mthieme
Captain
- Joined
- Oct 6, 2007
- Messages
- 3,270
I wasn't going to post as I am pretty sure I have a handle on this, but with all the collective wisdom.....
I have a 1987 Merc 35. I got this last year and had to replace all the rubber - fuel pump kit, carb kit, fuel lines, filters...it has a new fuel system from tank to carb. It ran great all summer with only an ever so slight rough idle and a very infrequent sputter (usually after idling along for long periods). The big brass idle screw screw (not the mixture adjustment screw) was rough and an ear that holds one of the flaps for the needle was broken off - she still ran like a scorched ape. This new freshly rebuilt carb has the SS screen on top (original did not) and even has a new float. I happened across several other carbs and took the best pieces and made one good one (so I thought). So today I swapped out the carbs. To my amazement she fired right up...for a second. I repeated the process with the same results. This is where I'm at right now. I tried squeezing the primer bulb - same results. Choking does not matter either. Unfortunately I didn't fire her up before swapping the carb...she last ran in late November when the crabbing pretty much ended for the season.
I'm thinking that since it sat in the woodshop - out in the open - it's probably acquired some (much) dust. It had a heavy layer on the outside. If it got inside (dust gets everywhere and I mean everywhere in the shop), it could have affected the needle/seat and/or float, maybe clogged up the little ports, whatever. I anticipate popping it back off, taking it apart and recleaning it.
Other work performed recently include new impeller, changed LU oil, replaced charging stator and rectifier. I don't think any of these items would have any effect on the problem.
I have a 1987 Merc 35. I got this last year and had to replace all the rubber - fuel pump kit, carb kit, fuel lines, filters...it has a new fuel system from tank to carb. It ran great all summer with only an ever so slight rough idle and a very infrequent sputter (usually after idling along for long periods). The big brass idle screw screw (not the mixture adjustment screw) was rough and an ear that holds one of the flaps for the needle was broken off - she still ran like a scorched ape. This new freshly rebuilt carb has the SS screen on top (original did not) and even has a new float. I happened across several other carbs and took the best pieces and made one good one (so I thought). So today I swapped out the carbs. To my amazement she fired right up...for a second. I repeated the process with the same results. This is where I'm at right now. I tried squeezing the primer bulb - same results. Choking does not matter either. Unfortunately I didn't fire her up before swapping the carb...she last ran in late November when the crabbing pretty much ended for the season.
I'm thinking that since it sat in the woodshop - out in the open - it's probably acquired some (much) dust. It had a heavy layer on the outside. If it got inside (dust gets everywhere and I mean everywhere in the shop), it could have affected the needle/seat and/or float, maybe clogged up the little ports, whatever. I anticipate popping it back off, taking it apart and recleaning it.
Other work performed recently include new impeller, changed LU oil, replaced charging stator and rectifier. I don't think any of these items would have any effect on the problem.