Engine dies at WOT

[Peter_C]

How does it restart? Do you have to crank for awhile or does it fire right back up?

Sounds like a fuel issue to me, but without seeing and hearing it... First thing would be to check/replace the fuel filter(s). If you don't already have one a nice canister type fuel filter with water separating capabilities is nice to have. I would check to make sure the fuel lines are in good shape and not letting air leak in. Check the fuel pump for pressure and volume. Again a stream of propane shot into the intake as it is dying would confirm it is fuel, but only do it for a second as the motor will not be lubed properly.

If it were a carb problem, most likely it would be more consistent and not run up to full throttle in the first place.

[lockieboi]

Originally Posted by Peter_C

How does it restart? Do you have to crank for awhile or does it fire right back up?

Sounds like a fuel issue to me, but without seeing and hearing it... First thing would be to check/replace the fuel filter(s). If you don't already have one a nice canister type fuel filter with water separating capabilities is nice to have. I would check to make sure the fuel lines are in good shape and not letting air leak in. Check the fuel pump for pressure and volume. Again a stream of propane shot into the intake as it is dying would confirm it is fuel, but only do it for a second as the motor will not be lubed properly.

If it were a carb problem, most likely it would be more consistent and not run up to full throttle in the first place.

It starts first pull straight after cutting out.

I'm a bit of a novice so I think I may to it to someone to look at.

I checked the fuel filter under the hood and it looked ok to my untrained eye.

[Searider]

Originally Posted by Tom465

Well I guess that could be your problem.

For mine it turned out to be low oil. My oil tank had about 1/3 left in it which is enough for about 5 more trips out for me and looked fine.

Turned out when I was cruising along the engine was level and then when I went WOT the boat rises up and would think that I had low oil. It would lower the limiter and would then decrease the lower the oil is.

Jizm made a comment about the "get you home mode" so I thought id just fill up the tank to see if it made a difference. Went out and she was fine !

Note to self, have more than 1/3 oil in the tank Big thanks to Jizm or I would still be trying to fignure out what it could be....

My old 30 yam did the same too!

[willk]

When you squeezed the fuel bulb, did it "firm up", or remain soft, or firm up and go soft again quickly?

You could have a dodgy fuel bulb (damaged valve) or an air leak somewhere in the line, letting air into the bulb. Equally, the fuel pick up may be blocked or damaged or your fuel tank vent might be clogged...

The possibilities are endless!

Oh yeah, do you have a bowl fuel filter fitted to the system???

[lockieboi]

The primer bulb did go soft again but after a short while. But it did the same when not at full throttle and it wasn't a problem then.

The only fuel filter is under the hood.

[willk]

I'd go over the fuel supply if I were you. It does sound like it's either restricted or leaking air in somewhere. Stick your spare primer bulb into the hose and see how that goes. Check all the joints and make sure that the fuel pickup is clear.

[lockieboi]

Originally Posted by willk

I'd go over the fuel supply if I were you. It does sound like it's either restricted or leaking air in somewhere. Stick your spare primer bulb into the hose and see how that goes. Check all the joints and make sure that the fuel pickup is clear.

When you say fuel pickup....................?

[Peter_C]

Originally Posted by lockieboi

When you say fuel pickup....................?

Inside the gas tank. Any kind of air leak could cause a problem.

[lockieboi]

Originally Posted by Peter_C

Inside the gas tank. Any kind of air leak could cause a problem.

Ok thanks, how should I check that's ok?

[jyasaki]

Do you have access to something that pulls a vacuum? Brake bleeder, large syringe, something like that?

If so, close off the tank vent, apply a vaccum to whatever part of the line you want to test, and see if the vacuum holds.

You could, I suppose, also use pressure, but be careful not to overpressurize, and it won't (well, shouldn't) go through the primer bulb.

Neither of these will tell if you've got a blackage.

jky

[Peter_C]

Originally Posted by lockieboi

Ok thanks, how should I check that's ok?

Visual inspection, utilizing a flashlight. Just make sure the pickup is in place, and that it goes to the bottom of the tank.

[ssobol]

Check the pins in the electrical connectors. A long time ago a friend had a boat where the motor would suddenly cut out at full throttle. Eventually it was discovered that one of the pins in the connector from the remote control box was not fully pushed into place. At high rpms the vibration of the engine would cause the connection to be intermittent. To the engine it would seem as if someone turned the ignition switch off.

A bit of foil stuffed into the corresponding female pin solved the problem.

[Tom465]

Check all the hose clamps on the fuel line. Make sure they are tight, even if they visually look so. This also happened to me...

[lockieboi]

Thanks for all the advice.

So many bloody things to check.

Spoke to whistable marine today who want £100 plus VAT plus parts to service it.

Is this a bit steep?

I just want this fault resolved and don't think I'm skilled enough to do it myself.

[Locozodiac]

How old is that engine ? Used to have a 96 Evi 15 HP with same sypmtons, removed cylinder head, cleaned all internal crankcase and head water passages, placed a new well torqued head gasket + new spark plugs and bingo!! Still runing up to date.

Head gaskets are not eternal, with time and use they compress and hardens, when engine is hot lets small water particles pass into combustion chambers causing strange symptoms at speeds higher than idle, worsens between 3/4 to wot and even can shut engine down.

Nobody retorques head gasket when engine has passed break in period because a torque wrench is needed, this causes premature gasket wear due to salt water penetration & corrosion between crankcase and head walls losing perfect chamber seal as when engine was brand new.

If all related fuel, electrical, mechanical is working ok this is the inmediate part to check and change. Remenber outboards are not car that uses glycol for engine refrigeration. To get the idea...

Happy Boating

[lockieboi]

It's a 1999.

Think I'm going to take it to a professional and get it looked at.

Thanks for all the help.

[Locozodiac]

Originally Posted by lockieboi

It's a 1999.

Think I'm going to take it to a professional and get it looked at.

Thanks for all the help.

Post whatever is found, just for the record...

Happy Boating

[lockieboi]

Got the OB back today.

Fuel line checked all the way to the carb and carb cleaned.

Idles a lot better now.

Will see if the fault has cleared the weekend.

Thanks for all the advice.

[mister p]

Just an idea,
Your fouling of the prop will have created a mess. All sorts of vacuum issues with stalling and sucking shit it under higher pressure than it should be. You'll be hoovering up all sorts of shit from plenums, fuels bowls etc., esp. if it's a forced stall and not an powerhead one (fuel starvation or electro).
Probably has been said but I read the first and last page only, having experienced this myself ( professionally and on hols ), I'd clean out all your fuel reservoirs. Floats, filters and tanks. It only takes one paint flake to hide and cause hell Taliban style and you're mullered.

[lockieboi]

Well after paying out for this to be fixed it still is not.

Took the boat out for a run earlier and after about 2 mins at WOT it died.

In the process of uploading some videos to YouTube so will put links to them on hear soon.