Logo
FULL SITE MENU

2005 Yamaha F115TLRD bogging problem

C

chikester

New member
Looking for some help here, all repair shops are at least a 2 week wait here.

Engine started at first bogging when I got to about the 4K RPM range (it's on a pontoon boat). Didn't think much of it and just cruised at low RPM for the holiday weekend. It started to gradually get worse and started starving at low RPM's as well, had to keep pumping the bulb to go. Here are the things I have done.


  • running off brand new portable tank with new gas, hose and connections- made no difference
  • Installed a brand new low pressure fuel pump- help a little but still starves for fuel.
  • Put a fuel gauge on fuel rail while on muffs, at idle it was at about 37 PSI, bumped it up to 1200K RPM and it was about 39 PIS
  • Took VST apart and it was very clean, screen was clean. Float appeared to function correctly.
  • Had an extra set on new injectors, installed them and that did not help.
  • Looked everywhere for leaking or crimped fuel lines on engine, could not find anything.
  • when I turn key I can hear high pressure fuel pump kick in.

So I am lost what to try next, it seams like the VST tank cannot keep up with the engine, I am thinking the high pressure fuel pump may be bad or weak but hate to throw $350 at it not knowing if that is the problem.

Can anyone think of something I may be missing ?
 
37 psi at idle is plenty. I would assume the high pressure pump is fine.

If you can still pump the bulb and it works better, there has to be a leak somewhere.
 
Thanks, at least I know now that it is somewhere on the engine side since I ran it on a portable tank. I think I may take the VST tank off again and check the fuel lines going to them since I have not replaced them.
 
Okay, I opened the VST up again and found the filter screen and the rubber piece unattached from the fuel pump. Took it out and the screen is nice and clean but the rubber cap does not hold tight to the pump, should it ?

Also on the HP pump, when I took it out I tested it with 12 volts, It works but it goes in short burst and not continuous, anyone know how its supposed to work ?

I am going to attach the float needle tomorrow, it looks kind of corroded up there, maybe it has been sticking or not letting fuel in.
 
Tech said you can bend float up passed settings,in vst chamber as long as you keep lever to needle perpendicular to vst chamber. So vst chamber holds more fuel?
 
Thanks, I'm still waiting to find out if fuel pump is supposed to run continuously or in pulses like mine is now before I put it back together.
 
Back
Top