115hp fuel or timing problems perhaps?

[voonerf]

thanks in advance regarding this issue.

I am having an odd issue with what I thought at first was water in the fuel. I recently removed all the gas and let the tank dry before adding new fuel and changing water/fuel seperator.

right now the boat will idle with a small problem of what sounds like the timing is incorrect because of the puff sound like air coming up through the carbs I am thinking. I am in the process of checking the timing.

I did take the boat out today just to see if the fuel was the problem but after about 7 minutes the boat bogged down and had troubles starting. I was able to start the motor back up and only was able to get about 6-8mph heading back to the ramp. while heading back the boat bogged down and died a few times.

at home with the hose it seems to fun fine but still with the puff every so often could this be what is causing my loss of power and lack of fuel so it seems?

any help on this issue would be great, again thanks for taking the time.


James

 

[Lone Duck]

Re: 115hp fuel or timing problems perhaps?

Did you rain the water from your float bowls and primer bulb?

 

[cousinabe]

Re: 115hp fuel or timing problems perhaps?

that puff or cough you mention could be a lean sneeze which is mostly carb related.

post the model number off the port side of the bracket.

 

[voonerf]

Re: 115hp fuel or timing problems perhaps?

sorry for the late response

Loneduck: yes I did drain the water/fuel from the bulb but not from the carb bowls the motor has run dry a few times so I assume the bowls emptied out. but you know what they say about assuming.

Cousinable: the numbers for the boat model are s115tlrx 6e5 l405190, I think your solution to the cough sounds is very likely the cause of the problem. trying to read though the repair manual on how to properly adjust the air/fuel mixture. Assuming (yet again) that this is how to adjust the lean/rich mixture.

 

[voonerf]

Re: 115hp fuel or timing problems perhaps?

adjusting the fuel to air/mixture seems to help don't have the cough at idle anymore, but i did notice that the fuel filter seems to drop from time to time. when i say drop goes down to about half full or half empty depends on how you look at it . i am currently looking at pricing for a fuel pump rebuild kit if that is needed.

 

[cousinabe]

Re: 115hp fuel or timing problems perhaps?

I would go through those carbs and make sure they are clean.

A lean sneeze can blow a lp fuel pump diaphram and more importantly pop a piston or do bearing damage. You want to address that sneeze and resolve.

Most people replace their fuel pumps after 3-4 seasons. at $34 each, it's cheap preventative maint.
I have bought OEM ones from http://www.boats.net/parts/search/Yamaha/Outboard/1999/S115TLRX/FUEL/parts.html @ $34.05 and replacement diaphram kits from sierra http://www.marineengine.com/parts/p...8&returntopage=sierra_parts/8024/80240380.htm @ $7.04. The quality of the OEM diaphrams are much better.

Also, I would start off with the link and synch adjustments per manual.
http://books.google.com/books?id=Q-_04jB_etYC&printsec=frontcover&dq=yamaha+outboard#PPA148,M1