Rage 15: Engine Will Not Start Due to Fuel Malfunction

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Hnu427
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Joined: Sun Nov 03, 2019 7:55 pm

Rage 15: Engine Will Not Start Due to Fuel Malfunction

Postby Hnu427 » Sun Nov 03, 2019 8:08 pm

I recently purchased a RAGE 15 that has only been started and run three times in the last five years. The engine last run this summer before being listed for sale. Now I have [the RAGE 15 boat] and can not get [its engine] to run.

SOME OBSERVATIONS ABOUT THE ENGINE THAT WILL NOT START
--[there is] plenty of spark.
--[If one puts] a little fuel in a few cylinders, [the engine will] pop off.

CONCLUSION ABOUT THE CAUSE OF THE FAILURE TO START
--[the cause of the failure to start is] now obvious: it's a fuel malfunction.

FURTHER TESTING FOR DIAGNOSIS OF FUEL MALFUNCTION
--pulled off the fuel line at the first T-joint fitting to carburetors
--turned engine over
--hardly any fuel moved.

QUESTIONS

Q1: am I doing something wrong [in the process of trying to diagnose and repair the no-start problem]?

Q2: is there a fuel cut off safety relay somewhere that could be causing the fuel flow [to be insufficient to start the engine]?

[The fuel supply hose on the RAGE 15] has had a fuel line primer ball installed. [The engine] still has the original primer button.

I can see a full fuel filter after priming.

Engine cranks over good with brand new battery.

Other than priming the cylinders by removing the spark plugs and adding fuel by hand it will not try to fire on its own.

Any input from readers may help.

jimh
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Location: Michigan, Lower Peninsula
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Re: Rage 15: Engine Will Not Start Due to Fuel Malfunction

Postby jimh » Tue Nov 05, 2019 2:04 pm

What sort of fuel pump does the engine in the RAGE 15 that does not start have?

You mention the engine has carburetors. There should be fuel in the bowls of all the carburetors. Fuel is provided to the combustion chamber be being drawn into the air stream as the intake air flows through the carburetors. The fuel is just sitting in the fuel bowls. It is not being pumped into the air stream or pumped into the cylinders.

The fuel pump on a carburetor engine just delivers fuel to the bowls of the carburetors. The flow of fuel into the carburetor bowls is controlled by a valve. The valve is controlled by a float on an arm inside the carburetor bowl. When the carburetor bowl is low on fuel, the float moves downward as the fuel level lowers. This movement opens the valve. Fuel flows into the bowl, filling the bowl, until the float rises on the rising fuel level and closes the valve.

The fuel pump on most outboard engine carburetors just lifts the fuel from the fuel tank to the engine so that it can flow into the carburetor bowls and keep them full. The power for the fuel pump is usually derived from crankcase vacuum pulses. If you were to open the output hose of the fuel lift pump on an outboard engine when it is turning over at very low speed, as occurs during engine cranking, the volume of fuel flowing out of the fuel pump could be rather low.

Based on your observations mentioned, I do not see where you have checked the carburetor bowls for the presence of fuel. Also, for the float valve to stick in the closed position is possible. If the float valve sticks in the closed position, no fuel will flow into the bowls. Also, if carburetors sit for months, any fuel in them evaporates. What remains is often a sticky residue, particularly if oil was pre-mixed with the fuel before it arrived at the carburetors, a very common situation with older carburetor two-stroke-power-cycle outboard engines.

MarkCz
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Joined: Sat Jan 27, 2018 3:44 pm

Re: Rage 15: Engine Will Not Start Due to Fuel Malfunction

Postby MarkCz » Sun Nov 10, 2019 7:14 pm

Are you using fresh fuel and not old stale gasoline?

jimh
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Re: Rage 15: Engine Will Not Start Due to Fuel Malfunction

Postby jimh » Tue Nov 12, 2019 3:26 pm

MarkCz wrote:Are you using fresh fuel and not old stale gasoline?


The initial post in the thread describes how the engine does fire when fuel is introduced into the combustion chamber. On that basis I don’t think that the age of the fuel as measured by the elapsed time since it was purchased could be the fundamental reason the engine is not starting.

My inference drawn from the narrative is the engine starts when there is fuel in the combustion chamber, and the problem is really there is no fuel being delivered, rather than there is fuel being delivered but it is too old to combust.

In order for me to better understand your concern about the amount of time elapsed since the fuel was purchased at a retailer, I would need to know the basis for the minimum age that gasoline will no longer combust in an internal combustion gasoline spark ignition engine as measured from the date of purchase. Guidance on that would be helpful.

Seahorse
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Re: Rage 15: Engine Will Not Start Due to Fuel Malfunction

Postby Seahorse » Tue Nov 12, 2019 11:19 pm

Can you feel the manual primer pump pressurize the engine's fuel system? That is your first step for troubleshooting the fuel system if you are sure that is the culprit.

Secondly, have you determined if the electric primer is operational? It delivers fuel to the intake manifold when the key is pushed in and in the ON or START position and if the system is pressurized by the primer pump or the VRO. If operational, the fuel injected into the intake manifold would allow the motor to "pop off" even if the carbs were plugged up.

MarkCz
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Joined: Sat Jan 27, 2018 3:44 pm

Re: Rage 15: Engine Will Not Start Due to Fuel Malfunction

Postby MarkCz » Thu Nov 14, 2019 10:18 pm

Is the fuel in the boats gas tank the same fuel you are using to inject into the carbs.

MarkCz
Posts: 26
Joined: Sat Jan 27, 2018 3:44 pm

Re: Rage 15: Engine Will Not Start Due to Fuel Malfunction

Postby MarkCz » Thu Nov 14, 2019 10:20 pm

I meant to say same fuel into the cylinders as what's in the gas tank.