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1998 Johnson 115 question to you...

B

Balder

Contributing Member
Hello, i bought a 98 Johnson 115 a few days ago, when i teststarted the motor it idle at 2000rpm and missfire a little.
When i look in to the carb they all are open about 1,5mm, is that correct ?
They will not close even if i dissconect the linkage......is it any adjustment on the butterfly(i think someone call them that :)
All carbs are cleaned up and the stator/optical eye and powerpack was new not long ago, compression 125psi on all cyl.
Can tell i start it without the controllbox and cables conected if that will help you.
Hope you understand my bad englich....not from usa:)
Hope for some helpfull answers.
 
If you have already pulled on the throttle cable so the idle stop screw has touched the block, you will need to check to see if your motor's cam roller has lined up with the marking on the cam follower. The cam roller must not touch the follower. You can also adjust your optical sensor's setting from high to low. Get a shop manual and read thru synchronization to understand more about the adjustment and setting. All flies should close completely at idle.
Good luck!
 
Ok, i have now ordred a service manual, i actualy think that the previous owner who put new stator, optical eye and also rebuild the motor can have done something with the timing/carb adjustment so the only problem is timing/card adjustment.
Is it possible to put the stator or the optical eye in wrong position so the timing is wrong?
There is no mecanical problem with the motor, all 4 cyl have 125psi compresion.
So now i hope i just need to get it all adjusted......i hope.
Is it around 6 turns you all use on the air screw for the carbs on this motors ?
 
Get the carbs to fully close and then you can adjust the idle air screws. Normally you start with the needles out 1 1/2 turns and adjust from there not sure with that motor. The manual should tell you how to check/adjust timing and sync.
 
The first thing you do is check for true top dead center with a piston stop tool. Disconnect the battery and turn the flywheel to close to TDC on the #1 cylinder use any point on the engine as a reference to the flywheel position. turn the flywheel clockwise abut 30 degrees and then put in the piston stop tool and touch the piston with the stop. mark the flywheel with your reference point then rotate the flywheel clockwise until it touches the tool again and make another mark on the flywheel. measure exactly half way between the two marks is TDC. Pull the piston stop and then rotate the flywheel clockwise and line the center mark up with your reference point and then check adjust the timing pointer to TDC on the flywheel. Pull the plugs so you can turn the flywheel easier and never turn the flywheel counterclockwise. The timing pointer may be good but most all adjustments use that reference point confirm it is correct. Throttle pickup is when the debossed mark on the throttle cam passes center of the follower roller the butterflies on the carb just begin to open that is probably whats holding the carbs open at engine idle. Timing and max timing advance are to be adjusted on the water in forward gear with the engine fully warmed up and under a load same with the final adjustment of the idle air needles.
 
Before you do anything make sure engine is coming out of Quikstart...in Quikstart it will idle high and seem like its missing. When engine temp reaches about 100degrees RPM wll drop and engine will smooth out.Do this in a barrel not on muffs..
Throttle pickup is when the debossed mark on the throttle cam passes center of the follower roller the butterflies on the carb just begin to open that is probably whats holding the carbs open at engine idle.
Click to expand...
Not on a 60 degree motor.... the 1st pic is how it should be set, the 2nd picture is incorrect. Timing is adjusted with a timing tool not a timing light as it optical ignition.
60right.jpg60wrong.jpg
 
Thanks ALOT for many good answer from you, i will now take a look at some issues, i will let you know.
 
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FAZTBULLET......i went out to the garage and had a look at the screw you showed at your pictures, my motor had the screw the wrong way pic 2, i adjusted it like pic 1 and now the carb close totaly.
I will start it up one of the first day and let you know, i am no very optimistic....when it is the wrong way like on pic 2 will it also cange the idle timing ?
This motor had to high idle with a little missfire but not mutch, when i gave it throttle it run perfect...so maybe this "small" adjustment fix both problems...high idle and small missfire....i hope this will fix my problem.
He posted ONE picture of ONE screw....and that screw/adjustment was wrong on my motor....cant wait to try it agein.
 
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Iam very new to this forum stuff. I believe you know what your talking about and if you don't mind I would like to pick your brain a lil about a vro pump.
 
VRO is variable ratio oil injection, Fuel and oil are not premixed in fuel tank,VRO has a separate tank for oil,2 stroke oil is injected into carbs. along with fuel.The pump works off of crankcase pulses. Numerous warning systems are involved.
 
