84 johnson 115 v4 no power in gear

[Shawsuper]

I've checked comp. Changed plugs and powerpacks. Motor idles fine. But in gear it will go no faster than idle speed. I pulled plugs and checked them one at a time for spark. All good. Here's where I'm dumfounded, while the motor was running, I pulled both plug wires on the port bank and it did not change the running condition of the motor at all. How can the plugs be firing but not hitting in the cylinder. I need expert advice. Forgot to mention, the motor has developed a bad sneeze in low idle that will usually kill the motor

 

[durban]

Re: 84 johnson 115 v4 no power in gear

i have experienced this problem with a 90hp what appears to be a spark when you test it & when you pull the 2 plugs off on one bank it still idled , wot in fact was happening is that the spark was not big & strong enough to ignite the fuel on that bank , check the coils or replace & also clean the earths this solved my problems

 

[Shawsuper]

Re: 84 johnson 115 v4 no power in gear

I have not verified the spark strength. Although the spark didn't look weak. The mechanic who changed the power pack said it sounded like it had a broke Reed. I looked at the reeds best I could when I pulled the carbs off to clean em. I didn't see anything that looked broke. How would I know if I had a broke reed. How would a broken reed affect the combustion in that bank. I've ordered new coils and wires. After the installation of them ill have new coils and powerpacks I hope this corrects the problem.

 

[emdsapmgr]

Re: 84 johnson 115 v4 no power in gear

Either you've got no spark on the port bank, or no fuel to those two cyls. You can perform a simple test. Swap the two power packs. If the running issue moves to the starboard bank, you've found your spark issue. If still no fire on the port bank, I'd try spraying some fuel/oil mix into the port carb throats when idling and see what happens to the idle rpm's.

 

[Shawsuper]

Re: 84 johnson 115 v4 no power in gear

I've thought about my motor and come to this conclusion. If I'm getting spark with the plugs pulled but no combustion with the plugs in the cylinders, has to mean I'm getting no fuel to those cylinders. The lean sneeze I'm getting in low idle supports my theory. I believe I've got a Reed issue. Is there anyway to confirm this without pulling the carbs and reeds? Ill report back tonight

 

[emdsapmgr]

Re: 84 johnson 115 v4 no power in gear

If the engine has a bad reed, usually you will see some fuel spit back out the front of the carb. It will spit back during each rotation of the crank. It's a pretty unusual failure.