2007 Yamaha 50 hp 2 cycle never ran right from dealer

[99yam40]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

drop lower unit and rig up a water hose to pipe to power head and see if it will run OK that way.

I never like just changing impeller as the cup and wear plat need to be replaced also along with gaskets and o-rings

 

[Tnmtns]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

Ok will do.I took it apart again. I am getting fast at it and checked the impellar. I think maybe needs all the parts. Here is a picture. If it runs with the lower unit off and a hose then no doubt it is the pump correct?

It only seems to pick up water when we hold the muffs real tight. Ran it submerged in a tub and it never picked up at all.

 

[Tnmtns]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

Just wanted to say that my boat ran pretty good. It pumped water and the carb re-build helped. I still have some hesitation on throttle but not bad. I think it is a fuel mixture. Thanks to everyone for the help and do not hesitate to tear into something yourself.
By the way it was the muffs. My engine does not like them in the water it does great!!
Happy boating!

 

[99yam40]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

Good to hear you are back on the water.
Did you do the link and sync like manual says after reinstalling carbs?
Yamaha service manual is worth the money if you work on your own motor.
My C40TLRX has no problems with muffs, not sure why your 50 has problems with them

 

[Tnmtns]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

99yam40
Thank you for all your help. Caught a bunch of fish and found a pocket full of arrowheads. Good to be back out. Yeah I thought it strange on the muffs as well. I talked to my boat mech and he said the motor had to be about 6 inches below the input holes before it would draw. I never heard this but when I put it in the water at the ramp it worked like a champ. At least I know my lower unit is in good shape now with new impellers and fluid..
No I did not sync the carbs. I had one a little out of adjustment but adjust them with the linkage till they all closed at the same place and time. I guess it is back where it was as I still have that slight hesitation or bog down when hitting the throttle. If I do it fast it is ok. If I do it slow it can kill the engine.At least now it is not running on emergency choke. So I am thinking you are right I need to get the manual. That scares me as I got the manual for my Harley and have now torn it down and back together,,haha.
So just the dealers yamaha 50 book?

 

[99yam40]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

http://www.yamahapubs.com/
look the manual # up on here and punch that into your search engine to see what all comes up. Yes I prefer the Yamaha factory one.
With that hesitation ,I would check to see if timing is doing its thing like manual says and if the link and sync does not fix it then probably need to clean carbs better. Something is not right

 

[Tnmtns]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

Will do Yam may be after that next trip out though. The spotted bass are tearing up the spring lizards right now : )

 

[99yam40]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

Just remember if it is running lean on one or more cylinders it can hurt them

 

[Tnmtns]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

You know I never remember seeing any screws to adjust this when I tore it all apart. Is the adjustment done by jetting? Be nice to tinker with it on the water.

 

[99yam40]

Re: 2007 Yamaha 50 hp 2 cycle never ran right from dealer

only adjustment screws are the pilot screws, they are for adjusting amount of idle mixture that goes in.
The mix is controlled by air jets and fuel jets.

what did you set these at when you installed and adjusted the carbs?