rochester 2bb power piston prob

[allons]

Rebuilding a carb off of a 2.3 cobra.
Actually just cleaning it out, don't have the kit yet.
From the manual, make sure the power piston moves freely. This one is frozen. There is some rust at the base as it enters the top of the carb.
It appears that it should move because it is spring loaded. any thoughts on the subject?

Allons

 

[Bondo]

Re: rochester 2bb power piston prob

Ayuh,... Replace it...

 

[TiredoleBoy]

Re: rochester 2bb power piston prob

Yep clean the housing, the spring, the passage way, Be sure to blow out all holes with a pressured blow gun. ( water must have gotten in the carb for this to occur. Install a new power piston and see what happens. ( that is usually in all Napa kits, but some places it is separate) Be sure this is free to do its job prior to finishing off the rebuild.

 

[allons]

Re: rochester 2bb power piston prob

Thanks guys. Now all I have to do is get out without snapping it off.

 

[TiredoleBoy]

Re: rochester 2bb power piston prob

Thanks guys. Now all I have to do is get out without snapping it off.

Soak it in a solvent. Yes the entire carb. I think they still make buckets of solvent to purchase?

 

[allons]

Re: rochester 2bb power piston prob

Update on power piston prob. Soaked it, pulled on it, twisted it and wala the rod pulled out. The bottom end of the rod was broached, so something else was attached to the other end. Saw what was attached and will soak it again.
Tomorrows another day.
Allons

 

[Bt Doctur]

Re: rochester 2bb power piston prob

have tried just unscrewing it?
http://www.boatfix.com/merc/Techbk/94/94hg5b.pdf

 

[rodbolt]

Re: rochester 2bb power piston prob

are you talking about the brass piston that is threaded in the bottom of the fuel bowl or the actuating rod in the top cover?

 

[allons]

Re: rochester 2bb power piston prob

This part is listed as a power piston and is located on the top portion of the carb.
After 2 soakings I was able to get the brass piston out by using a screw just larger than the hole in the top of the piston and a few washers. Then screwed the screw in. Once the head of the screw hits the washers it acts like a hub puller.
So, success and on to the next fix in the fuel system.
Thanks everyone for the help. I'll surely be back.
Allons

 

[allons]

Re: rochester 2bb power piston prob

Back again:
rochester 2bbl __ Carb # 17086107
1987 Blue fin 2.3 Cobra
Power piston not offered in kit, don't make them anymore.
Do any of you think it would it be a good idea to try to make my old one new again. The only damage is to the rod that is attached to the brass piston.
I should be able to make a new one using the same dimentions.
Somebody please give me some good news.
Allons

 

[gump271]

Re: rochester 2bb power piston prob

Allons,

You may have already found what you needed, but here's what I've found.

I attached a photo for those who aren't sure what a power piston is, because there a very few parts diagrams that even list them.

I had the same issue, broken power piston, for a 1985 Mercarb. I found one by checking Mercruiser shops in my area, I live near Lake St. Clair in SE Michigan. Luckily, one of the places had a carburetor they used for parts and I was able to get a functioning power piston.

I found a site that sells power pistons for the 2G & 4G Rochester carbs. I don't know if these are compatible to your marine carb, but you could call them and ask. Below is the URL to there site.

http://www.hotrodcarbs.com/parts.php?Carburetor_Parts

If the one they sell isn't right, I would just check locally like I did.

Good luck,
Bill

 

[allons]

Re: rochester 2bb power piston prob

Thank you Bill;

Just to find a power piston for sale makes me happy.
I am going to order the rebuild kit as well as the power piston.

Allons