Yamaha 115 hp Won't stop running after key is off

[kcjones1504]

Have adj the air flow and now the eng won't stop running. Have to cut gas off to get it to stop or it stops after a few mins. To much fuel to carbs?

Thanks Kc

[rodbolt17]

put the tools down.
back away slowly.
get a basic understanding of a basic ADI/CDI spark ign engine.
test the ground path from the block to the keyswitch,black wire, then test the white wire from the keyswitch to the CDI.
has NOTHING do do with carbs.

[kcjones1504]

K check both their fine. No nicks no dings messed with air flow on carbs and it don't stay on like i said anymore. HMM what else. Besides it runs in the drive way but not at the lake. Does it not like lake water>? lol jk

[rodbolt17]

trust me its NOT an air fuel adjustment and without a model number yours may not even have it.
test spark, test compression fix the ENTIRE fuel system not just a patch at a time.
the kill circuit can only be tested with an Ohm meter.

[kcjones1504]

Thank you robbolt for you help. I have a major prob. Mabe you can help. I had a guy who said he knew what he was doing and had worked on boats for over 20 years so I let him work on my yamaha 115 6el5. 1986 modle. He rebuilt the carbs but when I put it in the water she ran fine for about 10 mins then back fired and staled, I had him come back over and fix the problem and he got it running in the drive but when I put it in the water it won't start. The boat was running just fine last year. I know it was running after the rebuild but then he was messing with the screw for the air flow, And this is where I am I can start it now and it turns off fine I believe you when you said check the wireing with I did and only thing I found was a croshion problem on the pasitive side wich i cleaned up and reconnected with wire connector clips that you screw togeather, I,m not sure where to go from here on how to reset the carb screws, The problem is i have spent to over 300. on a carb kit and his work wich on something that never got fixed. Im lost. If you wouldn't mind helping I would be greatfull to you. the eng does not get hot, and their new spark plugs and new gas tank, hose and filter to carbs.
Thanks again KC

Omaha Neb

[99yam40]

A Yamaha service manual for your motor would go a long way to helping you right now. Just saying it would be a good investment if you plan on working on it yourself. Not sure why anyone would work on something without a manual. These motors are not just simple motors of old

[rodbolt17]

like I said.
at this point, test spark.
test compression.
if both pass make sure the timer base moves with the magneto control arm.
if all the above work remove the fuel pump lines and carbs or dissasembly,cleaning and inspection.
google a home made spark tester.
myself and a few others have posted how to make one.
spark gap on your motor for testing is 7/16ths.

[kcjones1504]

ROdbolt

want to thank you again for your responce. The spark plugs are new and have been tested and are gaped right, I got the eng running and she sounds real good better then befor I got it. She starts every time no gas comeing out of the carb. She will turn off every time now and the lower carb sounds fine now No back fire no cutting out. Although Im no out board mech> I have basic knowlage of the motor and carbs. All I have left is the eng woun't go on plan wants to die out if i give her to much gas.Sounds like upper carb will be rebuilt but allso sounds as if the carb is starving for air when I try to come off plan, Tring to figure out how to set the upper carbs so they run like factory.

Once again thank for your help as I am looking at every thing you tell me to look at and check, I am a low votage tech and know how to run and test wires, Thanks again KC Omaha Neb