mariner 3.3 seized engine

alteredoutlook

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Hi all,

I have a mariner 3.3hp 2 stroke engine thats seized. I've stripped most of it down and diagnosed the big end is rusted on to the crankshaft.

Before I put it all in the bin the thought has occurred can i repair it. Is it economically viable??

The rest of the engine is only in average condition and by the time I've bought new gaskets and bearings, etc i'm wondering is it worth doing.

Does anyone know a cheap source of parts ? Perhaps they have some 2nd hand useful parts lying around?

Any advice much appreciated!

thanks
 
I had a Tohatsu 3.5, an almost identical engine, which seized its main bearings due to a dunking. These are not highly-tuned engines and handle tolerances some way from blueprint. After freeing off with a large breaker bar, it ran like a bag of nails, but progressively became smoother and quieter as it ran itself in all over again. About three years later it showed signs of crankcase seal failure (probably due to the additional movement permitted by the old bearings) and was rebuilt with new mains, seals, rings etc, which gave it another new lease of life. The cost of parts was a bit of a shock, but the job was worthwhile, given the effective outlawing of such engines new. In fact the rebuild made it so desirable it was subsequently nicked in Martinique.

Obviously replacing big ends (and, presumably, the rod) is more bothersome, and tolerances probably more crucial, although many motorcycle shops will be able to press the crank apart to fit them.
 
I'd look at what the spares might fetch.
Barrel, piston, transom clamps, see what other bits are selling in ebay's 'completed listings.
then look at cost of a good used crank or a running motor.
I had a Mariner 3.3 from new, IMHO a long way inferior to a Yamaha.
 
Hi all,

I have a mariner 3.3hp 2 stroke engine thats seized. I've stripped most of it down and diagnosed the big end is rusted on to the crankshaft.

Before I put it all in the bin the thought has occurred can i repair it. Is it economically viable??

The rest of the engine is only in average condition and by the time I've bought new gaskets and bearings, etc i'm wondering is it worth doing.

Does anyone know a cheap source of parts ? Perhaps they have some 2nd hand useful parts lying around?

Any advice much appreciated!

thanks
If its only "rusted" I would play with it and some freeing oil! If its seized due to lack of oil maybe not so ressurectable.
 
Easy cheap repair. £15 if you havent taken off the head,£20 if the heads been removed

Bearings off ebay...do not buy genuine. They are 6000 series. Im pretty sure ones 6004, not sure about the other can find the size for you if your stuck and a base gasket. Literally a 15 minute job
 
I think the big end is rusted not the mains but you would want to do them at the same time. (You might even want a new piston and rebore whilt it's all apart)

Rod kit £35
Pressing £35
Mains and seals £20
Gaskets £35

If you did want to sell it for spares I would be interested in the engine in bits for mine. Pm me if so.
 
My Mercury 3.5 failed when it was put away (not by me) upside down when it still had seawater in the exhust system. When I disassembled it both the big and little ends (which iirc use needle rollers) were seized. But some penetrating oil, followed by 1/2 an hour in the oven, followed by more oil and a mallet and I got a degree of two of play, then 10 degrees, then 45 and finally turning. I cleaned up the rusty gunge and reassembled with new crank-case gaskets and it ran fine, if jolly noisy and rough, for about 5 years. Then the piston ring snapped, so I replaced that, and it's been running ever since - 3 years now making it 8 or 9 in all. So Mr Cronky still lives - and still sounds really bad! So bad that locals wince when we come by, and it wasn't stolen in Martinique.
 
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