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Johnson 115 timing issues

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Dsmrossi

New member
I have a late 80’s Johnson 115 that hasn’t run in about 4 years. I got a great deal on the boat, but can’t figure out the motor.

I have the throttle wide open with the fuel disconnected. I’m putting my timing light on the top stbd cylinder and when my timing light flashes, the marks are on the opposite side of the flywheel, nowhere near the point. In other words, the flywheel is 180 degrees or so out when the timing light flashes.

I’m stumped...

Reason I’m trying to check timing is because motor idles rough and pops heavily, sometimes seizing up when it pops. Trying to sort this out before I put her in the water
 
You need your light on the top port cylinder. Left side as if you were sitting in the driver's seat. The popping is probably carb related if it sat 4 yrs they need to be gone through completely. Get new kits and give them a good cleaning. Also replace the waterpump.
 
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flyingscott said:
You need your light on the top port cylinder. Left side as if you were sitting in the driver's seat. The popping is probably carb related if it sat 4 yrs they need to be gone through completely. Get new kits and give them a good cleaning. Also replace the waterpump.
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Port side?! I’ll give that a shot
 
Dsmrossi said:
Port side?! I’ll give that a shot
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Whaaattt?????? Top right....#1.

Look for crossed (swapped) plug wires on the right side, look for swapped orange primary wires on the same side.

Orange/blue is top cylinder (#1), orange is bottom (3).

Heck, for that matter check the port side too while you are at it.
 
daselbee said:
Whaaattt?????? Top right....#1.

Look for crossed (swapped) plug wires on the right side, look for swapped orange primary wires on the same side.

Orange/blue is top cylinder (#1), orange is bottom (3).

Heck, for that matter check the port side too while you are at it.
Click to expand...

I'll check the wiring, however I don't believe they are crossed as the motor runs and sounds normal when the throttle is opened up, which is why the timing light readings are driving me nuts. It's almost as if I had a distributor in a car 180 degrees out
 
Dsmrossi said:
80’s Johnson 115 - hasn’t run in 4 years - throttle wide open, timing light on the top starboard cylinder - my timing light flash marks are on the opposite side of the flywheel, nowhere near the point.

Checking timing because motor idles rough and pops heavily, sometimes seizing up when it pops.
Click to expand...

Sitting 4 years (approx)... Carburetors are fouled, clean and rebuild as needed. Be sure to manually clean the four high speed jets (4) located horizontally in the bottom portion of the float chambers, way in back of the drain screws

Pops and seizes?... Hopefully you mean that the engine pops and stops running. Indicates running lean (fouled carburetors)

No need to have the throttle open (Old wives tale).

Check timer-base under flywheel... sticking in retard position? Not up against the rubber spark advance stop?

Timing is set by flywheel alignment with the crankshaft via the flywheel key. If out of time, the engine would not run at all. Full spark advance setting is set via the timing stop screw that has the rubber stop on its head.
 
Do a cylinder drop test and find out which cylinder is dead. While idleing pull a plug wire and quickly put it back on the engine should respond the same on each cylinder.
 
A compression test is the first thing to do on that motor.---A sheared flywheel key throws the timing out.----You can not determine a sheared key with a timing light either.-----The timing is set at the factory and normally needs no adjustment.-----Unless of course an owner has the " lets adjust this and see what happens " repair approach, and now it needs to be reset to factory new.
 
joereeves said:
Sitting 4 years (approx)... Carburetors are fouled, clean and rebuild as needed. Be sure to manually clean the four high speed jets (4) located horizontally in the bottom portion of the float chambers, way in back of the drain screws

Pops and seizes?... Hopefully you mean that the engine pops and stops running. Indicates running lean (fouled carburetors)

No need to have the throttle open (Old wives tale).

Check timer-base under flywheel... sticking in retard position? Not up against the rubber spark advance stop?

Timing is set by flywheel alignment with the crankshaft via the flywheel key. If out of time, the engine would not run at all. Full spark advance setting is set via the timing stop screw that has the rubber stop on its head.
Click to expand...

Both carbs look impeccable, but I ordered 2 rebuild kits regardless.

The primaries are wired correctly, so it does seem like a fueling issue, but i still don’t understand the timing light picking up the #1 almost 180 degrees out from the timing marks.

You can check if the key has been sheared off by setting #1 at TDC and seeing if the casting on the flywheel lines up with the electric starter, right?
 
Welp... def not a sheared key, marks lined up and piston 1 is dead nuts at the top.

Going to rebuild carbs and go from there.

I also have to replace the cheap plastic log style fuel “manifold”. I split it when removing the carbs. I’ll make something more sturdy from a piece of tubing
 
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