Reassembling johnson 4hp

[cmcm]

Hi all

I have been trying to resurrect an overheating Johnson 4 hp ever since a local repair guy let me down.

I stripped the impellor, removed the mid section and removed the cylinder head. The block turned out to be in the water exits from the cylinder and, having cleared them with a bit of wire the water seems to flow around the cylinder so it is time to reassemble. As I am completely new to this I have a few questions.

Model is E2BRHCRM! which I think makes it 1984.

When removing the leg the drive shaft came out of the foot so it is now totally detached. Is it simply a case of slotting it is at each end or does fluid need to be topped up etc?

I have heard it suggested that for the mid section gasket that silicon sealant can be used instead, is this true?

In the parts diagram there appears to be two metal plates that would go beneath the water pump, one quite solid, the other slightly more 'gasket like', with spaces within the shape. When I disassembled I only found the solid one. Is it possible a part is missing? The plastic file piece is held in place by the solid plate with the pump housing on top.

Finally, when investigating I loosened the nuts for the exhaust plate, looked inside and retightened. I believe the gasket remained intact. Do you think this is likely to suffice or should i try to reseal?

Any help would be appreciated and forgive me for the stupid questions, I wouldn't have attempted it if Ihadn't been let down by the professional.

Cheers

CM

 

[Daviet]

Re: Reassembling johnson 4hp

The drive shaft should slide right back into the gearcase, may have to rotate it a little to align the splines. Make sure the lower unit is full of oil, or better yet, change it and make sure to use new gaskets on the drain/vent screws.
I don't use any type of sealer where the gearcase mates to the exhaust housing.
Here is a breakdown of the water pump, it shows the sequence to put the pump on.
http://www.ishopmarine.com/ishop/js...CatFilter=BRP&eCatSupFldr=supplier-100-005-EJ
It might not be necessary, but you might nat least use some sealer on the the exhaust plate.
On a side note, are you working on a Johnson or Evinrude, the model number is for an Evinrude.

 

[cmcm]

Re: Reassembling johnson 4hp

The drive shaft should slide right back into the gearcase, may have to rotate it a little to align the splines. Make sure the lower unit is full of oil, or better yet, change it and make sure to use new gaskets on the drain/vent screws.
I don't use any type of sealer where the gearcase mates to the exhaust housing.
Here is a breakdown of the water pump, it shows the sequence to put the pump on.
http://www.ishopmarine.com/ishop/js...CatFilter=BRP&eCatSupFldr=supplier-100-005-EJ
It might not be necessary, but you might nat least use some sealer on the the exhaust plate.
On a side note, are you working on a Johnson or Evinrude, the model number is for an Evinrude.

Hi

Thankyou for the reply. It says Johnson on the casing, but I can't gaurantee it is the original. Do you think it is ok to just use sealent where the exhaust housing mates with the engine?

Thanks again for your help

CM

 

[Daviet]

Re: Reassembling johnson 4hp

You can try it, if it don't seal it properly you will just have remove it and install new gaskets.

 

[cmcm]

Re: Reassembling johnson 4hp

Hi

Thanks for all your help. I managed to get the water pump on, but when i reattached the gear case to the exhaust housing the neutral/forward switch didn't seem to have any effect, if I turn the crankshaft then the prop turns, even when it is supposedly in neutral. Any ideas?

i have started to drain the housing and remove the propellor to investigate from that end, but any ideas would help. I'm assuming that if the prop turns then the shaft is in the correct place and therefore the problem must be in the gear case?

Any help would be appreciated. Especially if it doesn't involve removing the water pump again

Cheers

CM

 

[cmcm]

Re: Reassembling johnson 4hp

Hi

I have investigated further and it looks like it is specifically a gearbox issue so I'll start another thread.

Cheers

CM