77 Johnson 115 won't hole shot without choke

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

Was thinking about this some more. Almost every other minute it seems.
Anyway, is there some place the crankcase could be prone to developing an air leak causing the lean out symptom I'm experiencing?
Just seems odd that it ran so well and just having the carbs rebuilt to stop leaks and putting on new fuel lines and control cables would be causing all this.
Really, seems like the motor just coincidentally started developing a vacuum leak someplace that I can't readily see or hear. Maybe there is someplace specific I can look or be directed to if these engines have a known spot or possible area that could cause this kind of issue. The reason I say this is because I launched from up in a canal when I got it back and had to putt along at idle speed for almost half a mile, so if something was ready to blow out, it had time. By the time I got to where I could go full speed the motor had been running for at least ten minutes. Not trying to detract from any other possibility, but seems like benefit of the doubt to the carbs since it seems the fuel pump is off the list. I will still pull the carbs back off as soon as I can. Tomorrow I'll call and see if the shop can remember if the jets were changed out. Kind of doubt they'll remember, but worth a shot.
Any thoughts? Thanks for any input.

 

[fireman57]

Re: 77 Johnson 115 won't hole shot without choke

Mu eye is fairly untrained at this but it looks like a late 60's to me. Someone better than me will come along or you can start a new thread on what year it is and post these pics.

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

A 60's vintage? WOW! that would really be something. I have no idea if the motor cover is original (I would bet it is not original to this specific motor). For sure, the motor was painted with white rattle can paint, but it is originally white. The cover has had vinyl lettering and the SeaHorse stuck on it, not original, just generic tape they put on them at this shop. You can almost make out the original stripes at certain angles. I have seen the pattern on other motors over the years and the color is white overall, with blue fade stripes if that is any help. The shop that I bought it from rebuilt engines, so very likely this one is put back together from several motors and as many different years. To me it looked just like the 85hp that was sitting next to it, but I wanted the most power possible and got this one. But, it is possible it's only an 85hp motor with 115 tape on the cover. LOL, I would not be surprised if that were true....

Any ideas of where to look for vacuum leaks aside from vacuum hoses. Those have been replaced.

 

[fireman57]

Re: 77 Johnson 115 won't hole shot without choke

You can have an air leak at a fuel connection. Bad gasket from carb to block.

 

[emdsapmgr]

Re: 77 Johnson 115 won't hole shot without choke

The engine is a 1973-1977. Could be a 92 cubic inch 85/100 or a 99.6 cubic inch 115. It has the belcrank shift system on it as well as the single vernatherm thermostat system. Someone has put 83 or newer carbs on it. While it may run with them, you need to verify that they are jetted correctly to supply required fuel. You may want to pull the carbs down and see what size throats they are and what the jet sizes are inside. For instance they could be 90 hp carbs on a 115 block... Interesting that someone has put dual trim solenoids on the starboard side of the engine (Only one required...) You should be able to verify the real block information from the core plug on the top of the block-see picture.

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

This is what I needed to read. Thank you, thank you! I will pull the carbs off and break them down on my next day off. I do have dial calipers, so a measurement of the throats is easy. I will also get the jets sorted out. More and more, it seems that this must be the problem.
It will run, but idles with sneezes and pops and puffs of smoke. Hole shot and Top end is completely gone. I did call the dealer and they could not tell me if they had replaced the jets or not.

I need to get that special screw driver so I can replace all the jets all at once. Would not happen to have a pic or part number for that screw driver handy?

My block has been painted over, but I will locate and report back with those numbers tonight. That is some good info.

Not too surprised this motor is mix match of parts. Seriously, it ran great until I took it in for tune up. Even the spark plugs are different. The ones I had in it were not original, but they were the same design that I bought it with. A flat electrode surface. Sorry, don't have the model of them handy, but I will report back with it tonight as well. The dealer replaced them with Autolite 2634's which allowed the motor to idle, but after a few minutes on the water, the electrodes were being ever so lightly closed which may indicate a worn out motor or higher compression pistons is my guess.

The solenoids are regular automotive and work great! I have been asked about them a few times. They were on it when I got it.

Thanks again, I am looking forward to getting this motor back out on the water.

Thanks
Greg

 

[fireman57]

Re: 77 Johnson 115 won't hole shot without choke

You want to run champions in these engines and not surface plugs but the old fashion kind.

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

emdsapmgr: I could not locate the plug on top of my motor that you provided previously. Should it be on the front top, rear top, under the flywheel, behind the air intake??
I just don't seem to find anything that resembles what you indicated.

fireman57; My plugs are Autolite 2692 the flat kind without a projecting electrode.
Not sure if the Champion version was available at the time.

 

[fireman57]

Re: 77 Johnson 115 won't hole shot without choke

These engines were built around Champions. I would use them as the surface plugs don't do well in these engines. If it ran fine before then I don't see where even if the carbs were wrong to start with that they would have anything to do with the problem.

