Yamaha Malta

[Boathook]

The 'gear' lever on mine has now seized solid requiring extra leverage (spanner) to operate it. I know that it isn't the gear box as I have disconnected it and that bit moves OK. I assume that it is something to do with the linkage from the lever itself. If I undo the 3 bolts each side of the engine (ringed black and red) will the power head come off once I have broken the gasket seal and does this then expose the crank or is this hidden by another 'plate'. Does anyone have experience of the Malta innards or even a diagram or few pages of a workshop manual they could share with me. Hopefully the picture is adequate in showing the bolts. I have over the years taken most bits apart on the Malta but don't want to wreck what is otherwise a nice engine.

 

[steve66]

VicS is your man

 

[VicS]

The 'gear' lever on mine has now seized solid requiring extra leverage (spanner) to operate it. I know that it isn't the gear box as I have disconnected it and that bit moves OK. I assume that it is something to do with the linkage from the lever itself. If I undo the 3 bolts each side of the engine (ringed black and red) will the power head come off once I have broken the gasket seal and does this then expose the crank or is this hidden by another 'plate'. Does anyone have experience of the Malta innards or even a diagram or few pages of a workshop manual they could share with me. Hopefully the picture is adequate in showing the bolts. I have over the years taken most bits apart on the Malta but don't want to wreck what is otherwise a nice engine.

It will be the shift lever shaft seized, where it passes through the top of the casing as sure as eggs are eggs.

You will find exploded diagrams at https://www.boats.net/catalog/yamaha

and a Service manual that should cover the model at http://www.boatinfo.no/lib/library.html ( I think I'd ignore that though)


Sort it out before you snap it off.... which is what will happen if you keep on levering it with a spanner

 

[anoccasionalyachtsman]

Yes, those six bolts will get the powerhead off, and with it comes the exhaust tube from down in the leg. The top of the leg looks like this.


No idea why I took that one, must have known you'd come along...

 

[Topcat47]

The photo looks as if it's in remarkably good condition. The lever only operates a dog clutch (from memory I"m sure VicS will know better than I. Apply plus Gas or something similar and work the linkage gently to and fro'. Vic is right, the longer you lever it with a spanner the greater the likelihood you'll break it. Wish I still had my old one.

 

[anoccasionalyachtsman]

The photo looks as if it's in remarkably good condition. The lever only operates a dog clutch (from memory I"m sure VicS will know better than I. Apply plus Gas or something similar and work the linkage gently to and fro'. Vic is right, the longer you lever it with a spanner the greater the likelihood you'll break it. Wish I still had my old one.

It is in very good condition - bought from a forum person a year ago. I now have two, because I bought a long shaft from another forum member more recently.

My tip to the OP is to give the bottom of the crankcase and cyl head a salt clean out while he has it in his bench. The one in the picture was almost solid with it, and you wouldn't think it from that picture of the cooling passage.

 

[Boathook]

Nice picture showing the linkage. Wouldn't surprise if the water channel is blocked on mine as I regularly end up taking the head off to clear those channel's. I also have 2 of them and swap over as required! Will have to follow VicS links on my main PC tomorrow for hopefully some diagrams.

 

[Boathook]

VicS.
Shaft lever was seized where it passed through the lower casing by what seemed to be a mixture of salt and sand.
With the boats.net site they don't list the Malta (6L5) but the closest seems to be the 3hp, 3SG-1988.
I'm now trying to clean some water channels within the crank casing and it seems that I may have to remove some plugs. Seems 10 steps forward and then at least 9 back ....

 

[anoccasionalyachtsman]

VicS.
Shaft lever was seized where it passed through the lower casing by what seemed to be a mixture of salt and sand.
With the boats.net site they don't list the Malta (6L5) but the closest seems to be the 3hp, 3SG-1988.
I'm now trying to clean some water channels within the crank casing and it seems that I may have to remove some plugs. Seems 10 steps forward and then at least 9 back ....

That sounds a bit odd. I cleaned mine out completely without removing any plugs but I can't remember exactly how I did it (because I did a Mariner 2hp at the same time and memory won't differentiate) either I could get down the in and out with an implement once the head was off, or the passages were exposed by having the exhaust off the powerhead. Again, as I recall it there isn't a lot of cylinder cooling, it's just the head and top of the cylinder that have passageways.

