Carb guru's.... need some help with a stuck check ball (pics)

[fabrimacator21]

Okay so I've been having some problems with my 1978 305 omc (see this thread http://forums.iboats.com/showthread.php?t=354610) so I pulled the carb off and decided to overhaul it. I found a check ball where the throttle return spring/plunger goes and I'm not sure what exactly it does or if it should even come out. It seems to be stuck.

Heres the pics.

Carb is a rochester (not sure on the cfm)

If it should come out (overhaul kit came with a new one) how can I get it out? I've thought about baking the carb body at about 200 degrees to get the carb body to expand enough for it to let the ball go. Any Ideas?

 

[a70eliminator]

Re: Carb guru's.... need some help with a stuck check ball (pics)

That's the check ball for your accelerator pump, usually just leave it alone but if it's stuck you need to address it, there is a spec on the gap between the ball and the bridge the holds it in place the carb kit may contain that info and a new check ball, all i know is that little check ball should be free to bounce around between the bridge and the seat.
Ok hold on, I just looked at the photo again and that may not be the accelerator pump check, I shouldn't have replied I'm not too familiar with that carb I'm just guessing so take it for what it's worth.... = nothing.

 

[ErieRon]

Re: Carb guru's.... need some help with a stuck check ball (pics)

That carb looks like a Rochester 2G. Here's a link to some original service info.;

http://www.oldcarmanualproject.com/manuals/Carbs/Rochester/2-Jet/Manual/MCarbRoch1973__2G.htm

If it is a 2G, I think that check ball is aluminum and you do need it, and it does need to be free. Mine is a 1984 (2GC) and has a newer style accelerator pump that does not use it, but it always comes in the kit.

Maybe you could soak it in some PB blaster and then blow back through one of the venturis to free the ball. The outlet from that well where the check ball is goes somewhere? Just a thought. Good luck.

 

[Don S]

Re: Carb guru's.... need some help with a stuck check ball (pics)

That is the check ball that allows fuel into the accelerator pump cavity. If you blow compressed air into the hole marked with a red arrow below, it should shoot the check ball out of there, so cover it with a rag.
You also have to remove the T retainer, spring and second check ball (Circled in yellow) to make sure it's not stuck and the passages are clean.
After it's apart, soak in carb cleaner to remove the varnish that is causing the ball to stick.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Ok.... I'll go grab some PB blaster. I have already tried blowing compressed air in that passage way but I was using carb cleaner. I'll try soaking it in the PB then hit it again with the air. If that doesn't work would baking it be a bad idea? I do that with RC engines to get the bearings out and it works great. Press fit or stuck, they just fall out. I noticed that the manual says temps can reach 200 degrees in the carb so I'm assuming 200 degrees would be as hot as I'd want to get it.

I replaced the T retainer, spring, and check ball right before I took the pic... the old spring was a little tweaked but the ball wasn't stuck. I was just trying to work around that stuck ball.

Thanks for the link ErieRon.

 

[ErieRon]

Re: Carb guru's.... need some help with a stuck check ball (pics)

I don't think heating the carb up slowly and evenly will hurt anything, and it might free the ball. Some shops boil carbs in a cleaning solution to clean them and I'm guessing that has to be over 212 degrees F. Just make sure you remove everything that you have reinstalled.

Good luck.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Okay... I've tried soaking it in Pb blaster for 3 hours and it wouldn't budge with the compressed air... also tried baking it at 200 degrees for 15 minutes then slammed it on a 2x4 and it didn't budge... I'm not sure what to do now. I'm thinking about drilling the ball out and picking the rest out.

On another note... could this cause the motor to fire up (hard to start... alot of cranking) and idle for a bit then die?

 

[fishrdan]

Re: Carb guru's.... need some help with a stuck check ball (pics)

That check ball allows fuel into the accelerator pump, if it's stuck you won't get a shot of fuel when you pump the shifter before starting, so I think this is part of the problem you are experiencing.

For getting it out, how about this. Apply air pressure (100#+) to the port DonS suggested, while lightly tapping on the carb body with a small hammer. The vibration along with the air pressure trying to push it out, could dislodge it. (Oh yeah, you are going to need a rubber tipped air gun to seal up port so the air pressure doesn't bleed off)

I wouldn't drill it as you could mess up the ball's seat.

