I have a 1985 9.9hp Johnson that I was given; don't know the history on it, so I'm more or less doing an overhaul. Anyone have any suggestions on how to get the motor off the mid section without breaking anything? I've got all the bolts removed, but the block is practically welded to the mid section...
Anyone know anything about outboards?
- Thread starter Cougar281
- Start date
Is the lower unit off of it yet? If so then you most likely have missed a bolt or two that is holding it on there.
I don't know much about Johnson Evinrude, I know on our Merc 150 the powerhead has 3 bolts on top and I beileive there was 2 on the lower end as well. it has been awhile though
Yes, the lower unit was off, and no, I didn't miss any bolts; there where six on the underneath and three nuts inside; I finally did get it off. Took some "persuasion". Started taking the water covers off, and what fun... lots of sand and crap inside. Pistons look scored as well. Guess a full rebuild is in order. Yay. At least a full rebuild of a 9.9Hp outboard won't be as expensive as a rebuild on a DMax :rofl:
Anyone have any thoughts on these pistons? The seller seems to be reputable.
Johnson used to make 30 over pistons and rings; If I could get them, I wonder if it would be worthwhile to upgrade to the 15HP exahust tube, then later on if I can find one, a 15HP carb (Mine is one that could be a 9.9 or 15 depending on the carb and exahust tube).
Anyone have any thoughts on these pistons? The seller seems to be reputable.
Johnson used to make 30 over pistons and rings; If I could get them, I wonder if it would be worthwhile to upgrade to the 15HP exahust tube, then later on if I can find one, a 15HP carb (Mine is one that could be a 9.9 or 15 depending on the carb and exahust tube).
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Funny thing there is upon researching it a little further, it appears that until 1981, the 9.9 and 15 use the same exahust, then the 9.9 had the same rectangular exahust, while the 15 had what appears to be a shorter, more restrictive tube, then in or after 87, they went back to using the same tube for both :dontknow:
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need to work those ports some just do NOT remove the bridges between the 3 holes, but raise the tops of the exhaust ports some, and open the bottom of the intake ports some, not much, just a little! 
That baby there got a bit warm I would say. Where did this engine come from? Sure seems to have alot of corrosion for an engine from MO where you only have sweetwater. As for the piston's, I have used him in the past and was happy. I personally would look for a set of coated cast pistons. For the money they seem to hold up the best and last the longest.
These guys show to have SIERRA cast and WISECO forged pistons for it in standard, .020, .030, and .040.
http://www.promarineusa.com/
These guys show to have SIERRA cast and WISECO forged pistons for it in standard, .020, .030, and .040.
http://www.promarineusa.com/
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need to work those ports some just do NOT remove the bridges between the 3 holes, but raise the tops of the exhaust ports some, and open the bottom of the intake ports some, not much, just a little!
FWIW, about the only "upgrade" I am considering doing is converting it to a 15HP motor since it pretty much takes just a carb change.
I got it from my grandfather; It lived most/all of it's life in NY, and AFAIK, has only seen salt water.
Wiseco pistons would be nice, but considering it's not a performace build, I'd say something that'll work and not blow up would be ok for me. If the ones from that fleabay seller are good and will work, I'll go with them at $35ea, although the Sierra's at 55 each aren't horrible (that about the same price as OE near as I can tell).
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I would send the Ebay seller a message and see if he can still get GLM pistons for you. GLM are REALLY nice pistons that are cast and coated, but with a low price. He used to carry em as I bought some from him before.
He said those are GLM pistons. Guess I'll order some up in the next few days; I'll probably get .020 overs so I have another step I can go if I ever need to, unless the bore is bad enough that it needs to go .030.
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Never heard anything bad about GLM's, I was very happy with em in mine. Make sure and replace the lower main bearing while you have it apart and check the others VERY closely for pitting or blueing. Also a pick comes in handy for aligning the rod caps, and you will need an anorobic gel sealant for the case halves and red loctite for the case bolts. As for porting, I wouldn't go much with it. If anything just smooth down the castings some and take off any burrs on the ramps and such. And don't go will in the rod slot areas if you do port, just a cleaning is more than enough.
If you don't have a manual I have one here somewhere that lists bolt torques. I can try and dig it up if you need any torque values. I build mostly V4's and V6's as little engines typically don't wear out unless you overheat em.
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FWIW, about the only "upgrade" I am considering doing is converting it to a 15HP motor since it pretty much takes just a carb change.
guess you've never done any port work on a 2 stroke engine before (2 cycle)
You guess right
Anyway.... New problem: Three of the head bolts broke off flush with the top of the head and the head will not budge. There's about 1/16" inch or so between the bolt and the head on the other three, but the three that broke off, there is zero gap; there's that much corrosion. So far I've soaked two rounds of liquid wrench penetrating oil, and it still won't budge. I've tried prying and hitting it with a 3# dead blow. Any suggestions how to get the head off?
See if you can find you a can of CORROSION BLOCK, this stuff WORKS! Also you need a torch and alot of patience or else you will be in REAL trouble. Whatever you do, do not break the head bolts off any furthur. The best thing you can do is use some CORRSION BLOCK or even some baking soda and water to neatralize the corrsion and then get a torch and heat those areas and let em cool down. Repeat the process a few times and it will come apart.