 

[QBhoy]

Hi
Just thought I’d add. If this is the earlier model Malta that doesn’t have a visible tell tale water flow...whilst you have it apart I’d mayne do the modification that allows a tell tale.

 

[Boathook]

Hi
Just thought I’d add. If this is the earlier model Malta that doesn’t have a visible tell tale water flow...whilst you have it apart I’d mayne do the modification that allows a tell tale.

The one I'm working on has the piddle bit my other one doesn't. That will be my next home based project.

 

[Sandro]

I stumbled upon this old thread.

I have a Malta of the old model, without a cooling water telltale and would like to make one for peace of mind but I never did it, not knowing where piercing it without dismantling the motor.

Now the anoccasionalyachtsman’s picture gave me some hint. Two cooling passages can be seen: to the right the incoming with the tube; to the left the output of the water to the exhaust . IMHO this takes place through the indent visible in the wall at the bottom (in the picture) of the left passage. Am I right?

I am planning to drill a 2.5 mm hole, vertical (with motor in running position) in the top (in the picture) area of the left passage.

Boathook where is the piddle bit in your’s?

Yes I know a sensible mechanic should never leave drill chips inside a machine but in this particular case the aluminium chips at the first motor run would be washed in the dirty exhaust and expelled without consequences.

If the project turns out to be feasible I‘ll do it when the Virus will allow me to go to the boat.

Thanks in advance for advices

Sandro

 

[anoccasionalyachtsman]

If you give me a few days I've got my spare Malta apart in the workshop and I can have a look. Gut feeling is that that left passage is unused and the hot water goes down the exhaust tube. More soonish.

 

[Sandro]

Thank you very much!

Down the exhaust large tube -outboard leg - coming from the left passage through the indent. Or where from?

Sandro

P.S.: Given the worldy situation I am afraid there is no hurry.

 

[Boathook]

This shows my modified outboard where I drill the telltale hole. The drill bit is 3mm and a snug fit. When I drilled it the location was roughly the same as shown in anoccasionalyachtsman's picture in post 4. I don't think that I would have drilled the hole without the engine in bits as the castings are slightly different, though I don't remember much difference internally at the time.




This 2nd picture shows the factory 'made' telltale which seems in a slightly different position to my modified one. The hole is between 2 and 2.5mm diameter

 

[QBhoy]

I have the older model like yours fully in tact and running and also the newer one with tell take with just the power head and upper section, in bits. I’ll have a look for you. I plan to use the one with the tell tale together with the older one

 

[QBhoy]

This shows my modified outboard where I drill the telltale hole. The drill bit is 3mm and a snug fit. When I drilled it the location was roughly the same as shown in anoccasionalyachtsman's picture in post 4. I don't think that I would have drilled the hole without the engine in bits as the castings are slightly different, though I don't remember much difference internally at the time.


View attachment 86936

This 2nd picture shows the factory 'made' telltale which seems in a slightly different position to my modified one. The hole is between 2 and 2.5mm diameter

View attachment 86937

Brilliant.

 

[Boathook]

If you give me a few days I've got my spare Malta apart in the workshop and I can have a look. Gut feeling is that that left passage is unused and the hot water goes down the exhaust tube. More soonish.

I think that the left hand channel (picture in post 4) is where the hot water exits the engine down the exhaust tube. The water comes up into the rhs through he copper pipe from the pump. It circulates round the engine and cylinder head until the thermostat. Thermostat opens and allows the hot water down in to the LH channel and then into the exhaust. There is an overflow just above and to the left of the telltale hole (pic post 4) but that is internal down the exhaust and presumably to allow enough flow to stop the pump overheating and to cool exhaust system. The picture below shows the LH channel is used but here is is at the bottom. As can be seen this malta was lovingly cared for and run in freshwater after being in saltwater !!!! This was the one with the gummed up gear change.

 

[Boathook]

I have the older model like yours fully in tact and running and also the newer one with tell take with just the power head and upper section, in bits. I’ll have a look for you. I plan to use the one with the tell tale together with the older one

Check all the water ways with a bit of wire. This is how I had to sort one out on the power head! Took a lot of 'digging out' as well to clear out the salt / sand mix. Engine well used last year with no problems.

 

[QBhoy]

I’ll have a look tomorrow at both of mine.