First off im new to outboards and dont have much experience with motors besides help from youtube and the internet
Not sure if the older mariner are considered to be yamaha but it says mariner so besides that, I recently bought this 2stroke 50hp outboard for a small fishing boat from a local motorsports. Was told it runs great just needed new steering cable so i knew the motor hasnt been on the water in a long time.
Took a little bit to get it started but after changing the spark plugs and now after idling it with muffs and running some seafoam through it, it starts right up no problem idles great.
Problem-
I took it to the water and launched the boat, started right up and let it warm up and idle. I started off slow and progressively ramped it up over time and started off great then after 2-3 minutes the motor bogged down to about 1/5 of what it can do even with the throttle almost pinned. So with the throttle almost maxed out it would sometimes ramp up for a second or 2 then die back down. The motor never stalls, it just wont ramp up. I put it back in neutral then would try to slowly ramp up the throttle and no matter how much i give it, the engine boggs down and only reaches 1/5 of its power, then like i said at some points it will randomly ramp up then quickly go back so I would keep it in neutral
What ive done so far-
Originally ran seafoam through the carbs for cleaning purposes before launching it, I replaced the 6gallon gas tank(old one was glued together) with fresh gas, replaced the gas line from the tank to motor including the primer bulb, changed the spark plugs. Ive checked the gas flow to the carbs and that seems to
be fine as well, plenty of gas to the carbs when i squeeze the primer.
So after changing all the things listed above, I launched the boat again and everything worked as should, I stayed close and went out for 15-20 minutes, everything seemed great. Put the boat away, launched it the next day and boom, same issue, boat ran for 2-3 minutes then would bog down to 1/5 capacity even with throttle pinned. So im running out of ideas and hoping you guys can help a guy in need of help that doesnt know much about outboards. Open to any and all ideas! Thanks.
Not sure if the older mariner are considered to be yamaha but it says mariner so besides that, I recently bought this 2stroke 50hp outboard for a small fishing boat from a local motorsports. Was told it runs great just needed new steering cable so i knew the motor hasnt been on the water in a long time.
Took a little bit to get it started but after changing the spark plugs and now after idling it with muffs and running some seafoam through it, it starts right up no problem idles great.
Problem-
I took it to the water and launched the boat, started right up and let it warm up and idle. I started off slow and progressively ramped it up over time and started off great then after 2-3 minutes the motor bogged down to about 1/5 of what it can do even with the throttle almost pinned. So with the throttle almost maxed out it would sometimes ramp up for a second or 2 then die back down. The motor never stalls, it just wont ramp up. I put it back in neutral then would try to slowly ramp up the throttle and no matter how much i give it, the engine boggs down and only reaches 1/5 of its power, then like i said at some points it will randomly ramp up then quickly go back so I would keep it in neutral
What ive done so far-
Originally ran seafoam through the carbs for cleaning purposes before launching it, I replaced the 6gallon gas tank(old one was glued together) with fresh gas, replaced the gas line from the tank to motor including the primer bulb, changed the spark plugs. Ive checked the gas flow to the carbs and that seems to
be fine as well, plenty of gas to the carbs when i squeeze the primer.
So after changing all the things listed above, I launched the boat again and everything worked as should, I stayed close and went out for 15-20 minutes, everything seemed great. Put the boat away, launched it the next day and boom, same issue, boat ran for 2-3 minutes then would bog down to 1/5 capacity even with throttle pinned. So im running out of ideas and hoping you guys can help a guy in need of help that doesnt know much about outboards. Open to any and all ideas! Thanks.
Last edited:
