florida during the summer months and I don't let rain stop me because I might get wet. One time during a torrential downpour I was sidelined 45 minutes before I got back going. In the beginning I would take the seat off and check the plug and everything else I could while I was on the side of the road, it was always a period of time to get back going. I believe it is water splashing it's way to the carb via air breather. I say that because I learned that if I rode on the crown of the highway as much as possible it was taking harder rains to experience going dead at the red light. It has never gone dead during non rain conditions. So now I time the red lights to go through on green as much as possible and pray to get home safely.

[ispud]

not fun - hope you get it figured out and fixed.

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[axy]

P250S has another interesting feature, the oil pressure indicator LED tends to flicker a bit when it is extremely wet outside.
I am not talking about regular rain or even when it's raining a lot, I am talking about washing the scoot with water under pressure, or extremely heavy rain.

I have noticed that the first day I took the scoot from the shop after buying it, it was raining like crazy and oil pressure LED started flickering. I came home and realized the next morning that the issue is moisture related, the indicator probe is probably a bit exposed to water that short circuits the thing.

This happens, once again, only when it is EXTREMELY wet around the engine.

Never had problems with stalling engine, neither on P250S or A125, even after heavy miniwash sessions...

[juice]

Can you rainproof a scooter?? by SeanOaloha . Check out this thread . Good luck .

[TechGuy]

I have not had a chance to work on it yet but this is what XLR8 suggested over at Modern Vespa.  I posted there to as another reular there has a P250 had stalled in the rain several weeks ago. I am regular there as it is a very active, positive forum and I enjoy the V crowd with my Kymco self.

Typically, rain or moisture will only affect things like ignition components like distributors or spark plug/coil wires that need replacing due to deterioration. I have never heard or read about about moisture causing a vapor lock. Vapor locks are almost always associated with poor venting of the gas tank.

If you want to perform a self-test, take a spray bottle of water and spray the spark plug wire while the engine is running and see what happens. We used to do this in the 60's when I worked at a garage, after school hours and on Saturdays. This method still works.

In a follow up:

TechGuy wrote:
XLR8,

Just to be sure I understand what you are saying. The insulation of the spark plug wire is deteriorated to the point where the water on the outside of the wire, is causing it to stall or stumble? I assume this is that the energy intended for the spark plug is leaking to the outside of the wire and then grounding out? No spark, no fire, no go... push.

It may sound like a dumb question to some. In my mind, the only dumb question is the one you didn't ask, when you had one.
Yes, that's it exactly. If this is your problem you can also run the engine in a dark room with a piece of metal (like a large wrench or screwdriver) next to the spark plug wire and it will arc from the wire to the metal if the insulation is leaking. (but, the easiest thing is to spray the wire with water from a bottle.......you'll know pretty quickly if that is the problem)

[zombie]

Both very good troubleshooting tips. I was mostly focusing on the gas cap aspect. There is a catch well around my fill cap, and if that filled w/ water I could see the Vapor lock happening. Let us know what you come up with.

[TechGuy]

I had wondered about the well at the fuel cap too but there is a dedicated breather tube for the fuel tank.  I wonder if the location of that tube is problematic and it is a combination of both factors. I think I will just replace the spark plug and cable as part of the on-going maintenace and look at where the tube runs to.

[zombie]

Look around some before you buy an OEM replacement. Just to give you an idea I will post a random replacement coil/ wire. why buy something that has failed twice?   http://cgi.ebay.co.uk/SYM-HONDA-KYMCO-PEUGEOT-PIAGGIO-GY6-Replacement-Coil_W0QQitemZ370095694523QQcmdZViewItemQQimsxq20091104?IMSfp=TL0911041710004r2509   I had wondered about the well at the fuel cap too but there is a dedicated breather tube for the fuel tank.  I wonder if the location of that tube is problematic and it is a combination of both factors. If you find that to be the case post back. 

[TechGuy]

I am not sure I understand you comment about something that has failed twice.  i have not replaced any of the parts in question but I ASSUMED the cable was a replaceable part but it looks (I have not confirmed) that it is a part of the coil assembly.  The part 3051A-LLJ3-E00  is $36.93 at Stadium ( my nearest local dealer closed, but I will check with the others not too far).

Is this true that that spark plug cable is permanently attached to the coil?

[Shaka]

I believe they are one piece.  However, it may "un-thread" from the coil like it does the plug cap, but I think it is one piece.