rochester 4bbl choke problem. I think

[JLowe59]

Just put on a replacement rochester 4 bbl remanufactured carb on my rebuilt 305 merc. Boat now runs great but wont start when hot unless I hold the choke open manually while trying to start, then she fires right up. When the motor is warm or hot is the choke supposed to be open? When the motor is running the choke is open (the vacum seems to be working, but as soon as the engine is turned off the vacum drops(of course) but the choke shuts. On my old carb the choke would remain open while the engine was hot or warm. Any thoughts would help. This is a rochester 4 barrel with automatic choke. I got the rebuilt carb from marinecarbs.com Once she is running she runs great. but trying to restart is a pain. Thanks<br />Jim

 

[Don S]

Re: rochester 4bbl choke problem. I think

Does your new carb have electric choke? Did your old one? <br />If using the choke stove on the manifold with the linkage to the choke, is the choke hooked up?<br />Any info on engine and year would also help.

 

[JLowe59]

Re: rochester 4bbl choke problem. I think

thanks Don, no it is not electric, it is an automatic vacum diaphram type. it sits on a rebuilt 2000 jasper 305, original was 1979 898 merc. the choke linkage appears to be linked up. the vacum pulls the lever in tight when it is running and the choke is open . Iam wondering if the diaphram might not be working properly ( should the lever stay pulled in to keep the choke open even after the engine stops?)<br />Thanks, Jim

 

[Bt Doctur]

Re: rochester 4bbl choke problem. I think

sounds like the "choke stove" is not there.the vac. pull off is just that,pulls the choke plate open about an 1/8th.choke stove opens it from there.

 

[Don S]

Re: rochester 4bbl choke problem. I think

With the 2000 engine, you are going to need a carb with an electric choke. That vacuum pull off you described, is NOT a choke.

 

[JLowe59]

Re: rochester 4bbl choke problem. I think

the amount of things I am learning from this site are great! First I must say that I am finding out things that you only learn when you buy a "special boat" ie $2500 for the boat and trailer. <br />But now that I have I am going to make it right. Thanks for the replys.<br />What I found out thanks to a link from the search tool is that I am supposed to link the choke to a thermostaic coil in the manifold. I have an edelbrock manifold and there is no such coil in the manifold. so I basically have no choke at this point. Don S just confirmed this for me.(thanks Don) So my next question is do I spend the money for an "electric conversion" or just hold the choke open with a sping. How hard is it to put an electronic choke on and are there any other modifications that will have to be made? Thanks again for all the help.

 

[Bondo]

Re: rochester 4bbl choke problem. I think

So my next question is do I spend the money for an "electric conversion"

Ayuh,........ That's What Ya Gotta Do............<br /><br />It's pretty straight forward,........

 

[JLowe59]

Re: rochester 4bbl choke problem. I think

Thanks Bondo, and everyone else that gave me direction. I am going to put the electric choke on this weekend. I will let you know how it turns out.<br />Thanks Again<br />Jim

 

[180shabah]

Re: rochester 4bbl choke problem. I think

Hey Don, now you got me curious, if the vacuum pull of is not part of the choke, then what is it's function???

 

[JLowe59]

Re: rochester 4bbl choke problem. I think

Okay the electric choke conversion did not go as smooth as planned. Apparently the PO had put on an edelbrock manifold and the rochester quad. The edelbrock did not take a thermostatic coil so thats why he just left the choke removed in the first place. The super choke conversion kit wont fit onto the edelbrock so I now have to get the rochester 4bbl with the electric choke attached to it. The folks at Marinecarburetor.com were nice enough to switch it for me for about $80 additional because I ran the engine and now it had to be rebuilt all over again. Man am I pissed. So here I am waiting for my new carb that I can put right on my engine and start having some fun. At least now I know what a damn choke is. BTW it would have really helped if I had posted a pic of the carb BEFORE I started this project. I am sure some of the pros on this board would have been able to clue me in right away! Next time I am going to remember a picture is worth a thousand words!!