yamaha 9.9 fuel problem

[amsoilman]

I have a 9.9 Yamaha, that I have tied the fuel line directly to the main boat fuel tank. after just a few minutes of running, it will start to die. If I pump the bulb, it will continue to run for awhile, then die out again, unless I keep the bulp pumped up. I have changed the fuel pump diaphram but it did not help. I was told by the dealer these engines do not have a very efficient fuel pump, and my problem is most likely caused by having the engine connected directly to the boats fuel tank. Dealer says this is to far for the small pump on the yamaha to pull the fuel. I am wondering if I can get a small electric fuel pump to put inline with the fule line that would give me the help I need for the fuel to reach the yamaha outbord.<br /><br />Thanks,<br /><br />Wayne

 

[John from Madison CT]

Re: yamaha 9.9 fuel problem

I remember reading a thread once where someone had this problem and they tied it to using 3/8" fuel line. When they went to a small diameter line, it solved the problem.<br /><br />It had something to do with the fuel pumps ability to pump suck a large volume.<br /><br />What size fuel line are you using?

 

[rodbolt]

Re: yamaha 9.9 fuel problem

how did ya tie into the main tank ?

 

[amsoilman]

Re: yamaha 9.9 fuel problem

I used 1/4 inch rubber hose, and I installed a one way valve in the line going to the main engine as well as the 9.9 Yamaha trolling motor. I was told by the dealer that this had to be done or one or the other engines would syphon fuel.<br /><br />The line I installed is about 14 feet long from the main fuel tank to the 9.9 trolling motor. Dealer said it is not uncommon for this to happen. His claim is that the 9.9 Yamaha I have does not have a very strong pump.<br /><br />I am hoping I can locate an electric fuel pump that I can install in the fuel line.<br /><br /><br />Thanks,<br /><br />Wayne

 

[bb_ed]

Re: yamaha 9.9 fuel problem

I don't think it would be a real good idea to put an electric pump on that 9.9. Maybe you can install a permanent small tank closer to the outboard and fill that with the electric pump.

 

[gss036]

Re: yamaha 9.9 fuel problem

Wayne, did you ever get your problem resolved? Just courious. I have a friend who runs his from a small tank sitting on the swim step, lasts several days for trolling while fishing.

 

[amsoilman]

Re: yamaha 9.9 fuel problem

gss036,<br />I used the small 3 gallon tank when I fist bought the engine. It did work good, but was always in the way when entering or exiting the boat. Beleive it or not, it also affected the boats ability to come out of the water!<br /><br />Wayne