1988 johnson 60 puked a spark plug out!!??

[Buickmike]

I have some previous posts about my seemingly cursed 60 horse....i finally got the idle problem solved and decided to take it to the lake last weekend.
Short story recap....carbs fully rebuilt, fuel pump rebuilt, all new fuel lines from tank to motor including bulb, compression tested 120 for all 3, stator and coils checked ok, spark gap checked, new plugs, misc wires repaired with new connections, basically this whole motor has been gone through and confirmed in good shape and working properly by a certified marine mechanic. Last work performed was setting idle in a large tank as i couldn't get the boat in water near the mechanic. It ran beautiful...idled nice, went into forward/ reverse to high rpms without a hiccup. Then i take it to the lake and it starts and idles fine...throttle to the first detent and it falls on its face and stalls.(existing and ongoing issue) After numerous restarts i get my dad to pump the bulb while i press the primer in...it stumbles a bit and then WHAM.....we're flying!!!
kept it at around 3/4 throttle for about a minute then as soon as i throttled down it stalled. It became very difficult to start again. I limped it back to the dock and tried to start it again, there was a bang sound, then it sounded like an exhaust leak. I was so pissed off i just said f-it and trailered it and went home.
Forward to home....take the cover off and the bottom spark plug is layin in the case with the wire still attached...i can look/feel in the hole and it is almost smooth....wtf?...
- I don't have the old plugs to check and see if there was a previous heli-coil repair that came out with the old plug.
- i can thread the new plug in but it doesn't get tight and kinda flops around.
- could something like this have been the cause of my inability to get the motor to run past idle in the water( the original reason i got the carbs rebuilt)
- all testing both in and out of the water has been with a portable gas tank and my built in aluminum tank(no difference with either tank hooked up)
- i'm getting to my wits and wallets end with this motor.....any ideas or input gurus of iboats?
Thanks in advance

 

[82rude]

I would of said fuel pump issues but you say its been rebuilt.So fix spark plug issue by heli or new/used cover.Then id look at the connections for fuel.Both male and female.Ihad issues years ago and all it was ,was the connector from the end of tank hose to the motor.The cyl head cover is a 35 dollar part.Now that I see its a vro motor is it still hooked up?The reason I ask is I just remembered a good friend of mine had a 50hp of around the same year with the same issues you had and it never ran right for years so he gave up on it and it sat for ever.Long story short he took it to a good mech and within 1/2 hour he had a excellent running motor.The mech immediately scraped the vro and all his running /not running issues went away.Reading your post has jared my memory about his issues and the solution.

 

[jakedaawg]

K, I'll bite. There is no way that a vro pump caused a plug thread malfunction. They get blamed for a lot because people don't take the time to understand and maintain them but the vro is not the issue here.

Time for either a helicoil or a new head.

 

[82rude]

I was addressing his other issues the heli coil is obvious.Unlees I'm seriously misreading his post he,s been having ongoing problems .Why not spend the 35 bucks and get a new cylinderhead cover start there but keep in mind what I said about my friends issues and solution.The first vro,s were crap and more than not they were discarded until the better versions came about.Hope its just the spark plug issue and I'm totally reading it wrong which the way things have been going today its entirely possible .

 

[Buickmike]

vro is disconnected....we did find a minor air leak at the connector on the motor. Part of the repair work to hard line the fuel right from the tank to the motor..no quick connects in the system. I have looked for a used head for this motor....like finding a rainbow unicorn in a field of skittles...lol..

 

[82rude]

you can get the cylinder head cover from several dealers.. on line for like 35 bucks.maybe even here on iboats but if not I will post a link to one.

 

[jakedaawg]

The plug screws into the head, not the cover. I could be wrong but I don't think so. As for the vro I guess I read it wrong.

 

[flyingscott]

Detonation will throw a plug out as will over tightening look at the piston to make sure of no damage. Is it timed right link and sync done correctly spark plugs in it are the correct ones. The plugs screw into the head itself NOT the water jacket. How is that head hard to find uses the same head as the 1985 and earlier 70 hp you have the 49 CID block. If you can't find a head repair the hole with an insert MUCH better than a helicoil. It sounds more like a link and sync issue because once it's running it runs good a bad link and sync will cause a stumble. Also do you have the original carbs on that and what manual are you using.

 

[82rude]

The plug screws into the head, not the cover. I could be wrong but I don't think so. As for the vro I guess I read it wrong.

t​You could be totally correct I cant tell by the diagram one way or the other.Buickmike a 75 hp is supposedly the same not the 70 per your other post.If you have no success ive had good results with helicoils and done properly they will last forever.Keep us posted on your efforts and eventual success.

 

[Buickmike]

flyingscott......thanks for the crossover info on the head..i will widen my search. Link n sync and timing done with a timing light as per manual. I don't know which one was used, i just assumed it was a factory manual. As far as i know the carbs are original, they have the non adjustable idle jets. The plugs are the recommended champions as per the manual again. I did shine a light in the hole and the piston looks fine. The plug didn't look like it had been doing much though. The other two were a nice toasty light tan and the one that popped was clean.

 

[flyingscott]

t​You could be totally correct I cant tell by the diagram one way or the other.Buickmike a 75 hp is supposedly the same not the 70 per your other post.If you have no success ive had good results with helicoils and done properly they will last forever.Keep us posted on your efforts and eventual success.

That is wrong information the 49 cid 75 hp has it's own specific head cannot be used on the 60. The 60 and 70 share a head in the 49 cid block. The 60 hp was made to use the leftover parts when the 70 hp went to the 56 CID block in 1986. The spark plug inserts to repair the hole are many times better than helicoils I would try that before replacing the head.

1985 evinrude 70 hp head Part# 0323681
1988 evinrude 60 hp head part #0323681
1988 evinrude 75 hp head part#0323682

Do a lot of research before taking advice some of it can be wrong

 

[82rude]

My apologies I was looking at the cover which stated that a 87 75 was the same.sorry for the wrong info.Thanks for catching that flyingscott!

 

[Buickmike]

UPDATE....
I put the insert in the head instead of helicoil.....took her out tonite......it runs!!....everything seemed pretty good. The only issue it had was when i would idle for more than around 10mins it would start to slowly die....then i would have to blip the throttle to keep it running.also it would be a little boggy coming out of idle....once it sputtered a few times it would be fine. The impression i get from it is like a cat hacking up a fur ball..lol...
Any ideas on what this may be caused by?

 

[jakedaawg]

The silencer should have a little hose nipple in the bottom of it. Is there a hose plugged into it that then goes to a nipple on the manifold beneath the bottom carb?

 

[flyingscott]

What is your idle speed in gear, could be lean

 

[Buickmike]

the return hose from the air box is connected. I'm not sure about idle speed. The mechanic set it in a barrel and it was around 800 to 850 ish in gear. Yesterday at idle when it warmed up i had to adjust the idle up a bit to get it to stay running. At the first detent on my throttle i got a gps speed of 3mph. My boat is a 16ft K&C Thermoglass with an aluminum tank built in the stern. I had around 65litres of fuel in it yesterday. It takes a little while to plane out because of that tank i'm guessing but i got 27mph in a light chop at wot.

 

[flyingscott]

A link and sync not properly done will cause that and so will a low idle speed and you cannot set your idle speed in a barrel. Get a tach and when the motor is completely warmed up set the idle speed in gear.