1986 20 hp Evinrude ignition ????

[chrisire]

Own a 1986 20 hp Evinrude (CE20TECDC) and it overheated last summer. Replaced water pump and all related components. After that it would idle not to bad, but any attempt to throttle up just caused it to bog down as if the timing was completely out of line. Had tune up and timing set last summer at the start of the season and it ran well up until the overheating. I have replaced the rectifier and the Power Pack. Anything else I should be checking before putting it in the water and looking like the rookie that I am trying so hard not to be. I am fairly mechanically inclined and do have an Evinrude repair manual for the motor. Any help or suggestions related to this outboard would be greatly appreciated.

[boats.net]

check compression. How long did it sit from the time it overheated and the next time you have taken out with the bog (after the repair).

[chrisire]

It overheated and I had to wait 2 weeks for replacement parts. It was back in the water and running 2 weeks after the overheat. Would overheating ruin the rings or cause cylinder damage?

[chrisire]

Sorry I forgot to add that I haven't had it in the water yet since putting on the rectifier and power pack. It just started to overheat. I always watch to make sure water is coming out the visual pee spot. Once it cooled down it fired right back up. No paint blister or anything on block.

[boats.net]

Unless severly overheated, your rings and cylinder should be ok. You could crack a block or head, or blow a head gasket. I am a little confused, you have or have not had it out since the power pack replacement? If it is still overheating, you may need to replace the thermostats.

[chrisire]

I have not had it in the water since the rectifier & power pack replacement. This motor does not have a thermostat.....Correct? If there was a crack in the block would there not be a noticeable flow of water or fuel mix under the cowl somewhere? The compression should not be the same in both cylinders. If it is, does this indicate a blown head gasket?
I appreciate all the help and suggestions that I'm getting. Our local marine shop did the tune up last year, and after the fact I found out they have only 1 licensed mechanic and a bunch of wanna-be's. I had to point out to them to hook up the fuel line so the engine would start after he had been trying for 10 minutes. Basic mechanics, first check fuel then spark!!

[boats.net]

That motor does have a Thermostat (on the top portion of head). You can have a blown head gasket and cylinders show the same or close to same compression. But if you have not tried since the powerpack swap, then you will probably be ok. Check the thermostat for the overheat issue.

[chrisire]

I will change the thermostat just to be sure. Do I need to replace the head gasket as well as the top gasket when pulling the thermostat? From what I can tell, the top end has never been apart. The original paint still covers all the edges of the exposed gasket material and bolt heads. If I am careful to remove the top plate and replace the stat, do I have to go as far into it and replace the head gasket? I know what a thermostat does, but where does this one control the flow of water to and or from? My understanding was that this outboard was a free flow water jacket around the entire block asembly. Obviously I am wrong. Also looking in the parts diagram I can see parts called deflectors that seem to be located in the lower part of the cylinder head...what do these do??? Can you please help head me in the right direction.
I can't tell you how much I appreciate your help. Like I said in an earlier thread, our local marine shop is no help unless you own a large boat with an inboard and have lots of money to throw around.
I'm just getting into boating and loving it, and would like to keep going.

[boats.net]

You do not need to replace the head gasket when changing the thermostat. You should however change the thermostat gasket. Pricing can be obtained from Boats.net - New and Used Boats for Sale, Outboard Boat Motors, and Discount Outboard Boat Parts or by calling the 877-408-1499

[chrisire]

I changed the thermostat. It was completely stuck in the open position. The gasket looked like crap. Did another compression test. 120 on the top cylinder and 118 on the bottom cylinder. I also read on this forum that the plugs should be gaped to roughly 40 thou for a better spark and burn. Is this correct?