2007 Yamaha 50 hp 2 cycle never ran right from dealer

[Tnmtns]

Thanks everyone
I have a 2007 50 hp yamaha 2 cycle on a G-3 boat camo duck boat. From the very beginning I used non ethanol gas. Would start idle and upon acceleration bog down. I changed plugs filters and took it back to the dealer several times. They suggested a fuel additive... No avail. This season took it out and it would only run on emergency choke. Came home pulled plugs drained the carb bowls and the filter. Fuel filter looked like it has small bits the size of Graphite in it. I decided to pull the internal gas tank out and run it thru a cloth. Very little debri. I tried sea foam to no avail on carbs. I am thinking that I need to clean or rebuild the carbs but have no faith in the place I bought it. Bottom drain plug looked all shellacked on bottom carb. It dumpe gas when cranked but the float seems to have become un stuck now.
Ok so I guess I need to pull the carbs. I think I can do this is it hard and is there a link on line about doing it and cleaning the jets? Have read topics on here for some time and feel this is a common problem with these engines. My initial research said they were bullet proof. This does not work and we will see how they handle a bullet haha.
Thanks all for any help crappie season has drifted by already.
TnMtns

 

[99yam40]

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

How many years have you owned this motor that has never run properly?
Is it a used boat and motor?

Do you have a 10 micron fuel filter/water separator in line to motor?
If not get one,built in tanks can be a pain

The carbs are simple .
Pull them all as a group and the disassemble one at a time to clean and put back together so you do not mix up any parts.
After reinstalling do the link and sync like manual states

 

[1080tommy1]

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

Great advice. These carbs are very easy to remove and take apart. I had the exact same problem when I bought my 40hp. The thing was running on two cylinders and would only idle with the emergency fuel valve in the first position. I took all three carbs off and took each one apart. Sounds like at some point there was water in the gas and the jets are clogged. My middle carb had the main needle completely stuck closed and it took some time and solvent to free up. After I did this I just put the carbs back on exactly how they came of and the motor runs flawlessly now. Good luck and don't be affraid to take them off and clean them. Just make sure they go back on exactly how they came off and when you split the carbs look for residue clogging needles and jets and also make sure you put the carb halves together properly.

 

[Tnmtns]

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

The boat was brand new when I bought it. It does not have the 10 micron filter on it. But I will put one on. It missed at throttle from the beginning and I took it back several times. They said it was the gas. Very poor service. I crank it often and keep good fuel in it. This year however the battery was dead and when I replaced it the bottom Carb float was stuck and dumping fuel. I got it unstuck and it will now only run in emergency choke. Just downloaded an exploded view of the carbs and picked up several cans of carb cleaner.
Thanks for the votes of confidence. I am going to give it a try after i reinstall the inboard tank. I will have to get the info to link and sync them.

 

[Tnmtns]

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

Carbs are now off.

 

[Tnmtns]

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

Trying to figure out how the linkage that ties the 3 carbs together comes off??

 

[99yam40]

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

just pops off

 

[Tnmtns]

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

Thanks 99yam40. Was scared to force it. Popped off like you said have it all soaking now.

 

[99yam40]

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

Not sure about procedure on that new of a motor but here is a thread where Rodbolt gave info for my C40 99 model , maybe it will help.
But it would be best if you picked up a Yamaha service manual for your motor

http://forums.iboats.com/showthread.php?t=366637

 

[1080tommy1]

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

I did not link and sync my carbs after removing them initially and the motor ran fine. I did get a tach to verify idle speed and I was right on the money. I am going to be fine tuning my prop this or next week and will probably do the link and sync just so I know how to set the carbs correctly but since cleaning the carbs, the motor has run flawlessly. I did exactly what you are doing. I removed the carbs and soaked them. Then, just cleaned all jets and made sure the needles were free. Good luck.

