Yamaha F50 4-stroke 2003 carb version, idle probs

[CodHunter]

Hi folks,
thank you all for your posts reg. problems with starting, prime start, idle probs...
I fixed my problem today, I could do that due to precise information I took from many posts.

Last week I tried to start my motor after winter season, it started immediately but died after about 30 sec.
Then, I read everything about similar problems in this forum.
I did the following:
Replaced spark plugs - no success
Cleaned filter and water separator - found some dirt and some little water
Measured power supply at prime start elements - good
Disconnected prime start elements from power supply - motor started good and idle for three minutes!!, but rough and low idle, finally died again.
This afternoon I removed all four carbs, opened them, cleaned them, found some dirt in the float housings, traces of water and ... corrosion on the brass parts inside the carbs including the main nozzle. Removed dirt and corrosion, blew air through all openings, reassembled all parts and started the motor ...
Ah, what a success, engine ran like heaven, problems gone.
If anyone needs, I took pics from the corroded parts.
Thanks again
Mike

 

[#11]

Re: Yamaha F50 4-stroke 2003 carb version, idle probs

Hi folks,
thank you all for your posts reg. problems with starting, prime start, idle probs...
I fixed my problem today, I could do that due to precise information I took from many posts.

Last week I tried to start my motor after winter season, it started immediately but died after about 30 sec.
Then, I read everything about similar problems in this forum.
I did the following:
Replaced spark plugs - no success
Cleaned filter and water separator - found some dirt and some little water
Measured power supply at prime start elements - good
Disconnected prime start elements from power supply - motor started good and idle for three minutes!!, but rough and low idle, finally died again.
This afternoon I removed all four carbs, opened them, cleaned them, found some dirt in the float housings, traces of water and ... corrosion on the brass parts inside the carbs including the main nozzle. Removed dirt and corrosion, blew air through all openings, reassembled all parts and started the motor ...
Ah, what a success, engine ran like heaven, problems gone.
If anyone needs, I took pics from the corroded parts.
Thanks again
Mike

Hi Mike!
Are having similar problems with my Yamaha after winter and I?m about to dismantle the carbs this weekend, all tips and tricks is helpful and if you have pics to send I would be greatful.
I have allreday had the bottom carb removed ones due to that it got stuck, found som corrosion on the main axle with could be fixed with som minor polishing of the axle and honing of the holes. I?m suspecting that the carbs needs a big cleanout and some tinkering in order for the engine to work properly, now it is going down on 3cyl sometimes and it sounds rought on idle.

Best regards,
Ola from Sweden