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2007 Yamaha 25 ESH 2-stroke “Bogging”

P

Paulw71730

New member
Low hours on this outboard, fuel is fresh ethanol free, not ran in over a year except in yard on muffs. Only part ever changed was water pump. Never any issues until today on the water.
Problem - starts fine but runs rough at idle, Boggs down when trying to accelerate (kinda like pulling out the choke on a warmed up motor). Stays bogged down with throttle wide open but after 15-20 seconds it starts picking up and will run 3/4 to wide open speed perfectly for long as you want. Then same thing when stopping and starting over. Where should I start?
I’ve searched several pages on the forum but can’t find this symptom. Thanks in advance.
 
I'm pretty sure you have a low speed fuel delivery problem. Motor isn't getting enough gas at idle and it really struggles to keep the motor running until the main jet takes over. You can start by adjusting the idle mixture screw. It's #16 on the picture in the link I've attached. There is a plastic cap over the head of the screw that only allows you turn it a little bit. Counter clockwise turns increase fuel flow. If you adjust it out, but it helps a little but not enough, it's time to remove the carb, order a carb kit and get to work cleaning out all the passages really good and spraying compressed air through all the little openings. If you don't have access to a compressor, a can or carb cleaner with the small "straw" on it will work pretty good too.
 
Yes sir, pretty sure I saw that mixture screw today. I’ll adjust it first and if no help I’ll go to work on the carb. Thank you very much.
 
Oldsaltydog said:
I'm pretty sure you have a low speed fuel delivery problem. Motor isn't getting enough gas at idle and it really struggles to keep the motor running until the main jet takes over. You can start by adjusting the idle mixture screw. It's #16 on the picture in the link I've attached. There is a plastic cap over the head of the screw that only allows you turn it a little bit. Counter clockwise turns increase fuel flow. If you adjust it out, but it helps a little but not enough, it's time to remove the carb, order a carb kit and get to work cleaning out all the passages really good and spraying compressed air through all the little openings. If you don't have access to a compressor, a can or carb cleaner with the small "straw" on it will work pretty good too.
Click to expand...
Update: adjusted idle mixture screw on both carbs counterclockwise to max. Helped a little but not enough. I’m ordering a kit. Thanks.
 
Oldsaltydog said:
I'm pretty sure you have a low speed fuel delivery problem. Motor isn't getting enough gas at idle and it really struggles to keep the motor running until the main jet takes over. You can start by adjusting the idle mixture screw. It's #16 on the picture in the link I've attached. There is a plastic cap over the head of the screw that only allows you turn it a little bit. Counter clockwise turns increase fuel flow. If you adjust it out, but it helps a little but not enough, it's time to remove the carb, order a carb kit and get to work cleaning out all the passages really good and spraying compressed air through all the little openings. If you don't have access to a compressor, a can or carb cleaner with the small "straw" on it will work pretty good too.
Click to expand...
This little fleck of rubber was in the idle jet passage. Fell out when pulling out jet. Installed kit and motor runs like a top. Thanks Salty dog!
 
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