1992 K75 caught in the rain, lives, dies, lives, no power

[DieselHippie]

OK I'm getting to the end of my rope with this thing. Sunday I attempted to drive to the beach but about half way there I got caught in the rain. I had been driving for maybe 2 minutes in the rain before I noticed a substantial loss of power which and then nothing, so I coasted down a side road and stopped.
Background on the bike, rolling project, got it with a little cosmetic burn damage and stripped it down as much as I could. I have gone through almost all the common neglected maintenance points.
Mechanical wise she is stripped down cafe style, ECU mounted to underneath seat, air box delete, most covers and plastics removed.
Starting attempts #1 stater relay stuck for a little, annoying, but gave me an excuse to hit the bike   :2thumbup:
-Attempt #2 Found ECU had taken water, borrowed a hair dryer from a nearby house and dried it out as best I could, still no fire but gas was working its way out the exhaust.
-#3 unplugged the fuel pump and Cranked the throttle back and got it to fire back up. Would not idle, but would stay alive with a little throttle. *Note as soon as I plugged in the fuel pump it would die.

I tried to limp the closet gas station but only made it a quarter mile before she gave out completely. :falldown: Long story short after a little hitch hiking, a few phone calls, and a few hours of driving back and forth I had the bike home.

Fastforward a few days tore her back down for the 1000th time.
-Attempt #4  After cleaning her up, waterproofing the ECU with silicone, removing the fuel filter, and fiddling with the fuel pump plug I got her to fire and run.  :riding: everything seemed ok, I didn't have time to do a thorough test run so I drove it down the street to work.
-Attempt #5 Once I got off work she fired right up but has little to no power so I limped home, throttle pinned doing ~5mph...
-Attempt #6 This morning I thought the TPS might be at fault so I unplugged it while she was idleing. I noticed a small change in the idle but still rides the same, no power.  :musicboohoo:

Hall Sensor? I'm thinking a big carb and a turbo will be a lot easier at this point....

[Inge K.]

, still no fire but gas was working its way out the exhaust.
-#3 unplugged the fuel pump and Cranked the throttle back and got it to fire back up. Would not idle, but would stay alive with a little throttle. *Note as soon as I plugged in the fuel pump it would die.

Sounds like you have a all to much rich mix, check the water temp sensor.
Disconnect the injection ECU, measure between contact #10 and 13 (13 is the frontmost contact).
You should measure ~2,2 Kohm at 25^oC.
To high resistance or a open circuit gives to rich mix.

[Scott_]

How's the condition of the vacuum line for the fuel pressure regulator, and/or other vacuum leaks.

[Motorhobo]

I rode 10 years in Seattle where if you're not prepared to ride in the rain, you don't ride at all. Never in 10 years did the rain no matter how brutal (I.e. boots filling up to the brim with water etc) affect the performance of my brick. So -- if you still have the problem after it dried out and have discounted the possibility that water flooded your fuel tank due to a leaky cap, I wouldn't be looking to water as the cause.

That said...it might be a long shot but if you think theres a connection between the rain and your brick crapping out maybe you should drain the tank, check the fuel filter and watch Chris Harris' youtube video on fuel filler cap maintenance/rebuild.

[DieselHippie]

OK Temp sensor reads at 2.3 and all hoses are good.

I poked around a little more with the MAFS and almost all my readings where off in reference to this
>>>>  http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/bike-wont-start1.htm  <<<<

Connections look fine, so what am I looking at shot MAFS? Can I open it up and fiddle with it without breaking it?

Thanks for the responses

[ReneZ]

You could read up on it on the same site or here. Or you could swap it out with another one you know is good. :-)