omc 7.4 GL running well on neutral, problem on load

[olivier06300]

My boat is a chris craft concept 27 CC, KING cobra. I'm French;

My engine is running well on neutral, 5700rpm very good. but when i'm boating i can't go up to 3000 rpm and the engine make a strange noise lan internal explosion and moving a lot.

Please have you an idea?

Olivier

 

[OldNBold51]

Re: omc 7.4 GL running well on neutral, problem on load

My boat is a chris craft concept 27 CC, KING cobra. I'm French;

My engine is running well on neutral, 5700rpm very good. but when i'm boating i can't go up to 3000 rpm and the engine make a strange noise lan internal explosion and moving a lot.

Please have you an idea?

Olivier

too vague to make a judgement call. Revving in neutral tells nothing much at all. Check your firing order to make sure the spark plug wires are attached to proper spark plugs.

 

[olivier06300]

Re: omc 7.4 GL running well on neutral, problem on load

thanks OldNBold51 for your ansmer.

But My engine is OK on Neutral no problem of iginition, i have a problem on load when i boating i cannot go up to 3000tr/min, i can heard some internat explosion and the engine is moving a lot. sorry for my poor english.

Kind regards

Olivier

 

[bruceb58]

Re: omc 7.4 GL running well on neutral, problem on load

But My engine is OK on Neutral no problem of iginition,

That engine will run on 4 spark plugs in neutral. You still need to check ignition.

Have you done a compression check?

 

[6meter]

Re: omc 7.4 GL running well on neutral, problem on load

Do as Bruceb58 says and if ok is what you're hearing popping through the carb? Could be a coil. In neutral means nothing.

 

[bruceb58]

Re: omc 7.4 GL running well on neutral, problem on load

Could be a coil.

Rule #1 Its never the coil
Rule #2 Its never the coil
RUle #3 Its hardly ever the coil

We should have a poll on this. How many people have replaced the coil and it didn't fix the problem.

 

[olivier06300]

Re: omc 7.4 GL running well on neutral, problem on load

@Bruce
Compression Ok,
What you mean on neutral the engine will on 4 spark plug ?

@6meter
the noise is note fire back in carb but like a compression sound ...

I will replace all my spark, and try it.

 

[6meter]

Re: omc 7.4 GL running well on neutral, problem on load

Rule #1 Its never the coil
Rule #2 Its never the coil
RUle #3 Its hardly ever the coil

We should have a poll on this. How many people have replaced the coil and it didn't fix the problem.

I replaced my coil in 2008 and just replaced it again this week. It fixed the problem both times. Different symptoms each time.

 

[bruceb58]

Re: omc 7.4 GL running well on neutral, problem on load

I replaced my coil in 2008 and just replaced it again this week. It fixed the problem both times. Different symptoms each time.

Then you should figure out what is blowing your coil. Either it has improper voltage(no ballast resistor) or your spark plugs are gapped too wide or you have faulty wires and or distributor cap.

 

[Icefire55]

Re: omc 7.4 GL running well on neutral, problem on load

best thing to do is a regular maintenance (change plug and wire, look at your cap/rotor if good) retime the motor, if it's pinging (explosion noise) it's probably too advance.

Load probleme after 3000 rpm are normally 4 barrel carburator which the secondairy have problem (too lean, plate stuck) it just happened to me on my 350, secondairy plate stuck, sluggish after 3000

I speak french if you ever need something explained in french, I doutb I can talk french on the board.

 

[olivier06300]

Re: omc 7.4 GL running well on neutral, problem on load

Hi Icefire55

ALors je vais parler fran?ais, sorry for my english speaking friends,

J'ai chang? les bougies, les files de bougies, la t?te de delco et le doigt d'allumeur.
Toujours le probl?me, j'ai un allumage EEM, est qu'il y ades mise en s?curit? du moteur ?
Quand je prends la lampe stromboscopique je voie des coupure d'allumage quand le moteur fait du bruit et je vois aussi l'avance qui bouge, pas stable.

Le problem ce fait uniquement au neutre

C?t? carburation tout semble ok

Merci d'avance

Olivier

 

[olivier06300]

Re: omc 7.4 GL running well on neutral, problem on load

Ok i have fix the problem.

So the problem is the sensor of temperature, not for the indicator but for the alarm.

Thanks every body

Olivier