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79 Evinrude Rebuild

S

stromzilla

Contributing Member
Can I use my die taps for clea

Can I use my die taps for cleaning out the various bolt-holes or do I need to use Thread Chasers?
 
The assembly is about to begin

The assembly is about to begin...need a couple of tips.

There are a lot of gaskets used in the engine rebuilding process. Should a gasket sealer be used on all gaskets? In rebuilding snowmobile engines we rely primarily on the gasket itself. With the Evinrude teardown it seems as though 90% of my time is spent cleaning the gooy crud off the mating surfaces. Can I get away without using the sealer on the outer water jackets at the heads? Perhaps I need to attend a class called "Gasket Sealer and It's Uses - 101"

Needle Bearing Grease: Used for holding those pesky little critters in place. I don't have any but I do have Petroleum Jelly and Synthetic Bearing Grease. Will either of those work?
 
"i'd opt for the synth bea

"i'd opt for the synth bearing grease, Gasket sealer for me depends on where, I haven't done many full rebuilds, so I cant' say exactly where, but like where the 2 halves of the block I'd say yes but not liberally, more of a thin film, setting time will delay you, and if you forget something then you can have a mess if you have to take it back apart.

Do you know if the engine was rebuilt before ?

The main case obviously is very important, air leaks there and it wont run right, same with the reed area.. an engine is an engine, the gaskets should be enough, but look for areas that might need a little extra "insurance"."
 
"(Gasket Sealers)
&#4

"(Gasket Sealers)
(Usually available at any reliable automotive parts type store)
(J. Reeves)

Do Not use any type of sealer on outboard carburetor or intake manifold gaskets as this would cause blockage of various fuel/air passageways. Also, there are new type gaskets, including head gaskets, which are used through out the engines that are coated with a substance that gives a shinny appearance to them. These gaskets are coated with a self sealer and are to be installed as is.... no sealers! Older style head and fuel related gaskets that are not coated with this substance are to be simply coated with oil.... nothing else.

All other gaskets (hopefully I've not overlooked anything above) should be coated with Gasket Sealer (the type that comes in a can that has a small brush in its screw off cap). This also pertains to some water pump installations that use a gasket between the plate and the lower unit housing.

Marprox Sealer 1000 or OMC Adhesive or Boat Armor Sealer 1000 (same substance) should be used on any metal to metal or metal to plastic surface (such as impeller hsg to plate, and plate to lower unit surface) to eliminate air leaks. It should also be used on the Spaghetti tubing that is used on many powerhead crankcase halves, lower unit skegs, etc. I have found that this substance works quite well on various "O" Rings such as what are found on lower unit carrier and upper driveshaft bearing housings (Note that this substance is obviously not to be used on all "O" Rings). This substance also works quite well in sealing the surfaces between the lower unit and the exhaust housing to which it attaches, eliminating the unsightly water spray between the two after completing a water pump installation.

DO NOT use any sealer on the large "O" Rings that are used on the upper and lower crankcase heads (The housing/heads that slide over the top and bottom of the crankshaft). On those "O" Rings, use only a coating of grease.

The exception of surface to surface contacts pertains to the later model matching crankcase (block) halves (which does not incorporate spaghetti tubing) which call for "Gel-Seal", or any other surface that calls for Gel-Seal. This substance seals in the absense of air, and if called for, must be used. One other form of Gel Seal that can be substituted is "Loctite #518". Nothing else that I know of will do!

I advise against using silicone or permatex on a outboard engine. It simply will not function properly. The exception to this (as per OMC's recommendation), is to use the black Permatex (heavily) on the gasket 306242 which seperates the inner exhaust tube from the exhaust housing on the 1959 35hp and 1960 to 1970 40hp OMC outboards.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay store at:

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"
 
"The crankcase assy halves are

"The crankcase assy halves are back together. Now I'm ready to put the powerhead onto the lower unit...I think. The manual says something about an O-ring that goes on the driveshaft. There is no O-ring in my gasket/seal kit for my driveshaft that I'm aware of. Furthermore in looking at the exploded parts diagram, I did not see anything about an O-ring for the driveshaft and I did not see an O-ring on the driveshaft when the powerhead was removed from the lower unit. What am I missing hear?"
 
