Tripp Halbert
Petty Officer 1st Class
- Joined
- Jul 30, 2013
- Messages
- 202
Hello everyone,
1981 Mercury 115hp i6 'tower of power' here hooked up to a Glastron CVX-535
We rode out all spring no issues then one day after a long cruise up and down the creek the ol' Merc started shutting off on us close to the ramp. I took it home and played with the carbs, ran it the next day and about 30 min up the creek she bogged down off plane and shut off. I finally got running and had to limp all the way back to the ramp.
Have since been able to get it started but it wont stay running long without the hot-start (idle-shifter forward to increase rpms, not sure the exact name of this?).
Checked:
1. Spark; all 6 firing strong
2. Compression 125 psi all 6
3. Drained lower unit oil, checked for anything locked up or metal shards, etc. All checked out in good standing order and free spinning smoothly.
4. Checked carbs, all seam clean and clear. (when i can get it to finally run with the hot-start, putting my hand over the top and middle carb i get equal hard suction, but the bottom carb feels weak, not sure if this means anything)
5. Fuel lines all in good order, ball pump tight, clean fresh fuel and external/internal filters
6. Finally inspected the fuel pump in which my last post about this engine the new fuel pump kit was the last issue solved that made it come alive and we since put 15-25 hrs on her before this problem arose. The 1st fuel pump diaphragm i replaced initially was slightly torn with a hole in the middle. This time, it is torn in 3 places (pictured below). I believe now the previous owner installed in the wrong sequence. So naturally, i believed it was the correct way and re-installed the same way last time which seemed to work great. I have attached a schematic i found to be the one i needed. I have installed the new kit both the way i had it before and the way depicted in the schematic.
Order installed (incorrect?) - 5, 3, 6, 14, 13, 4
Order according to schematic: 6, 3, 6, 14, 5, 13, 4
The engine seems to give me the same poor results with both diaphragm sequences. How can this fuel pump partially operate in these different scenarios? I hope to understand how it works so i can figure out the problem here. I was 99% sure replacing it would be my fix, but apparently not...or am i missing something??
Thank you guys for any info, look forward to getting this ripper back out on the creek !!!
-Tripp Halbert
1981 Mercury 115hp i6 'tower of power' here hooked up to a Glastron CVX-535
We rode out all spring no issues then one day after a long cruise up and down the creek the ol' Merc started shutting off on us close to the ramp. I took it home and played with the carbs, ran it the next day and about 30 min up the creek she bogged down off plane and shut off. I finally got running and had to limp all the way back to the ramp.
Have since been able to get it started but it wont stay running long without the hot-start (idle-shifter forward to increase rpms, not sure the exact name of this?).
Checked:
1. Spark; all 6 firing strong
2. Compression 125 psi all 6
3. Drained lower unit oil, checked for anything locked up or metal shards, etc. All checked out in good standing order and free spinning smoothly.
4. Checked carbs, all seam clean and clear. (when i can get it to finally run with the hot-start, putting my hand over the top and middle carb i get equal hard suction, but the bottom carb feels weak, not sure if this means anything)
5. Fuel lines all in good order, ball pump tight, clean fresh fuel and external/internal filters
6. Finally inspected the fuel pump in which my last post about this engine the new fuel pump kit was the last issue solved that made it come alive and we since put 15-25 hrs on her before this problem arose. The 1st fuel pump diaphragm i replaced initially was slightly torn with a hole in the middle. This time, it is torn in 3 places (pictured below). I believe now the previous owner installed in the wrong sequence. So naturally, i believed it was the correct way and re-installed the same way last time which seemed to work great. I have attached a schematic i found to be the one i needed. I have installed the new kit both the way i had it before and the way depicted in the schematic.
Order installed (incorrect?) - 5, 3, 6, 14, 13, 4
Order according to schematic: 6, 3, 6, 14, 5, 13, 4
The engine seems to give me the same poor results with both diaphragm sequences. How can this fuel pump partially operate in these different scenarios? I hope to understand how it works so i can figure out the problem here. I was 99% sure replacing it would be my fix, but apparently not...or am i missing something??
Thank you guys for any info, look forward to getting this ripper back out on the creek !!!
-Tripp Halbert
