2000 yamaha 50 hp 2-strokeproblems

[200racing]

im am out of ideas and need help.

from the top.
about two weeks ago i was out fishing. about dark we cranked up to head to the landing. about a minute into the trip the outboard started skipping a little and got worse quick. within 100yds i dropped of plane and it stalled it cranked but would immediately die. so i put my backup plugs in and it fired right up and ran good. back on plane no problem but within 400yds it died again. it would fire up and die within 3 seconds but i could keep it going with a little throttle in neutral. so i thought i might have trash in my carbs. i was able to drain 2 of the 3 carb bowls and it fired and we were able to putt back to landing a little faster than idle speed.

i have never put anything but no ethanol gas in my boat. before this trip i did purchase No E gas from a different station. that paired with it seeming to work after draing the bowls made believe i had a fuel issue. i purchased and installed a 10 micron fuel/water separator and siphoned my tank out and put fresh no E fuel from my usual store and treated it with marine stabil. i cleaned the carbs and installed all new line from the tank(10 gal plastic) to the outboard. i took it to the lake and it seemed to run good but minutes into my test run it started skipping and got worse. i circled back to the landing and came to a stop. it died but fired up and started to get on plane again but was running rough put died before getting there. it would crank with no hesitation and die within 3 seconds.

back home i figured a little trash had somehow got in the carbs again so i cleaned them again. went back to the lake and had a repeat of the previous trip. i did make 1 mistake. i took apart the fuel pump on the block to clean any trash out of it and i believed i damaged it as it later leaked in a test. i got a new one and installed it. another test run seem to be its self ran good for a mile or to then the old skip started again and this trip ended like the last one. cranking and dying within 3 seconds.

last things i have done is borrow a hanging gas bottle from a mechanic friend and hooked it up inline right before the new fuel pump eliminating the whole fuel system.with the foot in a barrel. let in idle as the engine warmed it started running rough.this test ended with it again cranking easy but dying within seconds. even with increased throttle in neutral.

the spark seems strong but quits when the engine starts dying. i had a friend mention the power pack and they can break down and act strange with heat. is there anyway to test or trouble shoot that.

and lastly i have not messed with this electronic thing on the side of the middle carb. can someone explain what it is and can it cause trouble. in my reading and research i have not figured out what it is or even seen it mentioned

web pic mine look nicer

 

[MDCrappie]

That's your primer for cold start.

 

[turbotodd]

Try your remote fuel tank again hooked directly to the carb inlet. Remove the line from the pump and feed it in there. While the engine is running (idle is fine) put a hose on the fuel pump outlet and the other end into a jar (free flow). See if your flow drops. If it does, then it's a fuel line or tank problem. If not, then it's most likely either carb or ignition. Ignition problems on these aren't common-at least I've not run into ignition issues (yet) nor have I heard too much of it. That power pack (CDI) is not cheap, so we'd probably want to rule everything else out before replacing it.

 

[200racing]

tried your test today the pump supplied more fuel then the engine burned. it took much longer for the symptoms to show up today. it did eventually start stalling at idle, but i could keep it running with throttle which seems to me to eliminate electrical. i cleaned the carbs one more time and believe i found trash in 1 of the carbs. so i have my fingers crossed and will try again tomorrow. how it got in there is mind boggling as much as i have cleaned flushed and replaced.

 

[turbotodd]

200racing » 03 Jul 2013, 19:44[/url]"]. i cleaned the carbs one more time and believe i found trash in 1 of the carbs. so i have my fingers crossed and will try again tomorrow. how it got in there is mind boggling as much as i have cleaned flushed and replaced.

Been there, done that!!! And embarassing. Took the GF out to the river a while back (cold 50° shallow river) and we were running up stream about 3/4 throttle (20 mph maybe). I've always taken pride in my rig...never had any problems. We were running fine and all at once it died. She was sitting on the front deck facing me. As it died immediately she came out of the boat and into the drink. About 3 feet deep at most so she just stood up. But it was COLD. Air temp in the 80's water temp in the high 40's low 50's. Started it back up and it would idle but wouldn't rev. Took the cowl off and put my hand over the intake and it'd rev then...figured the jet was plugged. Got it back home pulled carb and found a DOG TICK in the main jet. Just like yours, how on earth did it get in there? GF did not believe me.

 

[200racing]

turbotodd » 08 Jul 2013, 19:53[/url]"]

200racing » 03 Jul 2013, 19:44[/url]"]. i cleaned the carbs one more time and believe i found trash in 1 of the carbs. so i have my fingers crossed and will try again tomorrow. how it got in there is mind boggling as much as i have cleaned flushed and replaced.

Been there, done that!!! And embarassing. Took the GF out to the river a while back (cold 50° shallow river) and we were running up stream about 3/4 throttle (20 mph maybe). I've always taken pride in my rig...never had any problems. We were running fine and all at once it died. She was sitting on the front deck facing me. As it died immediately she came out of the boat and into the drink. About 3 feet deep at most so she just stood up. But it was COLD. Air temp in the 80's water temp in the high 40's low 50's. Started it back up and it would idle but wouldn't rev. Took the cowl off and put my hand over the intake and it'd rev then...figured the jet was plugged. Got it back home pulled carb and found a DOG TICK in the main jet. Just like yours, how on earth did it get in there? GF did not believe me.

you should have bought a lottery ticket

 

[200racing]

i have eliminated the fuel system. my carbs are spotless. running from a hanging bottle and catching the gas out of the pump it supplies i nice stream that more than matches what the engine is burning.

i had a friend who is a mechanic come over and look at it. we went through the electrical system. once it got warm it started its run and cut off routine we unplugged a thermal censor and it would run much better not perfect but better. part #12 on this diagram.
https://www.**********/parts/search/Yamaha/Outboard/2000/C40TLRY/ELECTRICAL 1/parts.html

seems like more than coincidence to me but i want to be sure.
using the ohm feature on a voltmeter you can tell when it gets warm it completes a circuit.

does anyone know what temp this circuit is supposed to operate at?
its part # 6H4-82560-00-00