tommyb6273
Cadet
- Joined
- May 28, 2012
- Messages
- 8
i have a 1990 larson with a 1983 merc 185 v6 3.8L. I blew the motor last summer and picked up a low hour one over the winter. I was told it was a 4.3 but after running the numbers i found out it was a 83 3.8L 185hp with 4 barrell. I bought it complete and fully assembled all i had to do was connect the 2 harness plugs and a couple wires.
I installed it and the day i started it for the first time it fired right up so i was happy because i never heard it run when i bought it.
The first time on the lake it ran great no issues
second time it ran fine to the fishing spot about a 2 mile run. anchored for a while then fired it up to head back. it fired right up but when i went to hit the gas it ran like crap it wouldnt get above 2200 rpms and was bogging bad.
I changed the water fuel seperator, no change
I changed the coil and the bog was gone so i was happy, atleast i thought i was.
I shut it off to turn on the muffs so i could run it. when i went to start it, it cranked for like 20 seconds before it would start normally after running, it would fire right up in like 3 seconds. I shut it off and it did the same thing i would have to try several times to get it started.
Once it starts it runs fine no bog sounds good gets right up on plane. but if i shut it off its hard to start. it dosent matter if it sits for 2 minutes or 5 hours it still has a long crank time.
I checked all my connections on the coil and there all fine.
I started to think maybe bad coil out of the box so i did some testing.
I checked the ign switch and thats working fine
i checked the shift interupt switch and that seems ok
i checked power at the pos side of coil and that is good with key on and cranking. i checked the neg side of coil and it had power coming from it. correct me if im wrong but that cant be right. i took my test light and connected it to the neg side of batt and neg side of coil and it lite up.....
i disconnected the 2 purple wires from coil and connected a wire to pos side of coil, i had a buddy crank the motor and i touched it to the batt and the boat fired right up. we did it a couple times and it started everytime.
I reconnected the purp wires and it cranked forever before starting.
i disconnected the gray tach lead from coil and still the same thing.
Questions i have are,
because its a 90 boat that had the 4.3 with thunderbolt iv ign and now it has the 3.8 with the points ign is there wires in the harness that need to be changed or disconnected? both ends of the harness ends have the same amount of connections.
why is there power coming from neg side of coil?
i still have my 4.3 ign system coil, dist, wire harness etc, can i replace my 3.8 points setup up with my 4.3 thunder bolt setup?
why would just changing the coil give it a starting issue?
thanks for the help!!!!!
I installed it and the day i started it for the first time it fired right up so i was happy because i never heard it run when i bought it.
The first time on the lake it ran great no issues
second time it ran fine to the fishing spot about a 2 mile run. anchored for a while then fired it up to head back. it fired right up but when i went to hit the gas it ran like crap it wouldnt get above 2200 rpms and was bogging bad.
I changed the water fuel seperator, no change
I changed the coil and the bog was gone so i was happy, atleast i thought i was.
I shut it off to turn on the muffs so i could run it. when i went to start it, it cranked for like 20 seconds before it would start normally after running, it would fire right up in like 3 seconds. I shut it off and it did the same thing i would have to try several times to get it started.
Once it starts it runs fine no bog sounds good gets right up on plane. but if i shut it off its hard to start. it dosent matter if it sits for 2 minutes or 5 hours it still has a long crank time.
I checked all my connections on the coil and there all fine.
I started to think maybe bad coil out of the box so i did some testing.
I checked the ign switch and thats working fine
i checked the shift interupt switch and that seems ok
i checked power at the pos side of coil and that is good with key on and cranking. i checked the neg side of coil and it had power coming from it. correct me if im wrong but that cant be right. i took my test light and connected it to the neg side of batt and neg side of coil and it lite up.....
i disconnected the 2 purple wires from coil and connected a wire to pos side of coil, i had a buddy crank the motor and i touched it to the batt and the boat fired right up. we did it a couple times and it started everytime.
I reconnected the purp wires and it cranked forever before starting.
i disconnected the gray tach lead from coil and still the same thing.
Questions i have are,
because its a 90 boat that had the 4.3 with thunderbolt iv ign and now it has the 3.8 with the points ign is there wires in the harness that need to be changed or disconnected? both ends of the harness ends have the same amount of connections.
why is there power coming from neg side of coil?
i still have my 4.3 ign system coil, dist, wire harness etc, can i replace my 3.8 points setup up with my 4.3 thunder bolt setup?
why would just changing the coil give it a starting issue?
thanks for the help!!!!!