"Sorry about that. I get so c

"Sorry about that. I get so caught up in this I forget about the basic info. The engine is a 1979 Evinrude 115, #115999R. I went back to look at the exploded views again and I cannot find an O-ring that goes on the driveshaft. I see an O-ring on the driveshaft that's further down on the shaft but not at the top of the shaft where it goes into the crank. My Evinrude manual talks about it but doesn't show it."
 
"What might the purpose be for

"What might the purpose be for the driveshaft O-Ring? I'm thinking to keep water out of the crankshaft end? As I said previously, there was no O-Ring when I pulled the powerhead off. Could I move forward without an O-Ring by coating both ends with water resistant grease?"
 
Joe - Thank you. If you don&#

Joe - Thank you. If you don't mind me asking...what is the reason for having the O-Ring in the first place? I'm assuming it's to prevent water from getting into the crankshaft end.
 
"u r correct,keeps moisture/wa

"u r correct,keeps moisture/water,out of splines,..however,they quit doing that...either way u r good to go,grease OUTSIDE of splines,none on d-shaft end....also,..coat ur mounting bolts well,w/a sealer...like permatex aviation formagasket,liquid."
 
Thanks guys. Found the O-Ring

Thanks guys. Found the O-Ring in Southfield and it's already installed. Everything got greased. You guys are awesome!!

Today the Powerhead was installed. At this pace I should have it up and running in a few days.
 
That O Ring prevents the gress

That O Ring prevents the gresse from escaping those splines. No grease = water enters splines = rust. The driveshaft splines become rusted tightly to the crankshaft splines which prevents the lower unit from being removed..... really a mess all due to not greasing and installing that one tiny O Ring.
 
"and,....they r not even used

"and,....they r not even used any more..so greasing,is that more important.....i dont think,they have been mfg,for the o ring,..in 15-20 yr,..on all sizes......but,..dont quote me,..somewhere in there."
 
"Well, today is the big day.

"Well, today is the big day. I've got everything assembled except for the carbs and air intake. Should fire it up later this afternoon. Does anyone have any suggestions for the first startup or should I follow the breakin process as spelled out in the Evinrude manual?"
 
"My big day turned out to be a

"My big day turned out to be a bad day. Started the engine and it was right back to where it was before the rebuild. It was stumbling, sneezing, wheezing...you name it. Had a couple of water leaks at the hose but otherwise the rebuild seems to have heldup. Whenever I hit the choke everything smooths right out. So although I'm confident the engine needed a rebuild, the rebuild has not solved the root-cause of the problem I was having. Now I'm going back to the fuel system and I'm wide open for suggestions."
 
"Well.. if you hit the choke a

"Well.. if you hit the choke and it smooths out, means one or all the carbs are lean.. see if pumping the bulb while running helps.. Could be a vacuum leak somewhere too.. (hate to say) Vacuum leaks can be found by spraying Carb Cleaner or Starting Fluid, I suggest putting some fuel mix in a spray bottle and spraying in each carb while running, when you spray in and the engine perks up and smooths out.. that's the carb that's lean.

do your carbs have Idle mixture adjustments? or are they fixed? Could have a couple little holes in the fuel pump diaphram, which if you do the primer bulb test, and it helps, it could be the pump diaphram."
 
I pumped the primer bulb while

I pumped the primer bulb while David had the motor running which should eliminate the fuel pump from the mix.

Also the motor will not idle without a serious stumble/sneeze usually resulting in the motor abruptly stopping. It does run above 1800 and sounds like it is starting to even out.

I personally re-re-built David's carburetors yesterday. I wanted to make sure there was nothing overlooked. Every passage was clean as were all 4 fixed jets. The idle jets for his motor are 27's on one side and 28's on the other (I forgot which went where right now).

We did not try the fuel down the venturi. I thought about it but I think we were at wits end and did not have an appropriate bottle either.

Oddly my motor had the same exact issue as David's does now and after a lot of diligent cleaning it runs great now.

I am leaning toward swapping my carbs for his. We would change the jets over but otherwise they are the same carb. (I think) This might also include running his carbs on my motor to do a double elimination.
 
Just a followup on what is goi

Just a followup on what is going on with David's '79 E115.

I stopped back by David's today. I brought my '79 J100 with me.

First thing we tried was running the motor without the intake cover. I played with the choke plate setting while the motor was running and we achieved a decent idle of roughly 1200 RPM with the choke plate at about 1/4 of the way closed. So the motor needs more fuel at idle to run smoothly.

Then I swapped out one of my older (no longer in use) carbs for his top carb. We swapped the jets as well. The motor ran a little better but it was not anything that would be called "smooth".

Next we swapped both of the carburetors off of my Johnson without changing the jetting. Even without adjusting the throttle rests or hooking up the cables his brand-newly rebuilt motor started up with little to no choke and after a couple minutes of fast idle I backed off the throttle shaft till it was resting on the stop.

The motor idled perfectly at 1000 RPM. No stumbling. No popping. I backed the throttle lever all the way to the idle stop and the motor ran at 650-700 RPM steady. It was amazing!

So what this leaves us with is there is some sort of idle circuit fuel related issue with his carb's. Even though they are what appears to both of us as spotless. Maybe it is an air leak I don't know. We are getting real good at R&R'ing those carbs though.
 
"Once again the root-cause of

"Once again the root-cause of my issue to begin with appears to be the carburetors. However, as stated before, the engine had a leak at the gel seal and upon further inspection during the tear-down, the rings were locking up with carbon...a rebuild was definitely necessary. Can anyone offer up ideas on how to clean the 4 small idle orifices in the throat of the carburetor?"
 
It's finally running and r

It's finally running and running steady!!! I just wanted to give a followup to my thread about the current status of my motor. As it turned out the final issue was the carb-butterflys were not flush at full idle which caused a lack of vacuum and hence a lean runaway idle condition. All is well though and so far I've not found any crankcase assy leaks (gel seal) or any other issues. I checked the plugs today and they're burning nicely. I can idle around the lake without a single fart or the engine quiting. It's a wonderful thing to be able to idle up to the dock like a normal person. Thanks to everyone who contributed to my thread. I learned more than I dreamed of by going through the rebuild process...frustrating at times but I'd do it again in a heartbeat.
 
"Well, my engine continues to

"Well, my engine continues to idle and run as it should. However, I performed a compression test today and was somewhat disappointed...112, 112, 112, 114. The engine has about 5 to 10 hrs since it was rebuilt. Is it normal to initially have a low compression reading after a rebuild? I'm assuming the rings are still seating themselves and the compression will improve or is this wishfull thinking on my part?"
 
JWB - Thanks for the vote of c

JWB - Thanks for the vote of confidence. Based on your response I take is as my cold compression reading is actually a good reading? I was thinking the numbers should be well over 125. Is there any reason to believe the compression will increase or is this it? I was happy to see the readings were close to one another. Thanks again for the feedback. David.
 
My OMC manual says to set the

My OMC manual says to set the timing at 28 degrees BTDC. Is this still the number to go with or has there been an update over the past 30 years that I should be aware of?
 
"Correction: My compression i

"Correction: My compression is 117, 117, 117, 119 as of today. In the previous compression check I didn't open the throttle plates."
 
This thread is a great read gu

This thread is a great read guys. Learned a bunch. Thanks to Joe for that run down on seals and sealants. I'm bookmarking this one!
 
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