Moderated Discussion Areas
  ContinuousWave: The Whaler GAM or General Area
  Fuel Starvation?

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Fuel Starvation?
bmoreland posted 05-26-2002 11:56 PM ET (US)   Profile for bmoreland  
Incurred a problem on my OR 18' this weekend...every time throttle advanced above 3500 RPM, on 1992 150 Yamaha, it would back down and act like it was not getting fuel. Happened repeatedly, although delayed reaction (30 seconds). The engine never quit, but after a minute or so at idle, was good to plane @ 25 MPH, then might back down again, worse if you really goosed it. Any thoughts, I'm thinking fuel filter(s).
Guts posted 05-27-2002 01:21 AM ET (US)     Profile for Guts  Send Email to Guts     
primer bulb?
Bubba posted 05-27-2002 02:31 AM ET (US)     Profile for Bubba  Send Email to Bubba     
There is a plastic dip tube below the screwed fitting where your fuel line attatches to the gas tank. If the tube is craked it will suck air when the fuel level is below the crack causing the stalling you discribed. When you are rising to plane the level is higher and you will get fuel. After on plane again it will suck air and stall out. The engine will run on idle, it seems that you can get enough fuel to idle.
just my 2 cents worth.
Boston Marine posted 05-27-2002 03:28 PM ET (US)     Profile for Boston Marine    
Could it be that your engine is activating the overheat circut and by default the yamaha wont let the engine run at hi speed?
My 3 cents.
Tom W Clark posted 05-28-2002 12:08 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

Your fuel starvation problem is not uncommon. While it could be any of several different things I suspect it is a fuel restriction somewhere in your boat's fuel system. Many of the 18 Outrages have suffered this and there are several good threads about it here on the FORUM.

My own 1983 used to suffer from this phenomena. Whenever it happened, the primer bulb would be collapsed. A collapsed primer bulb itself may result from any of a number of things but I would suspect a faulty fuel check valve in your tank. Read more about these here:

To diagnose your problem, first check to see if the primer bulb is collapsed the next time it happens. Make sure it is oriented correctly, i.e. the arrows point towards the motor.

You could try a new primer bulb as an easy first step. Buy an OMC primer bulb and not the Tempo knock-offs. These seem to be the best of them and it does not matter what brand of motor you have.

You may want to check or simply replace your fuel filter cartridge as well as inspect for any crimps in the fuel line.

bajabreeze posted 06-01-2002 05:59 AM ET (US)     Profile for bajabreeze  Send Email to bajabreeze     
When was the last time you changed the plugs? Possibly a cracked ceramic. What about water in your carb bowls? Have you drained them lately? Use som carb cleaner to fkush them out. Sometimes something as simple as a worn or cracked fuel connector at the engine can let air in at higher RPM and cause a loss of vacumm.

Alan Hiccock posted 06-01-2002 01:32 PM ET (US)     Profile for Alan Hiccock  Send Email to Alan Hiccock     
Check for small cracks by the barbs that lead into the fuel filter
rubadub555 posted 06-04-2002 04:27 PM ET (US)     Profile for rubadub555  Send Email to rubadub555     
Bmoreland never reported back, so I don't know if the prior suggestions solved the mystery; I noticed the same phenomenon when, as I got up on a plane, my tank crept aft and pinched the fuel line in my 1980 Montauk; a few dollars worth of strap and a plastic lock/buckle later, the tank was held in place, and easily unbelted for fuelling...
bmoreland posted 06-09-2002 10:43 PM ET (US)     Profile for bmoreland    
Started pumping the bulb as engine was cutting out. After several times, it seems now to be fixed. I think I must have had some crud from the tank lodged in the bulb and the manual pressure while running flushed it through. Still going to change ou the filters for good measure. Thanks for all the responses. Hope I can return the favor.
tully_mars posted 06-10-2002 04:07 PM ET (US)     Profile for tully_mars  Send Email to tully_mars     
Better check your jets in the carbuerators, especially the hi flow jet. My motor did the exact same thing until the #3 piston siezed up from lack of fuel. When you have a lack of fuel then you have a lack of oil and the temp in that cylinder being starved goes sky high. Thus, you can sieze a piston.

That was a $2000 lesson to be learned, when the motor doesn't want to run fast, don't force it. It is trying to tell you something.

Tully Mars

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.