1984 4hp deluxe exhaust problems

[riley2009]

Hi, ive got a 1984 4HP Evinrude Deluxe Longshaft, i was out motoring around friday night, and the engine cut out, wasnt looking at cooling water stream at the time. Got the engine started first time engine ran for about 2 minutes then the cooling water stream then became a white colour and engine then cut out and wasnt able to be restarted untill following day, i can get it started now and run it at high revs, low revs it cuts out, it seems that the exhaust gases are mixing with the cooling water and coming out of the same hole. any ideas?

 

[Vic.S]

Re: 1984 4hp deluxe exhaust problems

Deluxe model ? This the one with FNR gear shift? (made in Belgium?)

model number would tell a bit more about it but I suspect its one not listed on the American parts lists.

In UK by any chance?

If FNR gears it has a similar gearcase and leg to the 6hp models

Surprised it has a cooling water telltale .. AFAIK the standard 4 hps don't . Or are you just looking at the relief port on the back of the leg

I reckon you start by looking at the water pump but a compression check might be a good idea.

While the lower unit is is off put a hose on the bottom of the water tube to make sure you can get a water flow through the engine. If not the you will have to investigate the reasons. The 6 hp has problems with the grommet at the top of the water tube but the standard 4hp is different.
The water channel around the head can get scaled up and blocked.

Standard 4 has no thermostat. If the deluxe one does it will be under a three bolt cover at the top of the cylinder head

Any signs of overheating ... discoloured paint or melted plastic esp around the head.

I am concerned that it may have overheated to the point of warping the head and causing a head gasket failure . The compression test might give an indication of this if it has.

Hopefully I have got it all wrong, the white cooling water is a red herring and all you have to do is clean the carb!

 

[riley2009]

Re: 1984 4hp deluxe exhaust problems

Yes i am in England it says 4hp but im told its a 6hp yes its from belguim it has FNR Gears, It hasnt overheated nor is it overheating while its running, engine stays cool problem is the white water because it seems that the exhaust fumes are mixing with the cooling water and coming out of the tell tale hole.

Once u engage it into gear the engine will cut out, but if u bring the engine out of the water it will run in gear fine no problems, once the engine is then lowered into water it will start having a good water stream then it cuts out.

Can the exhaust system be blocked inside the powerhead at all?

 

[Daviet]

Re: 1984 4hp deluxe exhaust problems

If it is like a 6 hp, the exhaust and cooling water will mix togeather when it comes out of the exhaust port about 2/3 the way up the exhaust housing.
It sounds like you might have an ign problem when the motor is under a load, have you checked spark and compression?

 

[Vic.S]

Re: 1984 4hp deluxe exhaust problems

The model number which should be on plate on the port side of the transom bracket ( just visible in the pic below , which is of an '84 6 hp Yachtwin) and also on disc on the power head partly hidden by the two ignition coils, will tell us the model exactly.
It'll contain the numeral 4 for a 4hp, a 5 for a 4.5hp or 5 hp and a 6 for a 6hp. It'll also contain the letters CR if it is a 1984 model

Note the exhaust relief outlet on the 6hp is behind the square cover you can see at the very top of the picture on the back of the leg .. its not 2/3 the way up, its right at the top!

No i don't think the exhaust can be blocked. the exhaust manifold outer cover is the plate that the telltale elbow is screwed into.

If you can keep a finger on the cylinder block for a count of 3 it confirms that it is not overheating.

I am thinking maybe that the head gasket has gone. I'm also wondering if exhaust could get into the cooling water if one of the exhaust manifold gaskets had gone

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BTW for spares in the UK make a note of Outboards Direct (aka Oakley Marine) in Brighton and Willsmarine in Kingsbridge