Won't run after open throttle operation

[kahoona]

I have a Yamaha '90 130 hp outboard. The carbs were recently rebuilt. The plugs are new. The boat has not been used for at least 2 months, possibly a few months. The tank had perhaps 20 gallons of fuel in it when I bought the boat I added 1/2 of a pint of Starbrite water remover and 17 gal of fresh gas to the tank. I took the motor off of the boat for 3 weeks while I replaced the transome. It was suspended from its lifting ring on top for the entire time. All wireing ect was disconnected while it was off. The motor started well and runs well. The idle is smoothe and it sounds fine. It runs well idleing out through the harbor no wake zone and runs very well at larger throttle openings. It seems to be fine for any ammount of time. Once the throttle has been open for more than a few minutes The motor will quit if the throttle is closed. It will not restart normaly for a long time after that. Ether spray will revive it although it will continue to stall at idle untill given a rest of an hour or more. It does not seem to be overheating at all. After the first occurence I changed the spin on water seperator/filter and cleaned the screen in the small filter. Both seemed to have clean gas in them. I did not notice any water in the seperator. When I started the motor after changing the filters white smoke (not blue) came out for a few minutes. That was the only time I have seen white smoke from it. I took it out and once again it ran great through the 20 minute no wake zone the blasted about offshore for half and hour and then quit when I throttled back for the no wake zone. Anybody have any ideas?

[jb123]

i wouldnt spray ether in MY motors....i would clean carbs again, check/replace fuel lines, replace seperator,remove quick disconnect at motor and run line direct and check fuel pumps. is your buzzer working correctly????

[beaker]

I had a similar problem on my engine. Turns out I had some build up in the fuel pumps that was keeping them from providing enough flow at low RPMs especially after a hard run. They were very easy to inspect and if you have the manual, very simple to dissasemble and reassemble in an hour. Bottom line is, if there is junk in the fuel pumps, it will either restrict the flow, or keep sending particles to the carbs to clog them up.

Good luck.

[kahoona]

OK guys
Thanks for the help.I will start at the fuel lines and filter seperator and clean through the pumps and the carbs and see if it improves. I connected the motor to a can of clean new fuel and there was some improvement but not a lot. That would seem to confirm your diagnosis. I will get a manual first. I also notice that the enrichment switch on the console does nothing. If it were stuckin the on positon would that cause this kind of problem? Can I test that by unpluging the wire?
Thanks
Kahoona

[Ken]

Kahoona,
The choke switch on the console when engaged (and working) sends 12 volts to the choke solenoid that is mounted at the top of the carbs. The choke solenoid then pulls in the linkage that closes the choke butterfly valves in the throats of the carbs. If the choke was always engaged, then the motor would start, but would not run very well because of the rich mixture and would smoke an excessive amount.
Good luck,
Ken K

[kahoona]

Thanks to all. When I removed the fuel pump to clean it fuel poured out from behind it indicating a pinhole leak in the diaphram and therfore way too much fuel getting in and flooding the engine after full throttle operaation. I replaced the pump because it was cheaper than the parts needed to overhaul it. It runs great now. The choke lever on the dash and its solenoid both worked but the circlip that held the linkage in to the carb was missing. Easy to fix! Thanks again.