TheKodiakWay
Cadet
- Joined
- Aug 2, 2012
- Messages
- 12
Mercury 650 3cyl, serial number 3549871
The motor starts and idles just fine, on the muffs and in Neutral it's perfect. My problem comes when I give some throttle while in gear. If I slowly apply throttle it picks up to a high idle and starts to just bog down, eventually dying if I keep applying throttle. If I slam it from idle to full throttle, it just dies. I found if I play with the choke flaps a bit the motor smooths out and runs fine, if I'm less than cruising (say 3/4) throttle as soon as I open the choke back up it bogs and dies. Now if I'm at or above 3/4 throttle and play with the choke until it runs well, it will continue to run just fine until I shut down. I've gotten to the point I can run the choke from the electric push button, and let off at the right time (just before dying) it spits and sputters a bit, then takes off.
The motor has an unknown history until I got it a few years ago. The old prop had a spun hub, water pump was shot, no vanes left at all. I've replaced those as well as a new fuel tank, and had the carbs professionally cleaned and rebuilt last year. I pulled the fuel pump today and it had a brown oil in the bottom mounting hole. Everything on the inside looked fine however. I pulled the fuel filter which looked clean, but had a couple pieces of stuff in it and was split in a few places.
Now to my questions.
1. What can be causing this bogging dying issue?
2. What kind of rebuild kit should I get for the fuel pump? Diaphram, check valve, both?
3. Is it worth replacing the stock fuel filter, or should I go with something different like an inline?
The motor starts and idles just fine, on the muffs and in Neutral it's perfect. My problem comes when I give some throttle while in gear. If I slowly apply throttle it picks up to a high idle and starts to just bog down, eventually dying if I keep applying throttle. If I slam it from idle to full throttle, it just dies. I found if I play with the choke flaps a bit the motor smooths out and runs fine, if I'm less than cruising (say 3/4) throttle as soon as I open the choke back up it bogs and dies. Now if I'm at or above 3/4 throttle and play with the choke until it runs well, it will continue to run just fine until I shut down. I've gotten to the point I can run the choke from the electric push button, and let off at the right time (just before dying) it spits and sputters a bit, then takes off.
The motor has an unknown history until I got it a few years ago. The old prop had a spun hub, water pump was shot, no vanes left at all. I've replaced those as well as a new fuel tank, and had the carbs professionally cleaned and rebuilt last year. I pulled the fuel pump today and it had a brown oil in the bottom mounting hole. Everything on the inside looked fine however. I pulled the fuel filter which looked clean, but had a couple pieces of stuff in it and was split in a few places.
Now to my questions.
1. What can be causing this bogging dying issue?
2. What kind of rebuild kit should I get for the fuel pump? Diaphram, check valve, both?
3. Is it worth replacing the stock fuel filter, or should I go with something different like an inline?