Another Carb Rebuild Thread

[77mustard40]

Before getting to the issue my thanks go out to PinHead and others that contribute mightily to this forum. PinHead's Youtube Carb Rebuild videos gave me the courage to drop in.

I have a 77 FJ40 that I have owned since the mid 80's that I purchased with a Holley. About 10 years ago I swapped out for a Weber 38. Since finding MUD last year I have been working towards converting back to stock. I have purchased a 76 carb (so I was told), air cleaner assembly, pedal and linkage.

This evening I set off into dissassembling the carb. Here are a few pics.

 

[77mustard40]

and here are a few more pics of progress

 

[77mustard40]

The air horn disassembly came off without a hitch. I was on my way into the base when I got to the jets. The primary came out nice and clean, but the secondary appears to be the victim of abandonment in a previous rebuild.

I have tried to get a picture or two but its tough in the bottom of the bowl. The face of the secondary jet is totally stripped so I have hit it with PB and now I'm looking for help. I really don't want to get out an extractor as I have mostly poor experiences. Does anyone have the silver bullet?

 

[edwjmcgrath]

IIRC you're going to want the biggest/widest screwdriver blade that will still fit through the access hole. Be careful not to make it worse than it already is. Take the primary jet to to a couple of stores and pick up a couple of different screwdrivers that fit tightly. If a screwdriver that fits tightly doesn't fit through the access hole, try grinding down the width of the screwdriver a bit. It should not be that difficult to remove.

In the end, if you can't get it out, there is no rule that says that you must remove every part during a rebuild. If the secondary is clean and working, you can try just leaving it in.

 

[77mustard40]

IIRC you're going to want the biggest/widest screwdriver blade that will still fit through the access hole. Be careful not to make it worse than it already is. Take the primary jet to to a couple of stores and pick up a couple of different screwdrivers that fit tightly. If a screwdriver that fits tightly doesn't fit through the access hole, try grinding down the width of the screwdriver a bit. It should not be that difficult to remove.

Thanks for the advice edw, nothing like tool shopping!

I've kept going knowing I want to get that secondary jet out before dipping and cleaning. More pics of progress.

 

[77mustard40]

...and finally at the stopping point for the night, I've got it disassembled (with the exception of the secondary jet) and ready to clean.

Tomorrow I will stop for some carb dip and spray cleaner, and look for a fat screwdriver. Also saw on another thread where a Mudder tapped a small torx head into the hole of the jet and got it to turn so I may grab one as well as a second approach.

Who has the most comprehensive rebuild kit?

 

[edwjmcgrath]

I got mine at NAPA but was disappointed that it did not include the secondary diaphragm. They sell that as a separate item.

On screwdrivers, what about that big fat one with the yellow handle that you are using? I'd take a grinding wheel to the sides of that until it fits through the access hole.

 

[skidplate]

If you haven't tried yet, spray around jet with PB Baster. I had the exact problem with mine. It was the first time I've used the Blaster. 20 min. later it unscrewed like butter. My .02

 

[Pighead]

Who has the most comprehensive rebuild kit?

I don't know if Toyota still has a rebuild kit, but I got one (years ago) and it was nice.
Keyster sells the kit I usually see these days, comes in an orange box and has a one-page directions sheet and exploded view. Many of the 'Mud vendors sell this kit, Kurt comes to mind first, sometimes you can find this kit at a good Napa too.
Vacuum diaphragm for the secondary is usually sold separately. New jets used to be available from Toyota individually, I haven't checked lately.

 

[weagle99]

If you haven't tried yet, spray around jet with PB Baster. I had the exact problem with mine. It was the first time I've used the Blaster. 20 min. later it unscrewed like butter. My .02

I am convinced that it is impossible to work on a 40 without large quantities of PB Blaster.

 

[77mustard40]

I am convinced that it is impossible to work on a 40 without large quantities of PB Blaster.

Loaded it up with PB before shutting it down in the garage, we will see what tomorrow evening brings. Thanks for the input guys.

 

[Pin_Head]

Leave the jet if it is stuck, but check it to make sure it is not obstructed.

 

[edwjmcgrath]

If you decide to remove the damaged secondary with a torx (which sounds like a reasonable idea)...my experience is that the small headed ones come at the end of a shaft that has way too much torque (no pun intended). You're going to want something stiff. You might try picking up a small torx head that will fit on a 1/4" drive. That way the shaft won't flex when you turn it.

 

[subzali]

You know how to check the date code on a carb right? You can figure out the day (literally) it was made that way.

What are you planning on doing with the power valve vacuum port? On a '77, I believe the power valve is controlled by internal vacuum passages. On the '76, it's controlled by external vacuum, so you'll, probably want to hook it up like a '76. Is your rig going to have emissions equipment?

The Hygrade kits seen on ebay and elsewhere online are also considered to be good kits.

 

[bsevans]

I would buy a screwdriver that has horizontal teeth that keep it from slipping. When we serviced military helicopters the screws that held the panels on were often buggered up. I know this may sound strange but the idea was widely used to turn a panel screw. Wet the screwdriver bit and push it into a box of Ajax powder. The powder has grit and tends to fill the slot allowing more torque on the screw. I've seen it work on stubborn screws hundreds of times.
As far as the best rebuild kit, this is no contest. The most complete kit available is the Keyster Kit K11-374A which includes All gaskets; accelerator pump; float needle; main jets and slow jets and power jet; air screw and idle screw; misc packing and gaskets and boot.
It is available from www.siriusconinc.com for $22.50

 

[77mustard40]

You know how to check the date code on a carb right? You can figure out the day (literally) it was made that way.

What are you planning on doing with the power valve vacuum port? On a '77, I believe the power valve is controlled by internal vacuum passages. On the '76, it's controlled by external vacuum, so you'll, probably want to hook it up like a '76. Is your rig going to have emissions equipment?

I am really new to carbs so I actually don't know how to find the carb production date. Once I get it cleaned up if it's not obvious I will search the threads to find it.

I haven't even considered the vacuum issues you mention, I have been just crossing one bridge at a time. My rig has all the emissions removed and based on the FSM, as I disassembled the carb it appears to be non-USA. The Rookie was actually encouraged by this thinking there would be less to deal with when I go into installation mode.

 

[subzali]

On top of the air horn there is a stamped number. You can post it up here or search in some other threads to decode it. It's simple. Year, Month, Day.

 

[77mustard40]

On top of the air horn there is a stamped number. You can post it up here or search in some other threads to decode it. It's simple. Year, Month, Day.

Sure appreciate the info, will check it tonight to make sure I order the correct kit.

 

[duffontap]

When we serviced military helicopters the screws that held the panels on were often buggered up. I know this may sound strange but the idea was widely used to turn a panel screw. Wet the screwdriver bit and push it into a box of Ajax powder. The powder has grit and tends to fill the slot allowing more torque on the screw. I've seen it work on stubborn screws hundreds of times.

Nice tip! I will try that.

I also had a very difficult time removing one of the jets. PB helped. You can also dip the carb and then try to remove the jet, and then dip again.

 

[77mustard40]

Thanks bsevans and buffon, I really like the Ajax idea as it seems logical. I think I will give that a try and if I can't get it then oh well I'll leave it in as PinHead suggests. I'll hit it with spray cleaner and the compressor after dipping to make sure it's clear of debris.