76 Johnson 115 Misses

[rcollicott]

This engine has a miss at part throttle. Checked plugs and wires with timing light and all is good. But, I always have some oil in the air box in front of the carbs. Could this be some blow back from a reed valve? Could my miss be because of a reed valve even if I don't get a pop in the carbs? Runs great wide open.

 

[emdsapmgr]

Re: 76 Johnson 115 Misses

It wouldn't run great at WOT with a bad reed valve. Those carbs have a tendency to leak oil out the front, esp if tilted up at the end of the day. That excess fuel/oil will get recirculated into the bottom cyl when next started. (through the airbox drain hose.) Likely the engine will smoke and run poorly till that excess oil/fuel gets burned off-maybe a minute or so.

 

[rcollicott]

Re: 76 Johnson 115 Misses

It wouldn't run great at WOT with a bad reed valve. Those carbs have a tendency to leak oil out the front, esp if tilted up at the end of the day. That excess fuel/oil will get recirculated into the bottom cyl when next started. (through the airbox drain hose.) Likely the engine will smoke and run poorly till that excess oil/fuel gets burned off-maybe a minute or so.

Thanks so much for the info! Did not know that about the carbs leaking when engine is tilted. Makes good sense!