BigWeakSauce
Seaman
- Joined
- Apr 4, 2020
- Messages
- 50
Posting my experience here to hopefully help someone out as I almost tore my carb apart for a rebuild unnecessarily.
This is a 1974 Mercruiser 165 I/L 6. After fixing a cooling issue my boat suddenly wouldn't start, it had been starting just fine after I finished repowering her so I was at a loss (New starter, starter relay, alternator, spark plugs, cap, rotor, points, condenser, ignition coil, battery, fuel pump, some new wiring). Discovered no fuel pumping into the carb and almost took it apart for a rebuild on the spot which would have set me back several days if not weeks and we have good weather finally on the way here in CLE. Started right up when spraying starter fluid so I thought I had a clogged jet or something.
Put gas in first, to be sure she was full!
I decided to work backward instead just to be absolutely certain something upstream wasn't the culprit, SPEND THE TIME DOING THIS! Took the fuel line off the carb and fuel pump to check for a clog, line was clear. Put an empty orange juice jug on the open end of the fuel line and cranked away, no fuel coming into the line. So now I was concerned my bran new fuel pump blew out on me. Took the fuel line off the inlet and unmounted the pump from the block, as soon as my gasket came free of the block my pump lost pressure and fuel spilled out so I thought the pump had to be ok. Checked filter, looked fine. Then held the pump over the side of the boat and manually compressed the lever and a healthy bit of fuel shot out, stuck my finger over the inlet while pumping the lever and felt good vacuum, pump was OK! Now I'm freaking out a bit because my fuel tank is inaccessible without tearing into my paneling and flooring and I'm concerned I have a clogged fuel line. Stuck my hand pumps into the fuel line (brass fitting still in the end of the line) and pumped vigorously with no luck extracting fuel. Tried to siphon via my mouth and couldn't get anything but fumes, tasted great... Somehow when sucking on the hose I heard a faint bit of air flow escaping my hose around the brass fitting. Pulled out my knife, cut the hose at the fitting, stuck the fitting into the firm hose where I just cut it, started to suck from there and IMMEDIATELY fuel started flowing. Plumbed everything back up and the engine started almost immediately!!!! A tiny little air leak compromised my entire system, and the repair was free, excluding my time and frustration.
So long story short, check everything before committing to unnecessary repairs!! Good chance a mechanic charges me for a carb rebuild, new fuel pump, and a few hours of labor had I brought her in.
Good luck out there and I hope this post helps someone save some big headache.
This is a 1974 Mercruiser 165 I/L 6. After fixing a cooling issue my boat suddenly wouldn't start, it had been starting just fine after I finished repowering her so I was at a loss (New starter, starter relay, alternator, spark plugs, cap, rotor, points, condenser, ignition coil, battery, fuel pump, some new wiring). Discovered no fuel pumping into the carb and almost took it apart for a rebuild on the spot which would have set me back several days if not weeks and we have good weather finally on the way here in CLE. Started right up when spraying starter fluid so I thought I had a clogged jet or something.
Put gas in first, to be sure she was full!
I decided to work backward instead just to be absolutely certain something upstream wasn't the culprit, SPEND THE TIME DOING THIS! Took the fuel line off the carb and fuel pump to check for a clog, line was clear. Put an empty orange juice jug on the open end of the fuel line and cranked away, no fuel coming into the line. So now I was concerned my bran new fuel pump blew out on me. Took the fuel line off the inlet and unmounted the pump from the block, as soon as my gasket came free of the block my pump lost pressure and fuel spilled out so I thought the pump had to be ok. Checked filter, looked fine. Then held the pump over the side of the boat and manually compressed the lever and a healthy bit of fuel shot out, stuck my finger over the inlet while pumping the lever and felt good vacuum, pump was OK! Now I'm freaking out a bit because my fuel tank is inaccessible without tearing into my paneling and flooring and I'm concerned I have a clogged fuel line. Stuck my hand pumps into the fuel line (brass fitting still in the end of the line) and pumped vigorously with no luck extracting fuel. Tried to siphon via my mouth and couldn't get anything but fumes, tasted great... Somehow when sucking on the hose I heard a faint bit of air flow escaping my hose around the brass fitting. Pulled out my knife, cut the hose at the fitting, stuck the fitting into the firm hose where I just cut it, started to suck from there and IMMEDIATELY fuel started flowing. Plumbed everything back up and the engine started almost immediately!!!! A tiny little air leak compromised my entire system, and the repair was free, excluding my time and frustration.
So long story short, check everything before committing to unnecessary repairs!! Good chance a mechanic charges me for a carb rebuild, new fuel pump, and a few hours of labor had I brought her in.
Good luck out there and I hope this post helps someone save some big headache.