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

I see your point. I was trying to show that my engine may have higher compression pistons due to the plugs used. Unfortunately, I did not get my old plugs back after the dealer did the tune up. All I can remember is they were the flat electrode type.
Kind of confused that the plugs installed by the dealer are Autolites. Would of thought the Champions might have been installed by the dealer if they are the preferred plug.
Sorry, I am not familiar with the plug you recommend. Can you post a pic or a part number please.

If not the carbs, then I must go back and re-check all the hoses again. Must still have a vacuum leak or a gasket that has gone bad.

Thanks for the help,

Greg

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

Fireman57, the old style plugs that have the electrode sticking out the end will not hold a gap. After a few minutes of running, the electrode get pushed down, effectively closing the gap and no more spark occurs. Once that happens, the engine stops running. Of the two spark plug styles, the one I use is the only one that will work and has ever worked. It was the plug that was in the motor when I bought it. Champion makes one, they just were not in stock the day I got new plugs.

Thanks
Greg

 

[fireman57]

Re: 77 Johnson 115 won't hole shot without choke

You should be running Champion QL77JC4 in that engine. If the pistons are hitting the plugs then you have something totally bad going on.

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

Thanks Fireman57.
Funny thing is that I once bought plugs based on model/year/HP and was sold plugs with the electrode sticks out style.
Then, when I pulled the plugs in the engine to swap them out, found the flat type (motor was running good, just thought it would be a good idea to swap out the plugs because I had been running it for several months and the outside of a couple plugs were rusted looking). So in went the new ones and within a few minutes the engine died. Pulled the new ones out, put the old ones back in, and she runs great.
My guess, is the guy who rebuilt the motor likely used high compression pistons and or domed topped pistons and so the clearance between the sparks and the top of these pistons requires the flat plugs. Or, yes my engine is way past worn out and I really should scrap it and not spend any more money on it. Kind of crazy to take it to the dealer, ask for a determination on wether to spend time and money on a motor. I was told they would first do a compresson check, seems like I was told they were all around 135-140, maybe that is bad, seems alright, was told because it has good compression it was worth tuning up.
Motor was running really good before I took it in to have leaky carbs rebuilt. Essentially, the carbs needed new gaskets. I needed new control cables as the ones on it were original and cracked. Not by me, I try to take care of things. But the motor and controls were 1977 vintage, so they had a few miles under the belt already.
Now, I get the boat back, assured it is in top shape and find out when I get a chance to use it that it runs awful. Make it to shore, pull a plug and see the old style with the electrode sticking out. Go down to AutoZone get the flat type, put them in and away I go, just no hole shot and it runs inconsistent, sneezy and snorting at idle.
So, here I am tying to explain what I have which is apparently and Frankenmotor. It is understood that really no help is possible because unless someone takes it apart to see just what it was built with, there are too many possibilities to figure out. Had the old guy who built it still been around, I would likely not be having this trouble since he probably knew every part that was compatible with every other part on these motors by heart.

I appreciate the help guys. I really do thank you all.

Take care and all the best,
Greg

 

[fireman57]

Re: 77 Johnson 115 won't hole shot without choke

Have you done a compression check lately?

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

Nope, good idea though. I will check it personally as soon as I get some time.

 

[emdsapmgr]

Re: 77 Johnson 115 won't hole shot without choke

The core plug with the serial number on it sits on the top of the port cylinder (that's the passenger side.) Likely it's been painted over a few times, so you may need to clean off some layers to really read what's stamped there.

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

Thanks, I should have a chance to look for it this weekend.

I'll report back as soon as I can.
Appreciate all the help,
Greg

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

Found it.... Unfortunately, it is covered from view by the ignition coil bracket. The bolts on the bracket did not seem to want to turn. I have sprayed some liquid wrench on them and will try again this weekend

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

Got the coil bracket off, unhooked the wiring harness, plug wires, etc. and had a good look at the plug on top of port side cylinders. Mine is not domed like the one in your photo, but rather cupped, no writing or stamped nomenclature, just smooth as glass. It does not appear to have ever been touched as there are no tool marks and the factory paint is intact. The plug is about the size of a quarter. No layers of paint to peel off as this area of the motor is still factory paint and it just has no inscriptions of any kind. Just looks like a freeze plug to me..

I suppose, I will just go back through it all again, I have obviously missed something along the way and or the dealer missed something when they had it. I did talk to the dealer a week ago and he wants me to bring it back in so they can look at it, and I may do that, but I am going to look at it all myself first. I have the manual and have been reading through it. Motor runs, just not pulling up full power, miss firing at idle, sneezing, and just seems to have all the symptoms of lean jetting, or an air/vacuum leak, pinched fuel line....??
Found this to read through as well over the weekend.

http://forums.iboats.com/johnson-evinrude-outboards/top-secret-file-updated-8-1-2012-a-299680.html

I have not done the compression test yet as I keep forgetting to grab the gauge and my boat is not at my house right now.
Still want to test compression and I'll let you know what that looks like.

 

[Greg Boswell]

Re: 77 Johnson 115 won't hole shot without choke

All 4 cylinders comp checked 125psi

still waiting to get a free and dry day to pull carbs off and take a caliper reading...