Follow up to Rochester 2 BBL question

Has anyone with a Rochester 2 BBL, 225 V6 had a stalling problem when climbing? It seems better with me lowering the float, and also installing an adjustable fuel pressure regulator, but is still there. Any ideas would be appreciated. R.J.

 

Are you running stock or modified fuel tank? How is the pick-up tube mounted or do you drain from bottom of tank?

 

I have the stock, under the driver's seat tank, with the line under the tank.

 

I will check for vacuum leaks. It just floods out while climbing. I've heard that the fuel somehow gets from the carb bowl, and down to the throat. I will also try putting 2 smaller jets in it. I love the 225, and have had it in 3 Willys/CJ5s, and have never had this problem.

 

Do you have the internally or externally vented bowl?
I read some where ( maybe here, maybe in one of Moses Ludel's books ) that the internally vented bowl will cause that problem. Somebody else will correct me if I am wrong, I am sure.

 

Don't know about the Rochester specifically, but typically the bowl vents are inside the air horn. Ideally, if the float bowl overflows, the vents will overflow and dump raw gas down the throttle, killing the engine. Depends on the design of the carb though - Rochesters don't seem to have this problem though.

Smaller jets won't make any difference.

Did you check that the fuel delivery from the tank does not cut out on steep slopes?

 

It stalls out during a climb. I just messed with it tonight. It seems like I have to keep the fuel regulator at about 4 to 4.5 in order to start the engine, and run decent on an uphill street, but then it seems to flood going down hill. I put the float at 2 different levels also. I am ready to pull my hair out. I have 2 rochester carbs, both 2 bbl, and it does it with both. I got the 2nd carb because the first one was stalling on climbs, then I got the 2nd one. I rebuilt (not new jets) both carbs, and they both stall out.

 

Were the floats replaced at all? If they are the synthetic ones they can get saturated with fuel creating a running float level issue. If brass the seam can leak letting fuel into it creating a similar issue. Basically the float gets too heavy to hold the proper fuel level even though it may have been set properly during the rebuild. There is actually a float scale for checking the weight but it's pretty cheap to replace them. I'm not sure if one is available for your carb but a spring loaded needle and seat can be a big help as well.

 

I used to have a problem with my 2G on steep climbs (45 degrees and higher) thing flooded out and had to hold it wide open to start. Finally figured out that fuel was running out the bowl vent straight into the carb throat.
I used a short piece of 1/4" brake hardline gently tapped into the vent hole to extend the vent up almost to the top of the air cleaner. I also crimped this almost closed but left it open enough to breath a little and do it's job of venting. My flooding problem on hills went away, but then I started to dump oil out of the oil bath filter onto the firewall when the hills got really steep.R)
At that time I had a stock metal underseat tank pulling fuel from the bottom fitting and a cheap clicker style electric fuel pump with no regulator. Now I have a poly tank pulling from the top and the same cheap pump feeding the carb.

 

I haven't had any trouble with mine after a total rebuild & float replacement with a quality kit and making all adjustments per the spec sheet. I've been very impressed with the stock carb and stock 225. It's a bit rough during warm up, but after that, I have no complaints. I'm running the stock mechanical fuel pump. If I hit a big bump on a hill (like climbing over a rock), then it might flood or stall (which is typical for carbs).

Keep playing with it, and you should find the right combination of settings.

 

Well, I changed out the float, from a plastic one to the metal one, reset it to the specs, opened the idle mixture screws a little, set the fuel regulator to 4.5, and it is running great, at least on the streets. I have many hills around here, and it just flew up, and then didn't stall once on the down hill. I will take it out this weekend up to a place above Boulder Colorado and see how it does. Wish me luck. Thanks for all of the ideas. It really helped. R.J.

 

mine did that with 5# of fuel pressure. what happens is that the fuel pressure forces the needle open and dumps gas out the vent, flooding the motor. Stock pressure is 2.5psi, I run 3psi on the street and 2 offroad (adjustable regulator).

 

It seems like when I adjust the fuel regulator to less than 4.5, it starves the carb, and there is no power, and it often won't start or idle. When I put it back up to 4.5, it seems to run great.

Does anyone know exactly where the vents would be in the 2G? I assume that they are in bowl side, near where the brass fitting is on the outside of the carb. Any help?

Thanks. R.J.

 

I think the problem is solved. Thanks to everyone for the input. I put about a 4 inch piece of 1/4 inch hard brakeline onto the top of the air horn where the float bowl is vented, and bent it up into the bottom of the air filter. Then I put JB Weld into the rest of the hole so there were no leaks. I set my fuel pressure regulator at 4 1/2, because it just stalls out at less than that on the road. I did not re-adjust it for off road, but I might next time.

I took the Willys out last weekend, and it ran great. On one long uphill part of highway, at about 12000 foot elevation, it started sputtering, and I think that was just an air mixture problem, so I will open my two idler settings a little more. I climbed some very big hills, one about a 35 degree, for about a 1/2 mile or so, up at around 12,500 foot elevation, and it was doing great. I did stall out, I think because of the idle mixture, and I wasn't giving it enough gas.

I am so happy that the biggest part of the problem is fixed.