Thx I believe I found away to beat it. I was going straight to carbs with fuel but I believe I still need vro for fuel pump I bought the boat in pieces first I was going with fuel to crank case now I see it's like a air pump.
 
I have done some adjustment on the motor, but impossible to get down the idle rpm, it is 2000rpm.
The carbs are closed.
I have tryed several powerboks.
Tryed finetuning on the air screws, runs best with 6 rounds.
Cleaned and checked all carbs.
The motor have runned for about 1 hour today, normal engine temp.
The "2000rpm idle" is steady but sudently missfire a few seconds before it is back on steady 2000rpm.
Can it be the optical eye ?
What does the motor do with damage optical eye?
What do the motor do with bad stator?
VERY happy if you can help.....
Thanks
 
Are you running this motor on muffs or in the lake? Your idle will be higher on muffs. What is the temp of the motor? Do you have a temp gun to verify the temps. You could have a bad temp sender.
 
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Garrett d said:
Thx I believe I found away to beat it. I was going straight to carbs with fuel but I believe I still need vro for fuel pump I bought the boat in pieces first I was going with fuel to crank case now I see it's like a air pump.
Click to expand...
You need to start your own thread not hi-jack somebody else's. Make sure if you bypass the VRO you are mixing the fuel at 50-1
 
I run it on muffs in the garage, the temp is fine, i can hold my hand on all cylinders 10-15sec.
I have one more of this motors, the other is in use on my trollingboat, that motor idle 1100rpm on muffs and 1-200rpm lower on the water...no problem with that motor.
But my second motor dont run the same way, it feels like the timing is wrong when i hit the starter sometimes, and when it start the idle is 2000rpm with missfire no and then but it dont stop.
The owner before me overhauld the motor with new piston, new stator, timing eye and more, one day the motor just died out on the water for him, i bought it for parts but the motor is way to good for that so i just need to find the problem.
It is a very nice motor so i will not part it up.
 
Your timing may be to high. 10-15 seconds to hold your hand on the motor seems like a long time. Check the temp with an infared gun.
 
I start the motor with a car battery, +cable from battery to the starter, when i put the -cable from the battery on the motor it sparks....is that normal ?
 
Re: 1998 60degree Johnson 115 question to you...

Sorry about all the question....but need help, do i need to remove the flyweel to adjust the timing or can it be done with the plastic linkage/parts on the top of the motor, do i adjust the timing by changing of the optical eye position ?
I have worked alot with snowmobile engines for 30 years but outboard motors i have only USED for my fishing and never had problems with them....
On snowmobiles we turn the stator and the pick up follow but the system on this outboard is new for me.
 
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Get a manual but timing is set with ratchet linkage on top of motor. Leave the high lever alone and only adjust the low one.
 

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Balder said:
I run it on muffs in the garage, the temp is fine, i can hold my hand on all cylinders 10-15sec.
Click to expand...
Holding your hand on a full operating temp engine for 15 seconds sounds a little long. Have you verified the thermostats are installed? It could be the previous owner did not install them when rebuilding the engine. So if the t-stats are missing you have garden hose water running about 55*F flowing freely through the engine. If that is the case, I wonder if maybe the engine is never coming out of fast start mode because it never senses a temperature high enough to decrease to standard idle RPM?

I'd suggest you submerge the lower unit in a barrel and run the engine so it's supplying water on an as-needed flow with the water pump. You might just be over cooling the engine and not ever reaching proper operating temps.

KJ
 
I had the termostat out and had a look at them, looks fine, i will take the termostat from my other motor and test with them, i will also try the watertemp sensors from that engine and try.
Will the motor go as high as 2000rpm if in "fast start mode" ?
 
I have ordred a new optical sensor and hope that will change something.
I see that others have had about the same problems...high idle with missfire/backfire...and the problem was the optical eye.
I have tryed powerboks and coils.
Can it be something with the fuel pump so the motor gets to mutch fuel even if the carbs are completly closed ?
 
Read post#25 again,your engine is running too cold,verify using a digital infrared thermometer on the heads, should read about 160 degrees, when warmed up, Until engines reaches around 100-120 degrees it will not come out of fast start, Quote from another mechanic on this site. Thermostats can be tested in a pot of water on stove, suspend stats in the pot and observe,they will open about 3-4 mm,break out your glasses,their tough to see.
 
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