# Motor dies



## fishhawk (Jan 4, 2010)

I have a KW Stealth with a 1994 115hp yamaha 2 stroke. My problem is I can run about 2mi. at 4500rmp and the motor will start to buck and then shut down. I wait about 30 second pump the ball and she'll run about a 1mi. and do it again, the longer I wait to restart the motor the longer she'll run. I have connected a portable 6 gal. tank to motor and it runs with no problem. I have also checked the inboard gas tank vent and it is clear. Any suggestions out there?


----------



## Frank_Sebastian (Oct 15, 2007)

Does the bulb collapse when it dies? If so there is a check valve in the tank feed that may be partially blocked. If not then I would suspect an air leak somewhere in the fuel line.

Best regards,
Frank


----------



## Frank_Sebastian (Oct 15, 2007)

One other thing I thought of is a clogged screen in the pick up tube in the tank.

Frank


----------



## Brett (Jul 16, 2008)

If it runs fine on another fuel tank and hose,
then you know it's a fuel system problem.
15 year old fuel lines? I'd replace them from tank to engine.


----------



## fishhawk (Jan 4, 2010)

Frank, fuel ball does not collapse I also was thinking air leak. Brett, rerouting a new gas line sound like fun but I'm sure it isn't. I'm going to try some new hose clamps and a new ball tomorrow. I was able to blow air in the gas hose from motor to tank. I know this will not tell me if there is a air leak or not, but at least the line is clear. I forgot to mention there is a water seperator also in the gas line, could this be a problem.


----------



## Brett (Jul 16, 2008)

Air leaks can occur anywhere from the fuel tank to the carb inlet.
Finding the leak is entertaining. Previous post...

http://www.microskiff.com/cgi-bin/yabb2/YaBB.pl?num=1259293416/2#2


----------



## mark_gardner (Mar 18, 2009)

sounds like she's starving for fuel, when you stop to pump it all's good till she runs out or isnt able to keep up with the flow??? possibly because of a clogged filter??? , if you cant remember how long its been since changing the filter then that needs to be done for sure and also at your earliest convienence i would definitely change out the fuel lines. good luck


----------



## anytide (Jul 30, 2009)

x2 filter?
-anytide


----------



## fishhawk (Jan 4, 2010)

Thanks for all the help guys. I will be working on the motor this week, I'm putting the boat up for sale. I bought the Native skiff that was on ebay.


----------



## fishhawk (Jan 4, 2010)

I replaced ws filter, didn't replace gas line. Took a ride ran like a raped ape for about 3mi. then shut down I looked back and gas line ball was collapsed. You guys got any suggestions.


----------



## Brett (Jul 16, 2008)

> If it runs fine on another fuel tank and hose,
> then you know it's a fuel system problem.
> 15 year old fuel lines? I'd replace them from tank to engine.


----------



## fishhawk (Jan 4, 2010)

I hear ya I hear ya, man thats going to be a job! 15 years of being a electricain and I don't know if I can fish the hose up to the tank.

If there was an air leak in the gas line would the ball collapse.


----------



## Un-shore (Sep 27, 2007)

> I hear ya I hear ya,  man thats going to be a job! 15 years of being a electricain and I don't know if I can fish the hose up to the tank.
> If there was an air leak in the gas line would the ball collapse.


connect the new hose to the old with a fitting and pull the old hose and the new will follow.


----------



## fishhawk (Jan 4, 2010)

sounds like a plan, I'll give it a try


----------



## Brett (Jul 16, 2008)

One other thing to look at...as Frank said before,
the pickup tube can be blocked down in the tank.
The screen over the opening on the underside of the tube
can be covered with sediment or varnish deposits.


----------



## fishhawk (Jan 4, 2010)

Tried getting the pickup tube off the tank, no go. Now I'm thinkn about blowing air down the pickup tube. Any input?


----------



## MATT (Apr 30, 2007)

Dude, You got old fuel lines and have been running e-10 gas...Buy some of the gray fuel lines and call me I will help with the replace job...


----------



## fishhawk (Jan 4, 2010)

Frank thanks for stopping by and the help. I 'll be trying to get the gas out of the tank tomorrow. Hope to save some of the gas.


----------



## Frank_Sebastian (Oct 15, 2007)

Great to meet you Bud. I hope the fuel salvage project goes well. I have punches that can cut the opening for the fuel gauge if you need to fabricate a proper patch for the top of the tank.

Should we post what was found and the solutions to date?

Best regards,
Frank_S


----------



## Brett (Jul 16, 2008)

I'd like it, I never turn down the opportunity
to see what caused an engine problem and what solved it.
Might have to deal with it myself one day.


----------



## fishhawk (Jan 4, 2010)

Frank I got most of the gas out of the tank. I put the gas in some 5gal. jerry cans and filled up a 6gal. portable boat tank. I connected the gas line directly to the filter on the motor. I read on another forum that the Yami's inlet gas connector can go bad so I deleted it. I put the boat in at the city ramp and the motor ran great.

What we found wrong with the fuel system was I had hole in my inboard tank thus letting water into the tank and the fuel blockage was caused by the water separator filter.

Frank could you explain why the filter wouldn't let the gas flow thru it. I have very little knowlegde of this type of filter


----------



## Brett (Jul 16, 2008)

Water in the fuel tank is a problem because water is denser
than gasoline. Water settles to the bottom of the tank and
so is pulled first from the tank by the pickup tube.
All this water fills your fuel line and ends up at your inline fuel filter/separator.


----------



## Brett (Jul 16, 2008)

The fuel filter/water separator was doing it's job until
the canister was filled almost completely with water. 
Small amounts of gas would be trapped at the top of 
the separator and that accounts for your few minutes of run time.

As long as the water level trapped in the filter/separator
stays below the bottom of the filter inlet, fuel feeds through.
But once the water level in the separator gets above the bottom
of the filter inlet, fuel flow becomes impeded.
If the water level fills the filter canister, fuel flow is blocked.
All that gets pumped to your engine is water.


----------

