ttreewalkerr
Cadet
- Joined
- Jul 20, 2005
- Messages
- 13
Basic 4 stroke motor question,, mine happens to be 50hp Mercury for my Pontoon boat.
Well this week i went up for 4th holiday and had time to mess w/ my bogging issue.
I have a bog/miss after 2100 rpm, that goes till 3400, then picks the miss cylinder up,, then bog after 4000 rpm...
Well after running it at 3000 w/ the miss and spraying in gas direct to carb mouth it picked up.. Suprized after i have cleaned these carbs every year and this year did a full rebuild,, still same.
But during this experiment,, i told my son,,, (Remeber, mouths of carbs are exposed due to me spraying gas in w/ suirt bottle to determine problemed cylinder/carb), REV it to Wide open, it did nor bogg to a stop,,,, i had the air box cowl off,, Venture of carbs open,, cover off motor. I was suprized it went WOT..... So we stopped on lake,,, i put on Air box cowl,,,, bogged,,, and fell on its face at WOT.. Took cowl off, ran like a champ,, still misses at 3000 rpm,, but definetly improved.
My question is: WHY ? Why the removal of the cowl that goes to the carb mouths, which is only a slight restriction, would bog this motor down like that ?
for the rest of the week i just left it off, and put the outer cover on the outboard,,, but still why ?
My Riding 4 stroke mower is kinda same,, it can bearly havdle a new air filter,,, slight restriction and falls on its face.
Is there a common element w/ a 4 stroke and air intake restriction issue ?
Awaiting your reply.
Well this week i went up for 4th holiday and had time to mess w/ my bogging issue.
I have a bog/miss after 2100 rpm, that goes till 3400, then picks the miss cylinder up,, then bog after 4000 rpm...
Well after running it at 3000 w/ the miss and spraying in gas direct to carb mouth it picked up.. Suprized after i have cleaned these carbs every year and this year did a full rebuild,, still same.
But during this experiment,, i told my son,,, (Remeber, mouths of carbs are exposed due to me spraying gas in w/ suirt bottle to determine problemed cylinder/carb), REV it to Wide open, it did nor bogg to a stop,,,, i had the air box cowl off,, Venture of carbs open,, cover off motor. I was suprized it went WOT..... So we stopped on lake,,, i put on Air box cowl,,,, bogged,,, and fell on its face at WOT.. Took cowl off, ran like a champ,, still misses at 3000 rpm,, but definetly improved.
My question is: WHY ? Why the removal of the cowl that goes to the carb mouths, which is only a slight restriction, would bog this motor down like that ?
for the rest of the week i just left it off, and put the outer cover on the outboard,,, but still why ?
My Riding 4 stroke mower is kinda same,, it can bearly havdle a new air filter,,, slight restriction and falls on its face.
Is there a common element w/ a 4 stroke and air intake restriction issue ?
Awaiting your reply.