98mystique2
Cadet
- Joined
- Jul 20, 2019
- Messages
- 6
OMC 4.3 432APWXS in a 1987 Fourwinns horizion 170 2 barrel rochester carb
Long story short, someone last year was drunk trying to pull the carb off the engine to rebuild it over winter (it was me). They began removing the big fitting directly on the carb without removing the smaller one that goes into the big fitting and over tightened that in the process to the point it no longer points in the correct orientation without leaking. I can't seem to find the identical parts and what was there is leaking. How do i go about finding replacements OR can I buy an AN fitting inlet to the carb and use a right angle to SS braided line to the fuel pump?
How do I know if a fitting is NPT or other? Are the flares 37 degrees or 45?
Now listing all the fittings in order that I have starting from the carb which is a rochester 2bbl.
Male .8615" od thread 20TPI to female 27TPI
male .396" od thread 27 TPI right angle to female .4465" id 20TPI flare fitting (when tightened normally before messing it up it was at about 7-8 o'clock)
1/2" 20TPI fitting over .3215 OD/.251ID SS flare line
1/2" 20TPI fitting over .3215 OD/.251ID SS flare line
Fuel Pump
Long story:
Had issues last year where when the gas tank indicated half full the boat would sputter and not want to run at full throttle. First checked that I actually had gas (I did) Changed the fuel filter and it worked better for maybe a bit longer until it did the exact same thing. Also noticed the fuel filter bracket was cracked so I pulled that off and welded it back together. we'll come back to that later. Did a bunch of troubleshooting with no results. Pickup tube was good, replaced the fuel lines encase they were soft and collapsing, checked the drainback ball valve thing, all looked good. decided to clean the carb over winter and messed up the fitting as I said above where i mangled the fittings. Guess what, get to half a tank an still doesn't work. Think ok well only thing left is the fuel pump maybe it's not flowing enough once it has to lift the gas higher. In the process of pulling lines to get a part number off the fuel pump i notice some odd coloration just above one of the flares. Sure as heck the SS line from the filter to the pump is cracked. vibration and hanging from the previous owner must have cracked it. It never leaked (always under suction) and was behind the fitting so it was never noticed but you'd get enough suction and it'd be letting air in. Anyway I got a steel line and bender and that kinked like a cheap hose. So I got some nickle copper line and hand bent it but the flare tool was kinda junk so the double flare leaked a bit and I have to re do that, I may try to flare another piece or just grab some more ss braid line. But yeah with the upper carb fitting leaking I pulled the hardline from the carb to the pump and noticed some corrosion on the SS line near the carb so I kind of want to replace that and it might have gotten banged up from my previous errors.
Where does one go to get new fittings, will the clocking be the same if i buy something similar or do i run the risk of being in the same situation even if I do find a 27tpi to 20tpi flare fitting 90?
Any issue with going with a SS braided AN and using something like this https://quadrajetparts.com/adapter-i...ing-p-368.html
Long story short, someone last year was drunk trying to pull the carb off the engine to rebuild it over winter (it was me). They began removing the big fitting directly on the carb without removing the smaller one that goes into the big fitting and over tightened that in the process to the point it no longer points in the correct orientation without leaking. I can't seem to find the identical parts and what was there is leaking. How do i go about finding replacements OR can I buy an AN fitting inlet to the carb and use a right angle to SS braided line to the fuel pump?
How do I know if a fitting is NPT or other? Are the flares 37 degrees or 45?
Now listing all the fittings in order that I have starting from the carb which is a rochester 2bbl.
Male .8615" od thread 20TPI to female 27TPI
male .396" od thread 27 TPI right angle to female .4465" id 20TPI flare fitting (when tightened normally before messing it up it was at about 7-8 o'clock)
1/2" 20TPI fitting over .3215 OD/.251ID SS flare line
1/2" 20TPI fitting over .3215 OD/.251ID SS flare line
Fuel Pump
Long story:
Had issues last year where when the gas tank indicated half full the boat would sputter and not want to run at full throttle. First checked that I actually had gas (I did) Changed the fuel filter and it worked better for maybe a bit longer until it did the exact same thing. Also noticed the fuel filter bracket was cracked so I pulled that off and welded it back together. we'll come back to that later. Did a bunch of troubleshooting with no results. Pickup tube was good, replaced the fuel lines encase they were soft and collapsing, checked the drainback ball valve thing, all looked good. decided to clean the carb over winter and messed up the fitting as I said above where i mangled the fittings. Guess what, get to half a tank an still doesn't work. Think ok well only thing left is the fuel pump maybe it's not flowing enough once it has to lift the gas higher. In the process of pulling lines to get a part number off the fuel pump i notice some odd coloration just above one of the flares. Sure as heck the SS line from the filter to the pump is cracked. vibration and hanging from the previous owner must have cracked it. It never leaked (always under suction) and was behind the fitting so it was never noticed but you'd get enough suction and it'd be letting air in. Anyway I got a steel line and bender and that kinked like a cheap hose. So I got some nickle copper line and hand bent it but the flare tool was kinda junk so the double flare leaked a bit and I have to re do that, I may try to flare another piece or just grab some more ss braid line. But yeah with the upper carb fitting leaking I pulled the hardline from the carb to the pump and noticed some corrosion on the SS line near the carb so I kind of want to replace that and it might have gotten banged up from my previous errors.
Where does one go to get new fittings, will the clocking be the same if i buy something similar or do i run the risk of being in the same situation even if I do find a 27tpi to 20tpi flare fitting 90?
Any issue with going with a SS braided AN and using something like this https://quadrajetparts.com/adapter-i...ing-p-368.html
Last edited by a moderator:
