1957 35 hp johnson issues

[BlackoutBill21]

I have this motor that Ive been restoring. So far I've resealed the lower unit, put a new carb on it after rebuilding it, and installed the helicoil kit to fix the stripped spark plug hole.

On the water it idled ok, but never got to top speed. I've included a youtube video for reference, It sounds like it might be knocking too. I haven't tested the compression yet but thats coming later today.

My question is, what would make the adjustment carb needles not work properly. AT one point I had them both closed with no sputter or stalling from the engine, My suspicion is bad compression, bad condensors, or a points adjustment.

I haven't had the flywheel off yet because I had spark from day 1. Was wondering if you guys had a place to start first.

https://youtu.be/APHQvhCGifk

 

[kbait]

Sounds like it’s running on one cylinder. Check compression, check spark.. needs to arc 1/4” from lead to ground. If those are good, do a cylinder drop test (pull one plug wire off at a time and run). If pulling each plug wire off plug makes the motor slow but keep running, you have a fuel delivery issue or bad gas. If pulling one of the wires makes no difference, and pulling the other one kills immediately, the first cyl tested isn’t firing (fouled plug, bad spark, low compression, leaf on reed plate not sealing (behind carb)..
Good luck!

 

[BlackoutBill21]

I will start there when i get home! thanks!

 

[F_R]

ALL 1957 Johnsons have bad coils unless they have already been replaced. Yes, even if it has spark. That is the first place I would have gone.

 

[BlackoutBill21]

Bad coil AND SPARK? That’s news to me! Lol. If they aren’t cracked do I keep them?

 

[flyingscott]

If you have the original coils toss them out and while you are in there replace the points and condensors.

 

[F_R]

Bad coil AND SPARK? That’s news to me! Lol. If they aren’t cracked do I keep them?

I guess you might call them the Great Deceiver. They sure have fooled a multitude of people.

 

[racerone]

Just picked up a 66 model 6 hp.----Of course I popped the flywheel off on first inspection.-----Found 2 nice new coils.----Old , old condensers but new coils.

 

[BlackoutBill21]

Candensers are in the mail. I happen to have 2 new coils lying around too lol didn’t get a chance to test compression today. Tomorrow for sure.

 

[oldboat1]

would be tempted to pull the head, and see if there is any damage visible. Is the helicoil seated properly -- plug reach not excessive. Would check the piston top in that cylinder for any damage. Believe the oem plugs would be J4C or J6C -- would stick with one of those. If the carb needles aren't sensitive to adjustment, it's usually because of a dirty carb -- may need to disassemble and soak again, finish with carb spray.

Look for compression in the 120s and even. Use a 24:1 fuel ratio.

 

[jimmbo]

You said it would run with both the Idle Mixture Needle and the Hi Speed Mixture Needle both closed? Well how is it getting enough fuel to run? High fuel level, due to bad/heavy Float, misadjusted Float, dirt in the inlet needle and/or seat? When you have the flywheel off, inspect the upper crankshaft seal, if it is wet with oil, it probable needs replacing. A leak here would affect the crankcase's ability inhale from the carb, and to exhale to the combustion chamber

 

[BlackoutBill21]

Ok here’s the update and some things unnoticed.

Compression was 120 each cylinder. I was disappointed cause I was hoping that would lead me to the answer.

i pulled each wire while engine was idling. Same result. Engine would bog but stay idling.

the plug hole that I repaired looked ok. The plug however has what I deem excessive oil residue. It wasn’t wet with water but def small puddle of oil.

the other holes plug condition is unknown cause I dropped it in the barrel grrrr

somethings I noticed too... after engine stops, left over water I’m assuming from the power head pours out then ehaust port. Never seen that before.

also if i over squeeze the primer bulb.. after it’s already firm.. gas will pour out the exhaust port.

My my next step is to change the coils and condensers and see if anything changes unless someone sees something else.

 

[BlackoutBill21]

I completely forgot to mention that I converted this To a single line fuel pump. The pump I’m using was 25 dollar one on eBay that has a larger fitting but is rated for 35 hp and more.

 

[F_R]

Gas pouring out the exhaust port when you squeeze the bulb is a glaring sign. Could be:
1. Mashing too hard on the primer bulb.
2. Ruptured fuel pump diaphragm.
3. Assuming it isn't the carburetor overflowing. But if it is, that is another possibility.

 

[BlackoutBill21]

I did over squeeze originally because I had tor down the carb completely and added fuel lines and the new pump. So I wanted to make sure the whole system was primed

 

[kbait]

Ruptured fuel pump diaphram would pass fuel into crankcase when primed..then probably out exhaust (gotta go somewhere), and it would act like it’s running on one cylinder as the cylinder the pump gets its pulse from would be way flooded. Maybe when you mashed the bulb you ruptured it.

 

[jimmbo]

When you installed the fuel pump, is it mounted on the transfer cover, or connected by a hose? If by a hose, you didn't get the hose that's supposed to go to the transfer cover mixed with the hose that's supposed to go to the carb? What did you do with the hose that supplied crankcase pressure to the fuel tank?

 

[oldboat1]

suppose it could also be a carb float issue -- could be upside down. Or maybe a reed valve problem.


compression is good.

 

[BlackoutBill21]

True to my luck... the coils and condensers are NEW. Seems like someone else took a shot at this and came up scratching his head too. Where do I go from here? I cleaned and re adjusted the points, carb coming off now. To re clean and inspect. Is my fuel pump hooked up properly? Fitting line to new pump, pump outlet to carb. Manifold nipple plugged. Other manifold nipple connected to wired circle thing,

is the pump pump I bought too big?

 

[BlackoutBill21]

I just saw the last 2 responses now! I will check the fuel pump diaphragm. I have the hose coming from tank to pump. Pump is mounted onto my side cover plate. Outlet pump hose goes to carb. Lower manifold nipple is plugged, upperone goes to some circle gizmo.