At the end of last season, I replaced the PCV in my carb as it had sprung a hole. Of course, this gad me fiddle with the carb. Now at the start of this season, the engine floods easy, and seems to run rich. Thoughts?

 

Needle and seat, float went south, wrong pcv?

 

I would trust the PCV at this point. How would I go about verifying the Needle and seat (isn't there a pair on my 7rt?). What about the float? Are there diagnostics I can perform in-truck with out having to pull everything a part?

 

Okay, I feel silly now - the needle and seat make up a valve that controls flow into the bowl. There is only one of these.

Could my issue be as simple as adjusting the two idle screws can can I do this with it mounted to the truck?

 

I agree with Toby on this. I would add to leave your idle screws alone for now. The Float level has to be correct or else nothing else will work correctly in a carburetor. Check over the needle and seat assembly as there maybe some dirt/rust/debris holding the needle and seat open. Maybe try tapping on the float bowl with a large screw driver handle and see if that helps. Also you may have a float that is bad, letting fuel leak inside of it, "drowning" the float, so the needle and seat stays open, letting excess fuel into the float bowl, that raise the fuel level in the fuel "well" inside the carburetor. Once that happens the engine has an easier time sucking excess fuel from the carburetor, making it run rich. Pull a plug or two and see how black they are. I would try to give you more details, but my experience is limited to 4010's and 4160 Holleys. On those about every season, if I do not pull the needle and seat assemblies and clean them out with carb cleaner and a little compressed air, I will have the same issues you are having on yours. Finally last fall I got smart and just emptied the fuel of them, no problems so far then this spring. I hope that helps.

 

Thanks hooler! I hope someone can give me details on how to check the needle and seat assembly as I haven't done that ever before and hate taking the carb off the truck and getting all the linkage back together.

 

I s'pose you'll need to get a rebuild kit. It will have all the gaskets and internal bits you will need. The float will be extra.The kit will have a gauge to help you set the float level and some minimal instructions on how to do your carb. I usually get my kits from Carb Junkies. Good service and all. Get your digital camera out and take pics as you go. I always do when entering uncharted territory, like replacing the belt on my mower deck for the first time. Wish I would have taken pics then. There's usually a youtube video for most anything you can think of. Afraid I don't have any experience with those Holleys but I'm sure someone can help you out if needed. Lots of knowledge on this site. If you have a brass float you can check it by submerging it in a pan of hot water. If there are holes in it there will be bubbles from the air inside expanding. They might not be real big, but if you see any it needs to be replaced. Hope this helps.

 

I am looking at the exploded diagram for your 7RT. I would attach a copy but the CD set it came from is copy protected. It shouldn't be too bad. See if first you can find a new air horn to main body gasket. If I am reading my parts pdf correctly, if your carburetor part number is 7RT-9510-A, it's part should be #7RA9516. To find this gasket go to rearcounter.com, put in the part number, and you'll find many vendors with this part. Just to be sure run your carb number by them to double check it. (I like Green Sales myself.)
Make sure the engine is cold, Take off the air cleaner, disconnect and plug the fuel line, disconnect the choke and accelator linkages, next pull the 5 screws holding the air horn on, lift up the air horn very carefully, (try not to tear up the gasket, but it probably will tear) and you will see the float and needle and seat above it. Turn it upside down so you can see it all and inspect and clean them up well! Also clean up you fuel filter and filter bowl. Put it all back together. Hopefully you have the new gasket, attach the choke and accel linkages, and then un-plug and attach the fuel line. Start it up and check for leaks! If you don't feel comfortable doing this, you may just want to take the carb off and send it in for rebuilding. Before you ship it off, i would carefully count the number of turns to screw in the mixture screws, and write that information down! That way when you get it back, you could put those back to the original settings, (assuming they were in correct adjustment before.) I hope this is all correct. If not I know we have better more experienced hands that will weigh in on this...

 

I would mentally go over what you messed around with. If it was running fine before you fiddled with it, but now it's rich, I'd lean toward the cause being you.

However, floats do go bad, and it's not much work to clean a carb out so if you have some time, get in there and look around. Good luck!

 

Silly me I should of asked earlier. What did you fiddle with on the carb. Just the idle adjustment screws?

 

Are you talking about the power valve? PCV's aren't inside a carb. If you mean power valve, many are bad out of the box, many are too tall and won't let the throttle section seat on the main bowl.