 

[99yam40]

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

I was told to look at those 3 cylinder motors as 3 one cylinder motors tied together by the crank, If one carb throttle plate is not in sync with any of the others you end up with them fighting each other.
When bolting back on there are no line up pins, just bolts and holes and you can have them off slightly from where they were before. With the linkage still adjusted the way it was before, it can be off a little.
Best to adjust every time you reinstall just to be sure

 

[Tnmtns]

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

I pulled all the jets that would come out and cleaned everything well. I also disassembled the diaphragm and stuff where the emergency choke is. Cleaned it all. Just a little shellacking over all. The little needle valve that is like a plumb bob off the float was a little dark on one. If the rain lets up will try to install everything tomorrow evening. Tank is clean lines have been flushed and filters cleaned. Other than the trash in the filter never saw anything that really said that this is what is wrong.
Thanks for all the help and hopefully everything will line back up on installation. Going to take it slow one at a time and maybe it will be ok. I will post my results. here they are ready to go back in

 

[Tnmtns]

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

I pulled all the jets that would come out and cleaned everything well. I also disassembled the diaphragm and stuff where the emergency choke is. Cleaned it all. Just a little shellacking over all. The little needle valve that is like a plumb bob off the float was a little dark on one. If the rain lets up will try to install everything tomorrow evening. Tank is clean lines have been flushed and filters cleaned. Other than the trash in the filter never saw anything that really said that this is what is wrong.
Thanks for all the help and hopefully everything will line back up on installation. Going to take it slow one at a time and maybe it will be ok. I will post my results. here they are ready to go back in View attachment 141684

Ok I finally got new gas in and got it started. Had the hose to it. Ran rough at first then went to a nice idle. I noticed the water was not pumping out. Then it started to pump out and the water was very very hot. The alarm sounded and I let it run for a second or so and it stayed hot but was pumping. The alarm did not shut off so I shut the boat off.....

Any idea was this could be?? Did it just take to long to pick up on the water? I sure do not want to damage the engine.
Thanks everyone for you help.
TnMtns

 

[99yam40]

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

when was the last time the stats and water pump replaced?

 

[Tnmtns]

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

Hey 99yam40
I have not replaced either before. It would seem strange that after just cleaning the carbs this would happen. I have a new hose adapter that this is the first time I have used. The engine is running well and it is picking up the water after about 30 seconds but the water is very hot and the alarm is going off. It just did it again after I let is all cool down. I may try my old hose hook up and see if it picks it up faster or.. better yet get it to the ramp and see. I hate to let the engine get hot. When I ran it last week worked fine all but the carbs being dirty.

 

[99yam40]

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

If the new muffs are not allowing proper water flow it could be the problem, but I have seen water pump impeller come apart more than once and Yamaha recommends replacing every couple of years.
And pulling and testing stat is easy to do, make sure to inspect passage for while it is out.
Pulling these common parts as recommended will also keep bolts from locking up and snapping off in the long run if you clean and lube them

 

[Tnmtns]

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

I did as you suggested and replaced the impeller and thermostat today. The alarm is still going off. I did a new post but have yet to learn to navigate this this site back to it! lol. Anyway it cooled down and it I checked all the lines again and restarted it and it ran for 10 minutes and stayed cool. I am going to put it in the river tomorrow afternoon and run upstream just in case. Thank you for your guidance and expert help. Now if I can find my last post !

 

[stylesabu]

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

some engines just don't like the muffs,and the fact that they were new,well just think thats your problem not the cooling system. i have actually built a tub for mine as closest water is an hour away.makes testing a pain. and i always have a portable tank that never is used for anything but testing( i keep it clean and always use fresh gas) once problem is fixed i burn the gasin the car ,lawn mower,or pour it into boat tank. test tank never has fuel sitting init for more than a day or 2

 

[99yam40]

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

http://forums.iboats.com/showthread.php?t=543852&p=3728038#post3728038

If you click on your name and then on view forum posts it will show a list of all of you posts you have made on this forum

Did you just replace the impeller or did you do the kit? what about the housing?
On my 99 C40 the indicator stream never gets more that just warm, never hot. and is strong at idle.
Indicator comes from where water enters motor so should not get hot , must be a water flow problem from pump. Is the indicator stream strong even at idle?

 

[Tnmtns]

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

The flow was normal when it flowed. I just replaced the impellar as that is all the dealer had. The housing looked clean and sharp. I tested the old thermostat and it was working fine. Yesterday I cranked it again with the muffs and it picked up and ran cool and strong. Today cranked it before driving to the river and it never pumped once just blew steam and alarm went off. I am glad I did not hit the river with it as we have 25 mph winds. It is just such a hit and miss. I even tried the old muffs yesterday. It has to be that impellar....... I did make sure the fins bent the correct way and it was seated on the pin on shaft.If I pull the lower unit can I pump water down thru the thermostat hole? I tried blowing air down it and it seemed clear..?