The Stovebolt Site Forums The Shop Area Engine Shop Carb. Rebuilding

I have a 66 Chevy LB/FS 292 w/4spd man. trans. It has the Rochester B 1bl carb.

I've got the carb. almost completely disassembled. There's only one thing I think I may need to remove before bathing it. Note the two tall tubes in the inside of the carb.
[img]http://members.truevine.net/[email protected]/66chevy/PowerPiston1.jpg[/img]
The one that's closed (A), the 'Power Piston', seems to be stuck. Actually, am I supposed to take this out during cleaning? More importantly, is it supposed to move (slide) during normal operation? Being as it has a spring under it, I would guess it is supposed to move. Here's the drawing that came with the carb. kit.
[img]http://members.truevine.net/[email protected]/66chevy/PowerPiston2.jpg[/img]

Any suggestions would be greatly appreciated. Thanks in advance.

Rance

First of all you gotta throw away the directions
sorry I am not much of a help on the carbs,

A is the power piston and should be removed, when you put it back together be sure the piston moves freely in the bore a sticking power valve is a common ailment with lots of carburators. The other tube im pretty sure is a vent,or possibly a siphon tube blow through it and see if it is open if it is theres probably no need to remove it. Ronnie

Ronnie is right.You need to remove piston A & clean it so it works freely. You probably can remove it with needle nose plyers or soak it awhile first. After you assemble #11 make shure the power piston does not hang up in the hole where it contacts # 16. They can get bent. It is not nessesary to pull tube B or dissasemble 14-15-16 if it is working ok. Hey I like the direction sheet Joker.

if you do need to remove 14-16, watch out for the spring and little steel ball that will fly across the room. i believe the kit has replacements for both, but i like to reuse the original stuff if it's still serviceable cause i know it fits!
tony

Well, doused it w/some oil, then I put some plastic around the base of the piston and tried to twist it, no go. The plastic kept slipping. I then took a pair of pliers and held it directly and gently twisted it and WALLA (or is that viola) it broke loose and I was able to remove it. Just a little sludge in there. I cleaned it up and it slides easily now. I was surprised to find that it uses no grommets. Oh well, as long as it works. Next step is to commence with the carb. cleaner and re-assembly. That should go much easier.

Thanks all for you help and feedback.

Rance

Rance keep us posted to your progress.

I proceeded to bathe the parts yesterday eve. Being as cheap as I am, I bought one can of spray carb. cleaner rather than the dip kit. I put one part in a baggie and put that one in another bigger baggie and then wrapped that in some bubble wrap so as to almost shrink-wrap the whole thing and slid that into a coffee can. I then sprayed the cleaner in there until the level came above the top of the part then zipped up the inner baggie. I let this sit for 30min, occassionally tumbling it for good coverage. I used this method for the three biggest parts of the carb. This worked well in conserving the cleaner. After blowing out the cleaner, I washed the parts with gas to make sure all the cleaner was out. Prob. overkill but knew it wouldn't hurt. Ready for reassembly tonight.

It may be a few days until I get my tank drained so as I reassemble I plan on squirting a little Mystry Oil in the key movable parts (power piston, etc.) to keep them free until I get fuel to them. Is this or another method recommended or is it rediculous? Comments welcome and TIA.

Also, when I reassemble, should I do anything to the gaskets such as apply a light coat of oil before installing them? I know I don't want to use any silicone on them.

Rance

Sounds like a good plan to me. I,ve never put anything on the gaskets but a little oil won,t hurt. Be shure to soak the acel. pump in oil if it is leather. If it is teflon or neoprene just coat it with oil.

Hey Rance,
Do you know what the part # is for your carb? I have the same set up but mine is in a c-60 flatbed. I can't keep it from overheating. Thanks, Jeff

Jeff,

I've only had my 66 (my first stovebolt) a couple of months. I took MANY pictures and have shots of it from EVERY angle during my rebuild. They came in handy for reassembly. I have a 1 barrel Rochester, probably like yours. I seem to see that lots of others want change them out for more power/reliability but I plan on staying with what I have. My part # is a Rochester 'B' 1 barrel.

As to the overheating, I couldn't imagine a carb. causing the problem unless running lean could cause it. I have a mixture adjustment for idle but not for power. I believe that is handled by changing jets. At sea level I'd stay with stock and only go to something else at altitude. A WILD guess would be that your jets may have been replaced for altitude (leaner) but you are now back down to sea level. I MAY BE WAY OFF BASE HERE so maybe someone else could correct me if I'm wrong.

Rance

Well, I got the carb. all put back together, lubricated in all the appropriate places. Bolted it back down, and hooked up all the linkages. I then proceeded to siphon the gas from the filler neck. Hummmmmmmm gas seems not too bad to me. :confused: Cancel this. I then put a section of fuel line after the fuel pump but BEFORE the fuel filter and into a clear container. I then turned the engine over (a few containers full) until it began to become much clearer. It was to the point that I didn't mind hooking it back up.

During carb. reassembly I had adjusted the idle and other screws on the carburetor to their previous settings. After applying the manual choke and giving it a few pumps on the gas while turning it over, it sprang back to life.

With that, I just HAD to take my sweetheart out for a spin around the block. She (my lovely wife) was REALLY reluctant to sit on the yet uncleaned seat cover. I have to agree, it does look like it's been more than a few years since it's seen its cleaner days, mostly just dust though. We were successful in making the block without incident. With the bellhousing cover still off, along with the hump cover removed, I did not feel like taking it further, just yet.

Once back in the driveway I could smell the remnants of oil (or something) that came from the engine compartment. From all the oil and residue on the engine, I'm guessing that was what I was smelling. I'll still have to investigate that though.

Next comes cleaning er up and getting er presentable (the truck, that is) for the 5mi drive into town. That ought to stretch the envelope enough. Thanks again to all of the good advice you all have provided. Till later...

Rance

Good job Rance, glad to hear she's back on the road. How does the clutch feel now that you've driven it a little?

Steve

Congratulations on your first carb rebuild! I did my first one about 1959 or so, at age 13. Carburetor cleaner does only one thing, it softens the gunk that accumulates in carburetor passqges, so you can blow it out with lots of compressed air. Immersion-type cleaner is the only way to go for professional-quality results when rebuilding a carb. Soak the disassembled parts in the dip cleaner for a couple of hours, or more if possible,then rinse with VERY hot water, and use a needle-sharp blow nozzle on an air hose to blow 55 gallons of air through every passage in the carburetor. (That's an estimate, more certainly won't hurt!) Bottom line- - - -use LOTS of air! If you just soak and reassemble, the crud just accumulates in a different place, further down the passage. Make all the adjustments specified for your particular engine as you reassemble, and adjust the idle mixture and idle speed to spec. after the engine warms up. Simple!
Jerry

Yeah Hotrod, I'll fine tune the mix and idle when I get more comfortable. May have ndn watch over my shoulder for that one though.

ndn, The clutch feels fine. It's the transmission that has me a little concerned. See the post "Identify this part please". The trans. sounds a little dry when driving (sometimes).

One of the next orders of business will be to make sure that all fluids (oil, trans, pumpkin) are replaced and all zirks are attended to. I'll start an appropriate thread for that, this one's complete.

Rance