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RicardoJM
08-30-2010, 09:54 AM
The carb that came with my FJ40 is a November 1969 2 barrel. I recently sent the base out to Marks Offroad to have it drilled for ported vacuum. Last week I took it apart cleaned it up put it on my truck.

The carb is running the following jetting;

Primary Slow Jet - 50
Secondary Slow Jet - 50
Power Valve - 80
Primary Jet - 108
Secondary Jet - 180


This carb had the following issues that were identified during the rebuild.

The gasket and ball bearing were missing from the acceleration pump discharge hole. These parts come in the rebuild kit.

The Power Piston was missing the retaining clip and was stuck open. I was able to get a retaining clip from an old carb carcass. I used steel wool and elbow grease to dress the piston and piston hole. The piston is opereated by vacuum and the fit needs to be correct.

The following issues were identified after the rebuild when tuning.

At some point in the past the venturi had been put in the wrong barrels. During the rebuild I put them back where they had been pulled from. This resulted in hesitation and jerkiness when starting out in 1st gear. With the secondary venturi in the primary barrel, the engine was not getting the correct mixture. A closer inspection of the photos in the FSM and some web research led me to identifying the problem. Upon swapping the venturi to the correct barrels, the difference was amazing.

The accelerator pump arm was too short resulting in a significant flat spot at the start of acceleration. I swapped the linkage arm with one from an old carb carcass and the flat spot was gone.

While I now have ported vacuum unfortunately, the distributor in my truck is a vacuum retard:(. Of course, until I figure out why my engine is eating distributors - I won't be able to run a vacuum advance. Nonetheless, the truck runs great:D. I took it out yesterday, C-470 to Highway 72 to Peak to Peak to Highway 119 and did some fly fishing in S. Boulder Creek and Boulder Creek. It was a great day to be out and about with the top off.

SteveH
08-30-2010, 11:21 AM
RE: Retard distributor:

Just put a short hose with a filter on the 'retard' side of your distributor, and leave the advance side connected to ported vacuum. The filter will keep dust/water out, such as any would enter. I don't believe that a 'retard' distributor is bad unless you leave the 'retard' side connected.

RicardoJM
08-30-2010, 12:08 PM
RE: Retard distributor:

Just put a short hose with a filter on the 'retard' side of your distributor, and leave the advance side connected to ported vacuum. The filter will keep dust/water out, such as any would enter. I don't believe that a 'retard' distributor is bad unless you leave the 'retard' side connected.

My distributor has only one connection and it is covered to protect the innards. The 1978 small cap dizzy was either advance or retard - just my luck the one I have is retard. There used to be a kit to convert it over to advance, but the kit is no longer available.

SteveH
08-30-2010, 02:59 PM
Wow - I have a '77 engine in my '78, and I thought both distributors (since I did the swap) had a vac retard and advance. The things you learn. I know that the vac advance parts for those distributors are pretty much unobtanium.

Thanks for setting me straight.

Rzeppa
08-31-2010, 12:18 PM
http://rzeppa.org/tech/distthm.gif (http://rzeppa.org/tech/jimcdist.htm)

HTH

RicardoJM
08-31-2010, 01:17 PM
Wow - I have a '77 engine in my '78, and I thought both distributors (since I did the swap) had a vac retard and advance. The things you learn. I know that the vac advance parts for those distributors are pretty much unobtanium.

Thanks for setting me straight.

I'm not that sharp, this is the link (http://www.ih8mud.com/tech/dist.php) to distributor information from Mr. Chenworth.

MDH33
08-31-2010, 02:21 PM
Isn't TrollHole on MUD selling correct reproduction vacuum advance distributors? A lot cheaper than I've seen the OEM ones for too if I recall.

RicardoJM
08-31-2010, 03:40 PM
Isn't TrollHole on MUD selling correct reproduction vacuum advance distributors? A lot cheaper than I've seen the OEM ones for too if I recall.

Yes he was, but he may be overwhelmed with the carburetor sales. I just went out to his sub-forum on MUD and all I found were the carbs. BTW, these carburetors he is selling are a big hit. The current batch arrived last week and are all sold out.

Rzeppa
09-01-2010, 01:24 PM
I'm not that sharp, this is the link (http://www.ih8mud.com/tech/dist.php) to distributor information from Mr. Chenworth.

That is lifted DIRECTLY from MY (http://rzeppa.org/tech/jimcdist.htm) web site.

:rant: :rant: :rant: :rant:

This has been going on ever since 'mud came into existence. I had thought Woody had quit plagiarizing other people's stuff. He and I have had several conversations about this over the years.