2003 Yamaha 50 hp 2 stroke problem

[Bozol]

Re: 2003 Yamaha 50 hp 2 stroke problem

Im having an electrical problem with my 90 2008fs, sounds kind of like something you described. The other day went for a ride and turned the motor off but didn't remove the key. Went to start the engine and no luck, just a clicking in the engine. Changed the battery, made sure the trim was working at the motor (wanted to eliminate as many potential problems as possible) and when in gear the battery died when I hit the trim button - must be a short eh? Wondering if anybody else has had this problem. It's been going on for a while but not this obvious. Before if I left the key in the ignition overnight or for a while the battery would die, but I didn't ever notice a connection with the trim. Any thoughts from everybody would be appreciated.

 

[Toddboat]

Re: 2003 Yamaha 50 hp 2 stroke problem

Feel the metal part of the throttle control and the metal part at the base of the steering wheel while turning the key to see if it tingles. Mine does that. If I leave the positive battery lead connected, the battery will die in a couple days. But my mechanic told me that that 12 volt leak would not have anything to do with the motor not running right. My motor always tries to turn over. I don't ever just have the click that you have. I think you need to fully charge your battery and always disconnect the positive lead whenever it's not in use until you track down your leak.

 

[Bozol]

Re: 2003 Yamaha 50 hp 2 stroke problem

I hate to say this but think the problem was found - dirty leads. An electrician swore it wasn't because 'I've seen dirtier leads start cars,, generators etc' but we cleaned'm up and seems to be working ok. Will take the boat out soon and if it's a different problem will be posting again. we had wires out, meters testing, fuses checked...KISS was never so evident!

 

[Toddboat]

Re: 2003 Yamaha 50 hp 2 stroke problem

Partial success! The motor started right up today instantly, and ran at all speeds and did not stall in idle. So I guess it really was clogged carbs after all. The reason I say "partial success" is because I have not tested it in the water yet. I can't put it in the water until the propshaft oil seals arrive and I replace them and fill the gearcase with oil. I'm hopeful that the boat will run well considering in the three years that I've owned it, it has never started up and ran that smoothly before. Once you build up confidence in working with your carbs, cleaning them is actually a very easy thing to do. It will now be part of my standard maintenance thing, as will be adding fuel stabilizer each time I add fuel.
I think my fuel lines may be deteriorating from the inside because I see black specs in the carbs that were not there after cleaning. The fuel lines are the only place this can be coming from at this point, so I plan on replacing them shortly.
Am I correct that you just buy a certain length of the correct diameter of fuel line and cut it to match the pieces that you're replacing? You don't have to buy individual pieces, right?

 

[99yam40]

Re: 2003 Yamaha 50 hp 2 stroke problem

Yamaha sells preformed lines for around the carbs on motor, keeps from lines kinking, but you can try to do it any way you want

 

[Toddboat]

Re: 2003 Yamaha 50 hp 2 stroke problem

Thanks 99Yam40, I've noticed that some of the smaller lines have permanent curves in them, which may be hard to reproduce. I'll probably replace all of the straight pieces and leave the small curved pieces in place. Thanks again, and thanks for steering me back towards troubleshooting on the fuel side. Your original idea of what might be wrong turned out to be exactly what the problem was. I know now that I understand the circuitry of my carbs how to troubleshoot them very easily. You just remove or disable the float and hook the fuel line back up to the carb. Then prime the bulb and watch the idle and low speed holes at the top of the carb. If fuel is coming through them, there's no clog. With the float in place, there's no way to troubleshoot this easily. If I had it to do over, I would have this fixed in under an hour!

 

[99yam40]

Re: 2003 Yamaha 50 hp 2 stroke problem

I see not reason to go through all of that, just pull apart and clean carbs properly and link and sync when putting back on.
Good idea to clean/flush lines and pump to make sure more stuff does not hit the cleaned carbs as soon as fireing back up

 

[Toddboat]

Re: 2003 Yamaha 50 hp 2 stroke problem

Now I can clean them properly because I know where the circuitry is. I guess my method of removing the float is more of a troubleshooting one. It could come in handy someday when I have a different motor with carbs that I'm not familiar with. At least for these Keihen carbs, I know exactly where to shoot the carb cleaner. Too bad these circuits aren't illustrated in the manual. I suppose that's because Yamaha doesn't make the carbs and probably uses more than one brand/type for the same model of outboard at times.

 

[Toddboat]

Re: 2003 Yamaha 50 hp 2 stroke problem

Oops! I mistook the oil dripping out of the prop for LU oil because I had recently changed it and thought I had disturbed the seal. It adds up now that the seal seemed to have nothing wrong with it when I removed it. The oil was actually from the thru-prop exhaust. It was black and sooty, as opposed to the light brown LU oil I had put in. The LU oil should still be light brown considering I haven't run the boat since changing it. I never had oil coming from the prop before through the exhaust. Would this be from running it on premix with the oil pump disabled, or from running Seafoam through the motor? This may be the first time the motor has been decarbonized since new. I am not the original owner, so I wouldn't know. If it's from the Seafoam as I expect, then wow that stuff really works. The new prop shaft oil seals arrive Monday, at which point I'll be able to sea trial the boat for the first time since I got it running well on muffs. Hope it has power in the water!