6 HP Evinrude - head gasket?

Went and looked at a couple of motors a guy had. Ran compression on them.Wound up buying the 5.5 1960 Johnson for 60 frosties and rebuilt the carb. She runs but haven't water tested yet.

To the question. He has a 70's 6 HP Rude that had 30# on the top cyl and 0 on the bottom. Talked to the local Marine guy and he said they are know for blowing the head gaskets,not smoking pistons and he'd put a bet that was the deal with this one.

Anyone else familar with this as a common problem? If so I'll grab that motor too for the same price and repair it. Thanks

The early head gaskets did not have a fire ring and were prone to burning through. I would also bet that is the case.

Well, it is a gamble? If you buy the motor for $60.00 and the head is really messed up and not just the head gasket...then you can part it out on ebay. If the lower unit/gear case is good, you could easily get $45 to 60$ for the lower unit. Look on ebay and get an average price range for each of the parts that you sell. If you are not greedy, you could easily double your money if not more. Carb if in good shape could go for 25 to 35 dollars, the motor cover 15 to 20 dollars......get my drift.

But if you get this motor and the head gasket is blown and you replace the head gasket and get compression numbers hopefully greater than 70's then you have a motor you can work with.

But the million dollar question is, why did the head gasket blow in the first place.....over heated due to poor are no cooling of the head. So, if you replace the head gasket and have decent compression numbers, you need to investigate why it blew in the first place or you will back to where you started quickly.

Here are a couple of links that will help you on your way.

https://www.tinboats.net/forum/viewtopic.php?f=4&t=14047

Good reading here!!

https://www.sschapterpsa.com/ramblings/OMC_6hp.htm

Parts diagram.( you can change the year)

https://www.boats.net/parts/search/BRP/EVINRUDE/1972/6202D%201972/parts.html

Good luck

Thanks for the reply. And awesome links.(I had found your link for Marshall the other day and already printed the manual out.
Good link to the article on the small OMC motors.

Going to head out this weekend to the property and give the 1960 5.5 HP Johnson a try out. (I rebuilt the carb with a new kit,and freash plugs) Will see how it does on the 12' Tin Skin flatbottom. Anywere to get the small plastic adjusting knob for the carb.(Low Speed?)

Think I will pick up the 6 HP 'Rude next week. I'd like to have it because it is a little bigger and also Newer Styling. Not sure of the year (didn't copy the serial # down)

Check this link out for possible parts and parts diagram for your 1960 5.5hp Evinrude

https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1960&hp=5.5

The 6hp Evinrude looks to be late 1960's to early to mid 1970's. Good dependable little motors. I have 2 of them.

The 5.5hp should be run on 24:1 ratio as well. It still has plain bearings on the crank ( I just had one apart). Just remember, we have never seen a two stroke fail from too much lubrication! You won't notice more smoke with todays lubricants and plug fouling is not an issue with that ratio.

Pappy said:

The 5.5hp should be run on 24:1 ratio as well. It still has plain bearings on the crank ( I just had one apart). Just remember, we have never seen a two stroke fail from too much lubrication! You won't notice more smoke with todays lubricants and plug fouling is not an issue with that ratio.

Click to expand...

Doh! #-o Wish I'd seen that Friday. The OMC dealer told me it ran a 50:1...$#&%*@

I was running Amsoil Domonator at a 50:1. Fired it up Saturday and just made a short runs(150 yds) up the cut trying to get the highs dialed in (it wouldn't get out of it's own way) and picked up a chatter like the flywheel was loose.So stopped and checked ,all was good. came back later to try again and after about 50 yards...Clunk! Haven't tore it apart yet but pretty sure it lose the bottom rod. Locks up when you rotate it and no Piston going in and out. Double Doh! #-o #-o

Of course with not knowing the history,could have been abused alot.

Nope, pretty much as long as they have plenty of lubrication they can be abused pretty hard. Those little gems just don't make enough horsepower to kill themselves! Well the good thing is that there are plenty of later model 5hp and 6hp powerheads that will bolt right on to that midsection and accept the carb, ignition, etc. Just make sure the donor has the three bosses on top for the three mounting points on the recoil starter. Fire the OMC dealer that told you the oldies can be run on 50:1 or ask them where the factory documentation is that supports it!

Thanks for all the input. Sorta solvled the problem. Giving it to a friend at the river for spare parts for his 2 matching ones. He set me up with a real nice 78 7.5 mercury that is a real nice runner. moves the 12 footer along real nice.

This boat has always in the past just been my shallow water marsh Duckboat,and always just ran old fixed up motors on it. But now running the river,really need something that won't strand me.

Going to throw a new pump impeller in it,and new plugs just for giggles.