 

[ErieRon]

Re: Carb guru's.... need some help with a stuck check ball (pics)

I agree with fishrdan...I wouldn't drill it unless you have an old style precision hand drill with a very small diameter bit. Even then, I would be worried about damaging the seat. On the other hand, just that small amount of torque might just pop it free.

Maybe you could use a pin punch and tap it at an angle on its diameter to try and rotate it loose ??? Pretty delicate work, but it might work.

Or;

I work with high pressures in my business. If you have access to a regulated bottle of inert gas (argon, nitrogen) there is a lot more pressure available there, than there is in "shop air" that you would get from a compressor. Most bottles of compressed gas have regulators in the 250-500 psi range. I can't imagine that with the right amount of pressure, and tapping it like fishrdan suggested, that it wouldn't pop out.

You would be creating a dangerous situation when the ball frees, so be very careful if you try it.

 

[ErieRon]

Re: Carb guru's.... need some help with a stuck check ball (pics)

PS; Looks like you're not alone. Check out this thread;

http://forums.iboats.com/showthread.php?t=357978

Seems extreme, but......................

Good luck.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Hmmm.... I did tap on it while I had the air to it (using a tapered rubber tip) and got nothing. I'm not sure where I could get access to bottled air. My buddy has a welding shop but I don't think he has anyway to hook up a nozzle to it.

I'm gonna stop by ace hardware and see if they have a bit thats long enough to reach it. All I'd need is a little divot in the ball... then I'm thinking I could drive a small flathead into that divot since it's aluminum, and try to twist it to break it free.

I'll let you guys know what happens.

 

[fishrdan]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Here's another thought, hydraulic that stuck ball out. Grab your whittling knife and carefully carve a wood dowel down to the exact size of the port in DonS's pic (red arrow), actually make it fit a bit snug. Fill the port and passage with oil/grease, insert the dowel and smack it with a hammer, ball should pop out.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Here's another thought, hydraulic that stuck ball out. Grab your whittling knife and carefully carve a wood dowel down to the exact size of the port in DonS's pic (red arrow), actually make it fit a bit snug. Fill the port and passage with oil/grease, insert the dowel and smack it with a hammer, ball should pop out.

I like that Idea.... Gonna be a PITA to get the dowel to fit but it sounds like it might work.

Drilling the ball isn't an option... can't find a bit long enough to get down there and one slip up could cause damage. I'm on my way to my buddies welding shop... after that I'll try the dowel.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Got it out! Thanks for the help guys.

Picked at it with a scribe while using a higher psi compressor.

My only question now is how do I keep the new ball from getting stuck?

 

[jtybt]

Re: Carb guru's.... need some help with a stuck check ball (pics)

My thought is the check ball was stuck because of corrosion/water sitting in the float bowl. Is there any sign of oxidation(white surface) in the seat area.

You could have a problem if fuel leaks back into the float bowl instead of squirting down the carb. It'll act like a ruptured, torn or loose accelerator pump cup. You may need a new carb body depending on how bad the seat is sealing.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

I looked at the seat and it seemed ok... soaked it in carb cleaner for 1/2 hour. I installed the new check ball and put the pump return spring and and pushed it down with my finger and now the new check ball is stuck... the manual says it should fall out when the carb is flipped over but it doesn't.

Is this normal?

 

[fuzzybob]

Re: Carb guru's.... need some help with a stuck check ball (pics)

No it's not normal. The seat has become enlarged probably due to corrosion. Like Charlie said: it's probably time for a new carb body.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Ok... I want to get it back on the manifold and see if the problem is fixed or not before I buy a new body... Hell I'll probably just go 4bbl if thats the case.

BUT, I just broke one of my idle screws. I screwed it all the way in (like a dumbass) to get a reference point of how many turns out from closed it was so when I go to put it back in I know how many turns to set it at.

It broke the tip of it off and I have NO idea where to find one. I'll check out NAPA tomorrow.

 

[jtybt]

Re: Carb guru's.... need some help with a stuck check ball (pics)

Until you broke the tip off of the idle air screws, I would have suggested using a lapping compound on 'Q'-tips to clean the surface where the check-ball seats.

Now, I think you have no choice but to replace the carb body.

 

[fabrimacator21]

Re: Carb guru's.... need some help with a stuck check ball (pics)

I'm not even sure where to go about getting one....

Any idea where I could get an idle screw? Napa doesn't have em and I can't find them on the internet.