Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

rochester carb Metering Rods and Jets


bculli05's Avatar
Member

Join Date: Apr 2001
Posts: 82
MI

08-01-04, 10:10 AM   #1  
rochester carb Metering Rods and Jets

Hi All,
I have been having a big prblem with raw fuel in the water. After to talking to many people about this I replaced the float as I was told this is a common problem with older rodchesters. By the way its out of a volvo Penta 225E #17059298. So, I replaced the float had someone that knew what they were doing adjust to 3/16 putit back together and boom same problem no change. I started asking around again and I was told to check out my metering rods and jets. Also, I checked my fuel pressure and its a a constant 6 1/2 PSI which I was told is correct. Back to the rods and jets. I pulled it apart and noticed the with the power piston all the way down the metering rods still dont close off the jets completely. Its like thay dont go down all the way. Is this normal? After that, I pull th rods and jets out and physically slid them together. Are the rods suppose to easily slide right through the jets or are they suppose to completely shut the jets off? the jet number is 69 and teh rod set are stamped 40B. I also poured and portion of fuel into the bowl of the carb with the jets out to see if it was leaking straight through but it never seemed to leak out. The chamber where the jets screw into, do they only disburse fuel under pressure?
Thanks for any help

Brian

 
Sponsored Links
rickf1985's Avatar
Visiting Guest

Posts: n/a

09-04-04, 04:38 PM   #2  
rickf1985
Brian, The rods will not close the jet completely. They are designed to meter fuel according to throttle position. More throttle, thinner part of rod in jet. Has the carb been rebuilt? possible that the inlet valve is not shutting all the way. How much raw fuel are we talking? Can you smell gas? Rochesters are a good carb but they are rather complex. You could have a clogged air bleed or passage. If it has not been rebuilt you should have it done.
Rick

 
bculli05's Avatar
Member

Join Date: Apr 2001
Posts: 82
MI

09-07-04, 09:11 AM   #3  
Carb help

Hi Rick,
Yes the carb haas been rebuilt. I soaked everything that was removable for a few days to ensure everything was clean. You mentioned something about an inlet valve. Is that the needle and seat your talking about? I am for sure that the float is properly adjusted as I have had three professional carb guys double check it. Everyone that looks at this carb says it should eb ready to go. I put it back on run it for about a half hour and low an behold, it starts loading up and tons of fuel in the water. I barley made it back into the well last time. Now the air passage you speak of. Thats exactly what my theory is, It just seems like it not getting enough air. Where would I look for this air passage? I've even been told it could be the primary jets channels wher they drill them out at the factory and plug them could be leaking. I have epoxied over the plugs to ensure that wan't the problem. Dont worry, i used the proper epxoy for fuel. I am no carb guy, but it really seems like something minor and I'm just overlooking it.

 
rickf1985's Avatar
Visiting Guest

Posts: n/a

09-07-04, 02:22 PM   #4  
rickf1985
You say you soaked everything for a couple of days, what did you soak it in? Most carb cleaners are potent enough to do damage in a lot less time than that. Assuming that no damage was done ( If this was an over the counter cleaner then you are probably alright) What I would do is get a couple of cans of carb cleaner, 2+2 is my favorite, and start spraying down each small hole you can see from the top. If that does not work then the carb will have to come apart again. If this carb has been rebuilt you should not have clogged passagways although I have seen it happen. Send me your phone number at [email protected] and I will try to talk you through a couple of things. Tell me a good time to call also (what time zone?). You say this happens after about a half hour of running which means it runs good for a while? If you want to pull the carb you can check the screws that go up through the bottom, that will cause a vacuum leak which may cause the metering rods to go rich. Send me your number and I will call you, it is a lot easier to talk then type!
Rick

 
rinaldo180's Avatar
Visiting Guest

Posts: n/a

10-13-04, 08:26 AM   #5  
rinaldo180
Fuel laden float?

You might try checking you float for fuel saturation. I'm not sure about all Marine applications but I have experienced the "Heavy Float Phenomenon" myself in automotive carbs although most marine carbs I have rebuilt have brass floats. Even the brass floats can leak gas internally and create a problem.

 
Search this Thread