artificialreef
Chief Petty Officer
- Joined
- Feb 21, 2009
- Messages
- 504
Hello folks, I have the dreaded mercruiser 470 1983. I am not getting fuel inside the carb so decided to do a rebuild. All the carb id info i can find says the rochester has 2 air fuel mixture screws on the base plate and the mercarb has 1. Heres where it gets messed up. I have the id tab connected to the carb that says its a mercarb but it has 2 mixture screws. Now i think its not to hard to believe that the po took a mercarb upper and attached it to a rochester base plate. Here are some more attributes that may help in the id.
1.it has the bent accelerator pump shaft like the rochester.
2.it has no choke piston like the mercarb.
3 the id tag says 13765990A1 (this doesnt mean the po didnt transfer it to another upper carb assembly)
4. like i mentioned above the base plate has 2 air mix screws.
I guess my questions are
1. Do people do this? attach a mercarb upper with a rochester base plate.
2. Will it work like that?
3.When i disassembled the pump assembly there was no return spring and check ball in there. Do some models not use them. (if i am putting it back the merc is diff from the rochester, which do i use)
4. The manual says to remove the power piston assembly you depress it then pull it out and it should just click out.
mine does not come out. Any tricks? Do i just muscle it out. I dont see where there are any lock springs, whats holding it in. There is a hole going toward it.
5. I guess depending on what model you folks determine this is i may also have to put the choke piston back in?
When i pulled off the fuel line to check for flow there was no filter and spring in the inlet like there is supposed to be also. I am afraid someone who didnt know what they were doing jacked with this (when it didnt work they just started taking parts out and ditching them,choke piston,check ball,diff base plate). It certainly doesnt go by the book. I never saw it run right.
Thank you in advance folks any help is appreciated.
1.it has the bent accelerator pump shaft like the rochester.
2.it has no choke piston like the mercarb.
3 the id tag says 13765990A1 (this doesnt mean the po didnt transfer it to another upper carb assembly)
4. like i mentioned above the base plate has 2 air mix screws.
I guess my questions are
1. Do people do this? attach a mercarb upper with a rochester base plate.
2. Will it work like that?
3.When i disassembled the pump assembly there was no return spring and check ball in there. Do some models not use them. (if i am putting it back the merc is diff from the rochester, which do i use)
4. The manual says to remove the power piston assembly you depress it then pull it out and it should just click out.
mine does not come out. Any tricks? Do i just muscle it out. I dont see where there are any lock springs, whats holding it in. There is a hole going toward it.
5. I guess depending on what model you folks determine this is i may also have to put the choke piston back in?
When i pulled off the fuel line to check for flow there was no filter and spring in the inlet like there is supposed to be also. I am afraid someone who didnt know what they were doing jacked with this (when it didnt work they just started taking parts out and ditching them,choke piston,check ball,diff base plate). It certainly doesnt go by the book. I never saw it run right.
Thank you in advance folks any help is appreciated.
