Evenrude 115 fitch idle runs up high then low

[Nigelbb]

I have a 1998 Evenrude Fitch 115 hp outboard Engine. We went to start this recently and the motor will not idle correctly, it revs up to very high 6000rpm then drops to about 1200rpm then again runs up again then we shut it off as too high rpm.
We have new clean fuel and new plugs indexed.
Any ideas please

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

You'll have to get a dlr to put his laptop on it to see if there are any codes. Shooting from the hip, you may have a fuel pump with a ruptured diaphram in it feeding into the c/c causing this.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Thanks very much boobie for your sound advice.
Its now going to an Evenrude deeler next week.
I will inform them about your point ruptured diaphram and see what the codes come back with.
Also forgot to say that when it did start a lot of black dirty stuff came out in the water across the driveway like carbon soot or similar in the water.Could also smell gas when reving.

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

The fuel pump may not be the prob but that mtr had probs in that year having this happen. If you can find the fuel lift pump, disconnect the pulse lines going to cyls 1 & 4 in the c/c, disconnect the lines and pump the primer bulb. If you see fuel coming out of them, that's your prob.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Sorry but i do not know what is c/c?
Thanks for advice again!

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

c/c= crank case or intake manifold. By the way, you could also have probs in the vapor seperator letting fuel get into the vent hose going to the c/c.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Hello Boobie,
You were right on the money with my Engine idle issue.
It went to an evenrude deeler and they did the same test and fuel was gushing out a rupture diaphram.
Thanks again! That ethinol must eat the rubber diaphram.

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

I wouldn't blame the ethanol just yet. Your mtr had this prob before ethanol came out and OMC had probs with those fuel pumps. Just make sure you have a good water/seperator filter installed in your fuel system. Glad you got it fixed.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Hello Again Boobie,
Well my Fitch engine is running well now that the diaphram was replaced.
I ran into a couple of small problems this time with my Boston Whaler which the fitch is mounted on.

1. I noticed that when i try to start the engine sometimes the starter only trys for short time and does not keep cranking?

2. I was out in the boat the other day and lost my gauges like rpm,fuel, and trim gauge. However the engine was still running and they came back on later that evening after the boat was docked?
Is this a ground problem like a dirty ground?
it looks like all the gauges have a common power feed a purple wire.
Any feedback would be helpfull

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

Check ALL the battery connections on both the battery and the mtr for being good, clean and tight. Also your wires going to the boat on your battery to power your accesories.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Ok will try all connections to both batteries and make sure they are clean and tight.

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

Don't forget, I said All!!! battery connections.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Hello Booby,
I have not had chance yet to clean all terminals on the boat yet with regards to my cranking issue.
A question does the ECU have any control over how many times the starter cranks?
Or does the ECU not get any feedback from the starter? Interesting.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Sorry should have called you Boobie and not Bobby!

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

The ECU should not have any effect on how many times the starter cranks. I'm still shooting for bad connections.

 

[Nigelbb]

Re: Evenrude 115 fitch idle runs up high then low

Well Boobie you were right again.
It was the Battery connection and also a 65% battery under load, so new battery, clean terminals and it cranked over like a champ.
Thanks again

 

[boobie]

Re: Evenrude 115 fitch idle runs up high then low

You're Welcome.