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33HP Evinrude Ski Twin

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isocron

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"Hi,
I've just bought the

"Hi,
I've just bought the above motor, and am seeking some advice. I'm currently guessing that it is a 1970 model (the model number is: 33052M).

It seems sound (I have got it to run once!) but it ran a bit roughly, and there were a few sparks from the exhaust and a strong smell of petrol - although I was running it on 25:1 (I've subsequently learnt it should be 50:1 - how much difference does this make?). It has (apparently) not been used for a few years, and would therefore require a service.

So, what are the areas that need the most attention. I'm currently assuming a carburettor overhaul, water pump, points/plugs. Are there any special lubrication areas that need attention, andy particular weaknesses ?

Now, I'm comfortable working with car engines - never done a boat engine. Any special hints ?

thanks, and regards,
ted"
 
"The first thing you should do

"The first thing you should do is get a Seloc repair manual, in my opinion it is the best aftermarket. You can buy it right here on this site. One thing you didn't mention in obvious repairs is the gearcase. Have you checked the oil in it? There are two large slot head screws one drain & fill and one to check the level. Remove the one on the bottom cap and see what comes out.(do not touch the Philips head screw on the cap) If water or a creamy coloured liquid is present, you need a reseal.
The very first thing you should check before spending a lot of time and money is to check the compression. both cylinders should be at least 100# and within 2-3# of each other.If it is, do the coils, points, plugs, condensers, carb rebuild and replace the impeller and plate(usually the WP housing is OK)
My advice for oil/fuel ratio for any old motor is 24:1, if you want it to last.
They are great little motors, I have restored 3 of them.
George"
 
"Ah....I had already organised

"Ah....I had already organised a manual (on CD) here in Australia - which has just arrived....
Thanks for the info on the gearcase. I'll check the oil and the compression ratio this afternoon....thanks !

I've looked around, and it seems that parts are getting hard to get ! Although carby/points/etc seem to be available.

If the compression is down, is it still worth fixing ? I can't see any new rings available - are there rings suitable from any other engine Are there oversize options available? - or new sleeves (does it use sleeves?).



Otherwise, what are my options ?

Sorry for all the questions !

regards,
ted"
 
"Hi Ted:
Just about everythin

"Hi Ted:
Just about everything you need is available,(pistons, rings, gaskets etc.) try ishopmarine.com .Probably if it hasn't been beat to death, all you would need is a gasket set and piston rings or you could try to find another 33 for a new powerhead etc. sometimes it's a better option. They were a very popular motor and didn't change that much over the years.This is a picture of my recently restored '63 28, which is the 33's predecessor and looks identical.
26069.jpg
1963 Evinrude 28
 
"Wow, that looks gorgeous ! &#

"Wow, that looks gorgeous ! (a far cry from the somewhat tatty one I have...). I took it out on the weekend, and it seems reasonable - I've still got to tune it (points etc), but new plugs, fixed fuel leak, and new impeller got it going. I've convinced myself that it is worth working with.

Although I've put in a new impeller, the inside of the housing is a bit pitted - I've been told that this will shred the impeller quickly. A local machine guy will whip up a stainless steel insert, or I'll look for a new one soon !

thanks for your help and info,
regards,
ted"
 
"Stay off some local made SST

"Stay off some local made SST insert, it will make severe corrosion dammage in both the remaining water pump housing and probably even the gearcase."
 
"Just machine the housing and

"Just machine the housing and re-establish the correct depth.No problem with the stainless, after all the drive shaft and propshaft are stainless."
 
"Stainless is not just stainle

"Stainless is not just stainless!!!!!! There are different alloys! Do it wrong, and You have a battery running."
 
"I'd forgotten about the p

"I'd forgotten about the possibility of electrolysis, thanks for that ! - no inserts for me
"
 
"Yes, but not A5 sst!
All SST

"Yes, but not A5 sst!
All SST screws in the OMC/Evinrude/Johnson are 'neutral' when it comes to galvanic corrosion compared to what You get in Your local hardware or boat shop. Yes, they may corrode as well, but far less and mainly because the alu alloy used in casting varies alot depending on amongst casting methode and demand of the parts."
 
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