bleedblue94
Petty Officer 1st Class
- Joined
- Oct 11, 2010
- Messages
- 272
1983 johnson 175 v6 sea horse
i have had this motor for 2 years and when i got it it would not idle right. eventually fixed it and had over a year of nice smooth operation. slowly it developed an issue where occasionally on hole shot the motor would bog down. youd hit the throttle and it would rev and then the rpms would just drop like the motor was falling on its face. if you pulled the throttle back the motor would not die and you could rev it in neutral and clear it out. minor inconvenience.
than suddenly i take it out one day recently and it is just running horribly. i cannot even get it to idle. i find that the top carb had a faulty float needle and was dumping fuel out the bowl vent. i remove all three carbs and rebuild them. they all look fairly good and clean but they were prob due for a rebuild anyways.
once the motor is put back together i have a miss at idle. i suspect a lean sneeze bc if i bumped the choke the rpms would come up and generally the miss would go away. now you would assume i messed something up when doing the carbs or putting everything back together, so i proceed to remove the carbs again, open them up, again clean all jets and passages and verify everything. once i put the motor back together i have the same issue. then while running the motor and listening to the idle it every so rarely sounded like it would drop a cylinder and eventually die out. awesome.
compression test comes back good.
i proceed to test the ignition system and find that cylinders 246 jump spark properly, but 135 do not. i swap in known good coils and have positive results where all cylinders are jumping spark. i realize one powerpack is slightly cracked so i know i have to replace it (these were old originals anyways), and if you replace one you have to replace both. new packs show up today so i go and clean all engine grounds and install the new packs and have the same miss. i use an inductive timing light which shows consistent fire on all cylinders, and NO cylinder dropping out when the motor misses. also, now when it misses if i bump the choke the rpms do go up but the issue does not necessarily go away, it still remains in a faint way. i remove the plugs and 135 seem to have more black on them than 246. i test the spark on the 7/16 tool and i have the same issue: 246 jump 7/16, 135 do not. i flip the power packs and have the same issue, i change the stator leads around and have the same issue. (same issue meaning 246 jumps 7/16 gap, while 135 do not)
now i have to wonder would a bad or weak switch box take out all three of the coils i had just swapped in???
i am now looking at spending $200 on coils bc i just feel i should change these all and keep the good ones for spares. if i order these coils and they do no work than what should i be looking at? i recently put on new plugs and plug wires so im not sure where else to be looking now other than coils.
is there another electrical component besides the power pack that would have taken out the coils? i dont want to be buying parts and wasting money only to have more coils burn up.
swapping the stator leads and having the same spark results should eliminate any concerns of timer/stator issues and the fact the issue did not follow the switch box rotation should point at coils only now correct? anyone disagree?
now if the ignition issue is narrowed down to the coils, let me get back to the miss, is there any special way to tell the difference between a lean sneeze or just an ignition miss other than using the choke and seeing if the issue stops temporarily with the added fuel of the choke? im so incredibly frustrated at this point and i dont know what i am missing here....
please help, i will promptly reply and update this post
this is a priority for me bc i am also suppose to be closing on a new lake front property next week and would like to have my boat running when i close
i have had this motor for 2 years and when i got it it would not idle right. eventually fixed it and had over a year of nice smooth operation. slowly it developed an issue where occasionally on hole shot the motor would bog down. youd hit the throttle and it would rev and then the rpms would just drop like the motor was falling on its face. if you pulled the throttle back the motor would not die and you could rev it in neutral and clear it out. minor inconvenience.
than suddenly i take it out one day recently and it is just running horribly. i cannot even get it to idle. i find that the top carb had a faulty float needle and was dumping fuel out the bowl vent. i remove all three carbs and rebuild them. they all look fairly good and clean but they were prob due for a rebuild anyways.
once the motor is put back together i have a miss at idle. i suspect a lean sneeze bc if i bumped the choke the rpms would come up and generally the miss would go away. now you would assume i messed something up when doing the carbs or putting everything back together, so i proceed to remove the carbs again, open them up, again clean all jets and passages and verify everything. once i put the motor back together i have the same issue. then while running the motor and listening to the idle it every so rarely sounded like it would drop a cylinder and eventually die out. awesome.
compression test comes back good.
i proceed to test the ignition system and find that cylinders 246 jump spark properly, but 135 do not. i swap in known good coils and have positive results where all cylinders are jumping spark. i realize one powerpack is slightly cracked so i know i have to replace it (these were old originals anyways), and if you replace one you have to replace both. new packs show up today so i go and clean all engine grounds and install the new packs and have the same miss. i use an inductive timing light which shows consistent fire on all cylinders, and NO cylinder dropping out when the motor misses. also, now when it misses if i bump the choke the rpms do go up but the issue does not necessarily go away, it still remains in a faint way. i remove the plugs and 135 seem to have more black on them than 246. i test the spark on the 7/16 tool and i have the same issue: 246 jump 7/16, 135 do not. i flip the power packs and have the same issue, i change the stator leads around and have the same issue. (same issue meaning 246 jumps 7/16 gap, while 135 do not)
now i have to wonder would a bad or weak switch box take out all three of the coils i had just swapped in???
i am now looking at spending $200 on coils bc i just feel i should change these all and keep the good ones for spares. if i order these coils and they do no work than what should i be looking at? i recently put on new plugs and plug wires so im not sure where else to be looking now other than coils.
is there another electrical component besides the power pack that would have taken out the coils? i dont want to be buying parts and wasting money only to have more coils burn up.
swapping the stator leads and having the same spark results should eliminate any concerns of timer/stator issues and the fact the issue did not follow the switch box rotation should point at coils only now correct? anyone disagree?
now if the ignition issue is narrowed down to the coils, let me get back to the miss, is there any special way to tell the difference between a lean sneeze or just an ignition miss other than using the choke and seeing if the issue stops temporarily with the added fuel of the choke? im so incredibly frustrated at this point and i dont know what i am missing here....
please help, i will promptly reply and update this post
this is a priority for me bc i am also suppose to be closing on a new lake front property next week and would like to have my boat running when i close
