Starting Problems!!

[Sea18Craft]

Hoping someone can help.... Have a 2004 Yamaha 150 (Carbed) and having starting problems after running the boat for some time and I do not have the issue when the motor is cold (at the ramp or the house). It takes a while to turn over, here are some parts that were replaced recently: fuel filter, plugs, adjusted the idle to 800, new batteries, and the fuel looks good. Please let me know if you have any suggestions. Thanks

[Bushwacker]

Have you checked compression? (With motor warm and WOT.) Also pump primer bulb to make sure carb float bowls are full and that you don't have a problem with vapor lock (more likely with E-10 gas!) Problem is most likely in ignition system. Coils expand when they get hot, so if there are breaks in the windings, the coil will work fine when cold, but output voltage will drop when coil gets hot and expands, opening up cracks in the windings!

Suggest you make up a spark checker . . . get a PVC cap, maybe 3-4" ID, and get seven 1/4-20 SS screws about 3"-3.5" long, a ~12" length of wire, an alligator clip and a 1/4" ring terminal. Attach alligator clip to one end of wire and a 1/4" ring terminal on other end; drill 1 hole in center of cap, tap with 1/4-20 thread and install 1 screw into it with ring terminal/wire under head of center screw on outside of cap. This will be a ground wire. Drill 6 more radial holes around outside of cap, spaced every 60 degrees, and tap with 1/4-20 threads. Spray inside of cap with flat black paint. Cut the heads off 6 screws and install in sides of cap; use a 7/16 nut, which fits a 1/4-20 screw, to set a 7/16 gap between the center screw and each of the 6 radial screws, which should extend ~1 1/2" outside of cap.

To check entire ignition system, clip ground wire to engine block, pull all wires off plugs and attach each one to a stud on outside of cap. Hook up flushing attachment and turn on water. How have someone crank motor and watch to see if a bright blue spark jumps from each of the 6 studs to center ground screw. With healthy coils and power pack, the spark will jump a 1/2" gap, so if the spark on any of the 6 studs won't jump a 7/16" gap, you've got a problem on that coil and/or power pack! I've found bad coils and power packs with this tool. If you don't get ANY sparks, it could be a problem with the sensor coils in the stator assembly which trigger the ignition system, or a problem with key switch.

Hope this helps! Keep us posted on what you find!

[Sea18Craft]

Thank you for the detailed advice. I will let you know my findings this weekend.

[Sea18Craft]

Bushwacker,
So I took your advice and checked the ignition system. Everything checked out so I can check that off the list. I replaced the primer bulb as well. Prepped her to take out this past Saturday Friday night, ran great at the house, dropped her in the water and now had a challenge starting her cold. Finally got her started after 4-5 cranks (choked) and she ran great. Went trolling for a few hours and went to Elliot for an hour and bamn had problems starting again. I'm thinking the carbs, any thoughts or suggestions? Thanks

[gofastsandman]

Originally Posted by Sea18Craft

Bushwacker,
So I took your advice and checked the ignition system. Everything checked out so I can check that off the list. I replaced the primer bulb as well. Prepped her to take out this past Saturday Friday night, ran great at the house, dropped her in the water and now had a challenge starting her cold. Finally got her started after 4-5 cranks (choked) and she ran great. Went trolling for a few hours and went to Elliot for an hour and bamn had problems starting again. I'm thinking the carbs, any thoughts or suggestions? Thanks

Still think it is ignition. Put some premix in a spray bottle. Run till hot in the water. Try starting. If no go shoot fuel into open butterflies. What happens?

[Bushwacker]

Originally Posted by Sea18Craft

Bushwacker,
So I took your advice and checked the ignition system. Everything checked out so I can check that off the list. I replaced the primer bulb as well. Prepped her to take out this past Saturday Friday night, ran great at the house, dropped her in the water and now had a challenge starting her cold. Finally got her started after 4-5 cranks (choked) and she ran great. Went trolling for a few hours and went to Elliot for an hour and bamn had problems starting again. I'm thinking the carbs, any thoughts or suggestions? Thanks

A hot starting problem smells like ignition to me! Nothing much changes in the carbs when they get hot, although I suppose vapor lock could be a problem if you're running E-10 "Moonshine"gas, but that's unlikely! If you have a coil (either sensor coil or ignition coil) with cracks in the windings, it'll work fine when it's cold, but when it heats up, the coil expands, the cracks in the windings open up, and then the coil doesn't work!

I had an old '58 Johnson V-4 with a magneto system with a bad coil in it. It started fine when cold and would even run fine at high speed when hot because the magneto generated so much voltage at high speed that the cracks didn't matter! But as soon as you slowed down, the magneto output dropped, so it would quit and refuse to start till it cooled off! The guy who towed me back to the dock had a mid-60's Evinrude V-4 with conventional battery powered single coil & distributor/breaker point system, and said he was several miles offshore fishing in the gulf stream one day when his quit! They packed ice around the coil and got it going again and kept ice on it till they got back in!

So if you made up that spark checker, keep it on board, and use it the next time you run into a hot start problem to see if you're still getting a spark! Don't know much about Yamaha's, but if it's a 2-stroke V-6, I think they basically just copied the OMC design. It might still run (badly) if only one ignition coil is bad, but if it's either a bad sensor or charge coil in the stator assembly under the flywheel, you probably wouldn't see a spark on any cylinder. Maybe the ice bath treatment would help that!

[Sea18Craft]

Good morning guys. Took her out yesterday and had starting issues again. At the house she starts after one crank. At the ramp it takes four to five cranks. Now in the water whether hot or cold she takes a few cranks. It seems like there is not enough fuel getting to the motor. The first thing I replaced was the primer bulb so I can check that one off the list. This is starting to become extremely annoying, please let me know your thoughts. Thanks

[martin]

Run her on a fresh portable tank of gas.. It could be water in fuel or trash moving around if you hook a vacuum gage up to it and see what it is when it fails, that would help.. Then again if the primer bulb is not collapsed then your vac is probably good. Change out water separator

[red20]

I had the same issue. Chased the ignition side for a while. I replaced the fuel connection at the motor and problem went away. I think I was getting air, the one i replaced was an aftermarket connection not the OEM. Simple fix and have had no issues for over a year.

here is the part number

FUEL PIPE JOINT COMP. 2

6E5-24305-02-00