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2bbl Rochester rebuild

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mkpj1

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"I had posted about a hard sta

"I had posted about a hard starting hot 140 cruiser awhile back. Currently I am rebuilding the carb which is a Rochester 2GC. The checkball is snug and will not come out of the seat. Is that a problem?

Thanks,
Ken"
 
Let me clarify that the ball I

Let me clarify that the ball I'm talking about is the one in the pump well and not under the spring.
 
Where did you get your rebuild

Where did you get your rebuild kit from? Good instructions? I'm going to be doing the same thing in about a week as soon as I find out what Mercarb I have. One hkit has a metering rod(?) that's bent 90 and the other is straight.
 
"Gently tap it with a SHARP po

"Gently tap it with a SHARP pointed center punch and tack hammer diretly overhead just to the side of center. If it doesn't dislodge after a few taps, carefully drill a 1/16" hole into the ball deep enough to insert a small sheet metal screw w/bolt head and use a nut driver to insert the screw and keep turning while pressing down."
 
"Thanks for the info,

I got

"Thanks for the info,

I got mine at Napa. Make sure you have the serial number. terrible instructions in mine. Could not rebuild with it if I didn't already know a little. that's why the question on the small checkball. I probably should have tore it down prior to buying the kit. Mine has a lot of pitting, white oxidation in the float bowl, and this stuck ball.

My serial number cross checks to a 165 mercruiser but is still a 2GC. I should be safe going with the 140 float settings...right? Float info uses serial number for float listings and of course mine is not in the 140 list. Thoughts?

Ken"
 
"Per manual: Engine model 165

"Per manual: Engine model 165 with Rochester 2GC

Float level: 21/32" (16.7 mm); before checking float level, if needle is spring loaded, raise float and let it drop on its own; do not force it.

Float drop: 1-3/4" (44.5 mm) measured from air horn with gasket in place to bottom most part of float.

Pump rod: 15/16" (23.8 mm)

Choke setting: index marks aligned

Choke unloader: 5/64" (2.0 mm)

Preliminary idle mixture setting: 1-1/4 turn"
 
"Pitting and white oxidation c

"Pitting and white oxidation crud are sure signs that you have had water in the carb at some point. Do you have a water separating filter? If not, you should install one. Check your fuel tank for water on the bottom.
Have you tried a good degreaser/carb cleaner solvent? That should free up the check ball if you let it sit for a while. The passage below the check ball that supplies gas to the accel pump will likely be plugged off with the same crud, so make sure you blow out all passages well. Otherwise you will not be a happy camper.
Rod"
 
"I don't want to hijack th

"I don't want to hijack this thread but this is related: When a carb gets old or beaten up, I was warned that the rebuild kit does not provide all the parts that might need replacing. What do youlook for when taking a carb apart that shows it needs more than a what a kit provides?

ALSO - specs from the manual were quoted above. I could have sworn there was a post somewhere saying there were revised (read: improved) specs somewhere online that some learned person had put together."
 
"nick,

I think Troy posted

"nick,

I think Troy posted a Mercarb update a few weeks back that had updated specs in PDF format.

Guy, Let me clarify, I have a 2GC with a serial number that identifies it with a 165 Merc. But...It's on a 140 merc. Do I use the specs for the 165(that wouldn't make sense to me) or use the spec for the 140(183cid) that I would assume I use? Just would like some of your thoughts to double check if I am missing something.

Rod, I'm with you. Yes it does have a water separator but before I bought it I think it sat along time. I drained the tank prior but I did not pull the lines or the carb to clean it out. Looks like our fine 10% ethanol laden gas sat in the bowl,,Ahhhh! I'm going to soak it again and blow it out again.

Ken"
 
"oops, that would be a 181 cid

"oops, that would be a 181 cid engine. This is probably a remanufactured carb put on at a later date.

I'm going to set it for the 140 engine at

5/8th Level
1-3/4th Drop
1-5/32 rod

Think I'm crazy, chime in, Thanks Everyone!"
 
Make sure to check the throttl

Make sure to check the throttle plate shaft for wear in the bushings. If you have a significant amount of side play it will cause vacuum leaks and make the carb hard to adjust.

