Help Please! 35 Johnson wont start

[pabloescobedo96]

Hello, I have a 1979 35 Johnson outboard model# 35EL79A
Well I had my engine overheat and die on me. The reason it died was the coilpacks on the block melted, and the platic coated the ground for the coilpack so it had no continuity. Well I replaced the coils and it started and ran fine until it overheated again and melted the new coilpacks. well I found the simple problem was a clog in the water line. so I cleared the line put new coils on it again. Now I have good spark at the plugs and plenty of fuel. But it will not run. I compression tested it and it appears to have 30 psi cyl 1 and 35 on cyl 2. I am not sure of the specs but this seems low to me. although they are within the 5 psi window. Anyways I shot oil in the cylinders to check the rings and exact same on compression. It will give me a pop once in a while but wont run. Any help would be greatly appreciated.

 

[tashasdaddy]

Re: Help Please! 35 Johnson wont start

pull the cylinder head, and see if you have a blown head gasket, 99.9 % yes, or worse damage. replace the impeller and the thermostat at the same time.

 

["G"]

Re: Help Please! 35 Johnson wont start

I compression tested it and it appears to have 30 psi cyl 1 and 35 on cyl 2. I am not sure of the specs but this seems low to me.

Pablo you are 100% correct, 35 PSI for a compression is not enough to make your outboard run. You got it to "POP" after injecting oil into the cylinders because you were able to draw fuel into the cylinders as well as compress the fuel/air mixture into a flammable gas.

The fact you overheated it twice is cause for concern. Melted pistons is most likely the reason for the bad compression. A bad head gasket will cause a similar reading on compression but typically not that low. It's not impossible though so good luck!

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

Thanks guys for the words of wisdom. My guess would be maybe the headgasket is leaking in between the two cylinders causing the almost even pressure loss on both cylinders. Does that ever happen? Well I'm going to pull the head tomorrow. I am an auto mechanic and don't know alot about two strokes. But At first glance it appears to be pretty simple to simply pull the head. Is this the case or is there more to it?

 

[Daviet]

Re: Help Please! 35 Johnson wont start

Just pull all the head bolts and have a look. Let us know what you find.

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

Pulled head in 5 minutes. Will post pics in 5 more minutes!

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

Well as you can see it did just as expected. Except for the part where it torched the head inbetween the cylinders. It also melted in the same way on the block but the sleeves are still perfect. Only the aluminum in between the sleeves melted. So now my question is where do I go from here. How much is a new head or how much can I mill it? I have a good welder that can weld aluminum and then mill it if needed. I think the block will be ok because the sleeves are still perfectly flat. I could be wrong though...

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

Here is a pic of block for reference

When I look at the gasket it appears in between the cylinder it only really seals on the sleeves where the metal rings of the head gasket rest if you can picture what im saying.

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

well a new cyl head is around $450. Finding a used one is a pain. so I will have it welded and milled flat again. It is melted about .050-.060 which im sure would up compression way too much if I just milled it flat without welding.

As far as the block goes this is where I really need your guys opinion. Welding and milling the block is NOT an option, since the sleeves and block are different metals it would just get all screwed up. I will not buy a new block even though I'm sure that is the only Correct Solution. I would buy a new motor before I did that.


But now the pending question is. What is your wager on the head gasket holding up if the sleeves are still perfectly flat and the head is perfectly flat knowing there will be a void in between the two sleeves???

 

[G DANE]

Re: Help Please! 35 Johnson wont start

Used heads are not that rare, they show up on ebay often, at small prices. I might even have one floating around, but i'm in Denmark. I would fill the gaps around the bores in block with JB weld and sand it. Cant go anywhere. If you chose to weld the head, be aware it will warp ( bet it already is ) Dont mill it much - in fact you should only mill enough to straighten it, or it will be unuseable - not much extra space, when gasket is off a lot of them touches pistons.

 

[Daviet]

Re: Help Please! 35 Johnson wont start

You will need a new head. By the parts breakdown, a new head is about $340.00, a used one should be a lot cheaper. JB weld will work for the block, as G DANE suggested, just make sure that you sand it flush.

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

I found a good used head for about 60 dollars. so that will be better than fixing mine.

On the jb weld Idea I like it but makes me a little nervous.
What if the jb weld expands a lot when hot or starts to melt/burn creating a gas pocket.

I found block filler, like used on race cars to fill water jacket for strength. Maybe that would work better. or maybe not.

 

[HybridMX6]

Re: Help Please! 35 Johnson wont start

The JB Weld has been used by many others on the board with no issues, so I would go with that if it were me. I would not leave it an empty space, it's going to make a weak spot in the sleeves and cause failures there as well, creating a much more expensive repair than it is now.

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

Alright then I will use jb weld and sand flush.

What should I do on torque specs for the head. the bolts seemed not so tight when I removed them.

I was thinking about a quarter turn till she strips. or should I find the specs
And should I use any locktite or anything

 

[Daviet]

Re: Help Please! 35 Johnson wont start

Before you use the Jb weld, clean surface very good, it will work fine. The reason the bolts were loose is because when the head overheated it expanded and compressed the head gasket. Do not use locktite on bolts, torque to proper specs, warm engine to operating temp, let cool and retorque, thats all you need to do.

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

Allright! this is gonna work good. My used head is on the way via ebay for $50.00 with 10.00 shipping. I am having a hard time finding specs on head bolts. Anyone have a clue?

 

[samo_ott]

Re: Help Please! 35 Johnson wont start

Interesting thread. Head bolt torque is 158-192 in lbs on the '79 35hp.

Let us know how it all turns out

Oh, and you'll want compression to be 80# or more on each cylinder to get 'r running.

 

["G"]

Re: Help Please! 35 Johnson wont start

You really sneaked by disaster. If the rings are still loose on the piston you could obtain pressures of 80-90#'s. A large flat file will do lots for you but that block does need a fix. If you really clean that up good the JB weld will most likely work for you. If it doesn't you haven't lost much, just get it welded and milled.

Happy for ya... just be careful that you don't overheat again. Fate tempted twice usually doesn't render a lessor result.

 

[pabloescobedo96]

Re: Help Please! 35 Johnson wont start

You really sneaked by disaster. If the rings are still loose on the piston you could obtain pressures of 80-90#'s. A large flat file will do lots for you but that block does need a fix. If you really clean that up good the JB weld will most likely work for you. If it doesn't you haven't lost much, just get it welded and milled.

Happy for ya... just be careful that you don't overheat again. Fate tempted twice usually doesn't render a lessor result.

I think it will work out. I'll let you guys know how it goes.

Yes I did sneak by disaster. Melted pistons would have really messed my day up. I think I was wrong in saying it was a plugged hose causing overheating. I haven't looked yet but I bet the impeller is fried. I was running my motor in a very shallow river dragging though sand for a while before this happened. I have done this many times with no problems but I'm sure it caught up with me.

The reason I thought it was just a plugged hose is when I got the boat home I pulled off the water hose that goes to that little pee nozzle deal and blew it out with compressed air and a piece of crap popped out. But the funny thing is I have never noticed water coming out of it before anyways, water just usually sprays out the exhaust.

So is that pee nozzle just so you can make sure water is flowing or is it critical?