Poping from exhaust

[lindsey]

I have a 73 85hp evinrude when it is on the hose it pops out of the exhaust and breather idles down comes back up then it does it again every 5 to 10 sec its more out of the exhaust than the breather. When i raise the cold start lever and get the rpm up to about 1400 its not as bad.When i go to the landing it does it not as bad then when i go run it for a little while btw it runs perfect getting on step and at cruising speed bring it to idle its fine runs perfect.These are the things ive done so far rebuilt both carbs changed all fuel lines and put good s.s clamps new spark plugs water pump. Decarbed the motor. Any thoughts would be greatly appreciated

 

[Faztbullet]

Re: Poping from exhaust

These engines need back presure to operate correctly, run the engine in a barrel or backed in at ramp for adjustments. The lean spit you have could be a syn & link problem but since it clears up after running it could be upper/lower crankshaft seals are hardened from age and the heat softens them forming a better seal, or a intake/carb gasket leaking.

 

[ezeke]

Re: Poping from exhaust

You may have bent a reed.

 

[lindsey]

Re: Poping from exhaust

is there a way to check if the seals are leaking maybe by spraying something around them idk just a thought.If its a reed i would have to take the intake plenum off i suppose?Thanks for the reply

 

[ezeke]

Re: Poping from exhaust

You can see the reeds pretty well with the carburetors off.

 

[emdsapmgr]

Re: Poping from exhaust

Check the timing to make sure the flywheel key is not broken. Also, check to see that you have all 4 plug wires on the correct spark plugs. If the power pack was recently replaced, verify that the power pack is correctly wired to each coil.

 

[lindsey]

Re: Poping from exhaust

thanks for the replies. Sent the motor to a outboard mech today the bottom carb was leaking in excess air in to the throttle shaft bushings problem fixed