Jack
 
"Per manual: Engine model 140

"Per manual: Engine model 140 with Rochester 2GC

Float level: 21/32" (16.7 mm); Fuel inlet needle is spring loaded. Before checking float level, raise float and let it fall on its own weight; do not force float downward by hand.


Float drop: 1-3/4" (44.5 mm) measured from air horn with gasket in place to bottom most part of float.

Pump rod: 7/8" (22.2 mm)

Choke setting: index marks aligned

Choke unloader: 5/64" (2.0 mm)

Preliminary idle mixture setting: 1-1/4 turn"
 
"Ken;
It seems logical to set

"Ken;
It seems logical to set it for the 140 specs.
The only issue I can see might be the main jets will be for a 165, and might need to be changed for the 140. I am not sure if they are different.
Guy, does your info include any details about the main jet number needed for the 140, that Ken can check out?
Rod"
 
Rod:

Not for a Rochester

Rod:

Not for a Rochester 2GC. Only for a Mercarb 32mm. It calls for Main Jet of 0.057" (1.43mm)
 
"Well,

Here is the deal. A

"Well,

Here is the deal. After studying the Rochester service manual and trying the sharp punch idea. I think it's fragged. I haven't tried the drill bit idea yet as I will need a extension. I think it's been jammed and was the cause for my problem all along. This particular carb has the inlet chamber from the float bowl to the pump well. There was no screen over the little hole in the float bowl. 120psi air into this chamber does butkiss to the checkball as it is quite happy in it's new home. So the pump can't vent after she gets warm. I stop to rest after skiing and instead of venting back to the float bowl it just forces the fuel out to the throttle body flooding the intake and causing hard hot start? Sound right?

I will try the drill technique but I'm thinking that will be useless as the aluminum has been reemed.

I have a pretty good junk yard here. Think I could go get the lower carb housing off a car and mate em as long as they match up?"
 
Be careful with using automoti

Be careful with using automotive carb parts. You have to make sure the bowl is vented back into the intake and not into the engine compartment outside the flame arrestor. The lower part of the bowl should be good to go.
 
"If that's a 3.0 liter fou

"If that's a 3.0 liter four banger, the hard hot starting is caused by the carb sitting atop the exhaust manifold! This causes percolation of the fuel: light stuff evaporates away, and the heavy crud that's left oozes over and falls into the motor (where it's reluctant to burn). In addition, when you go to refire, the carb is near empty, which complicated things in itself.

Here's a good trick to try: After a long, hot run, let it idle for a minimum of five minutes (with the dog house pulled back a few inches if possible). That lets everything cool down and reduces percolation.

Jeff"
 
"Other than the different numb

"Other than the different number of mixture screws, aren't the Mercarb and 2 bbl.Rochester the SAME? I'm guessing here but they seem alike. I thought Rochester stopped making them so Merc just made a copy themselves.
Chris"
 
"Last update. I'm a persis

"Last update. I'm a persistant bastard so i continued to work on it although I had reserved myself to the fact that Guy is right and this dog has had his day. Heat, cold, suction compression, soaking, any many variations. My neighbor suggested drilling from behind and JB welding it? He doesn't like me does he? Well I could not break up the love affair!

I went to the junk yard to look at some auto 2GC's as me and the boys never have a bad day in the junk yard. the guy gave me an old rusty one and I took it home for research. The lower housing in the carbs are alot different from main jets to variations in Venturi diameter. Venting is much different as well. So you guys are right in this case too.

I'll be saving my pennies for a couple weeks and off the water, Bummer.

Thanks for all the help!

Ken"
 
"Well, I got my reman. carb to

"Well, I got my reman. carb today from sierra today and guess what.

It's a friggin spitting image of that carb I got off the car. Little JB weld here and a plug here, and it's the same friggin carb! The Veturi's are small just like the car's. The venturi's on my boats where roughly 1 7/32's but they were worn and pitted. They were not worn 2/16ths though? Maybe a 32nd! Is that okay? Anybdy know what the spec is supposed to be? Seems I wold lose top end and gain low end torque, No? Will it make a difference in a 4 banger?"
 
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