1977 Johnson 115 hp ETL Idle Question

[Charlie5653]

Hello, I have a johnson 115 hp 1977 that was my fathers. He passed and the boat set for 12 yrs. I finally got around to getting it out and seeing if it would run. Here is what I have done and I'm confident I'm so close, hopefully with a bit of help with some folks knowledgeable about this antique my family can enjoy it once again. Thanks in advance.....
(1) removed plugs and disgarded
(2) put 2 cycle oil in each cylinder and rotated engine by hand. ( not locked up, Outstanding!) was so happy....
(3) ordered service manual for engine
(4) Removed 2 carbs and soaked for 2 days (actually they were pretty clean when I took them off) -- installed carb kits in both, new welch plugs, needle / seat and float. float is level with carb body when the needle is closed per manual.. I'm 100% confident in the carb cleanings ( every passageway is clear )
(5) since carbs were off and it was easy to get to the the gear linkage bolt I figured it was a good time to pull bottom 1/2 and install new water pump so I did that...
(6) reinstalled carbs
I think this is most everything I did prior to begin testing the motor on muffs. Testing went as follows:
oh, also I did pull the intake and check the leafs. no daylight in them, all 4 look brand new....

(1) compression test - 3 cylinders have 116 and #4 has 108
(2) spark test - all cylinders 7/16+ spark gap test. Spark is not the problem, I have plenty of spark
(3) installed new OEM spark plugs @ .040
(4) rigged a small external tank with 50 to1 fuel and new prime bulb.
(5) engine started right up, Idles at roughly 1100 rpm but idles rough
(6) mixed a can of seafoam to 3/4 gal of gas oil mix and ran through on muffs. took around 1/2 hr
(7) checked timing on dry land (removed plugs and grounded wires, advanced timing to the stop at full throttle. High side timing shows 24 degrees which seems to be good from what I have read. Engine calls for 28 degrees in water...

I have a lake close to me so its easy for me to get it to the water. I understand the basic principal of the exhaust pressure in the water.

so here is what it does now
when I go to the lake Hi side is fine, engine runs 5100 rpm's smooth as silk.
It only idles at 450 rmp and I am unclear on how to get it up to around 750 or 800? The engine I feel is so close to being perfect because it will actually run for extended times at only 450 rpm's. but as it always goes, every time I go to put it back on the trailer it dies at the worst time!!! lol

So my main question is , should the butterflies in the carbs stay completely closed to get the 800 rpm idle? I have adjusted and adjusted on the low side timing and the throttle cable coming from the controller with no success. I just feel like I'm missing something .

Sorry for rambling, I just wanted to answer most of the obvious questions.

Thanks in Advance, Charlie

 

[Charlie5653]

Also, All fuel lines are new with new fuel pump.

 

[interalian]

Time to adjust the throttle stop and cable. Did you do link/sync per the manual when you put the carbs back on?

 

[Charlie5653]

Thanks so much for your help. I have read this link and sync prob 20 times and its just not sinking in yet. but yes I have tried. I'm actually reading it again right now. I'll do my best tomorrow to simply take it step by step. I can tell you that the main scribe mark on the cam lands dead center on that roller when I kick the controller back to neutral with no pressure on the butterflies (they are fully closed)
When I took the carbs off, I didnt have to remove the screws linking the carbs together . The long pin simply popped out of the top carb that linked them.
I did check to ensure both carb butterflies work in unison and they both close at the exact same time as best I can tell

should the butterflies remain closed as the engine idles at around 800?

 

[racerone]

The flutterbys are closed at idle.------But they really are not closed.-----A 2 stroke needs fuel and the all important oil.----There are holes and or cutouts in the throttle plate to allow air and fuel in.-----Idle RPM is controlled with timing !!

 

[Charlie5653]

Closed, Thanks so much... yes, the butterflies have a small notch to draw air right above the welch plugs and 5 or 6 tiny tiny holes to draw fuel from the welches.
So tomorrow I know to keep the butterflies closed at idle and work that lower timing/idle screw.

Thanks again. I'll post back after on it tomorrow

 

[Charlie5653]

Update, pouring the rain here today but I'll still make it to the lake sometime today and have made progress....

link and sync is done. with muffs on I was able to increase the idle to around 1100 rpm however, it did require taking the adjustment screw to its limit. (hoping its not drawing air from the crank gaskets. top or bottom O ring or center gasket on crank case. Is there a way to do a leak down test for that? idle timing is 4 degrees, sound right?

​​​​​​​Thanks in advance, Charlie

 

[Charlie5653]

Too much rain, didnt make it to the water today.

Does anyone know if advancing the idle screw all the way to its limit is a indication of another problem? All the videos I have watched showing this engine running (which is many) shows the idle screw around 1/2 way of its limits.

So I now have the idle spark firing as early as the adjustment will permit. I guess the lake test will tell the tale.

Seems to me the timing curve will be extremely short

Cheers and thanks for any help, Charlie

 

[racerone]

Remove bypass covers to inspect pistons and rings.------Your compression numbers are not encouraging.

 

[Charlie5653]

116? wow. what should they be? I cant find anything in the manual regarding this.

I've been told it "should" run ok with 100 to 110 as long as any one cylinder is not more than 10% lower. Is this bad information?

Thanks for your help, Charlie

 

[racerone]

Are you going to remove bypass covers to inspect ?----Cost you a few pennies for new gaskets.-----Post # 1 mentions you did a lot of work.-----Motor still has issues.-----More inspection needs to be done !

 

[Charlie5653]

Yes I most surly will, I think thats a great idea and observation. My question was what should the compression be for a 1977 engine to assume it will run? I was also told on a 2 cycle engine the number is not as important as the percentage difference?

105 / 100 / 105 / 100 should be ok.. but 125 / 120 /125 / 100 not good (because of 10% difference)

I'm simply asking for your advice to ensure I was not given bad information from my local marina

Thanks for your help, Charlie

 

[Charlie5653]

Also, I more thing..... It was suggested to me last night to start the engine on muffs ( it starts so so easy, less that 1/2 a crank every time when warm) and squirt a bit of fuel or starting fluid very carefully around the top crank seal and both sides of the engine where the crank housing joins to listen for the rpm to bump up.

Thoughts on doing this?

I'm here because I'm not a pro, I'm not a mechanic, I'm just trying to learn and save a few bucks. Any advice is much appreciated in my outboard 2 cycle 101 crash course !!!

Thanks Again.....

 

[racerone]

I am very familiar with this 1977 engine design.----I can rebuild one without looking in a manual.----Take those bypass covers off to have a look.----There are problems with your engine and it should not be hard to determine exactly where.

 

[Charlie5653]

Racer I have taken out the bolts for the cover but it still seems really tight. I didnt want to pry on it to much because I'm unsure if the only thing holding it on is those bolts ( I would assume those bolts are all that hold it on )


I'm just in uncharted territory here and the manual is no help with this to me.

should I just tap on them with a bit more force?

Thanks so much for your help !!

 

[racerone]

Put screw driver between the covers.----Pry one loose and leave it in place then pry the other loose.-----After that procedure the 2 covers come off.

 

[Charlie5653]

Pic, so you know im in the right spot...

 

[Charlie5653]

ok, thanks headed back out

 

[Charlie5653]

You have my full attention !!!
Here is the pic of 1 and 3 --- I did do another compression test this A.M. because I wanted to be more accurate to inform you. #1 has 128 lb #3 has 124 lb

 

[Charlie5653]

this is #3