F carburetor brass screws for throttle valve

[Vae Victus]

While trying to remove the brass screws on the throttle valve I snapped them both off. Turns out they are peened into place and the exposed threads are supposed to be ground off before removal.

For future reference, I found the part at McMaster Carr. If anyone has other sources, document here.

This is an F carb, 1973. I'm pretty sure it's the same for other years.

M3 x 5mm x 0.5 pitch

mcmaster.com part number:90928A300

@65swb45 looks like I found my source.

 

[thorslc1977]

May I ask why you were trying to remove screws? Is that the carb Mr. Algahzy rebuilt for you?

 

[ToyotaMatt]

 

[ToyotaMatt]

This is My Technicians Training manual from T-Ten College , it covers " Special Servicing "

getting that snapped screw out of the throttler shaft is going to require some " Extra Special Servicing "

 

[ToyotaMatt]

@S4Cruiser

 

[ToyotaMatt]

 

[Vae Victus]

Well ain't you special with your NLA carburetor manual! Send me that and I'll scan it and put it up on Marshall's "Cheap Manuals" thread!! Would have been very handy before trying to unscrew those damn things. I should have known that brass screws meant something!

Thanks for posting the pics!

 

[Vae Victus]

May I ask why you were trying to remove screws? Is that the carb Mr. Algahzy rebuilt for you?

Fair question. The throttle valves were sticking when rotated manually and I was trying to diagnose. The main throttle valve brass piece actually hung in the body and bent slightly, and I thought that was the problem, when in reality it was just a symptom.

Shortly after I snapped off both heads, I learned that this loose washer was the problem (see photo). The washer in question is shown in the original photo I took when I got the carb. It either migrated down from the back side of the retained connector where the arrow points, or it migrated up from where it was in the photo, but either way it was in the middle getting hung in the main throttle arm mechanism as it rotated. Somehow it got stuck enough to push the shaft holding the brass butterfly valve to the side just enough to force the butterfly valve into the side of the throttle body. It deformed (bent) it slightly when I tried to manually close the valve using the throttle arm.

I fixed by replacing with a slightly smaller washer. No big deal.

I talked to Mark and I don't think that washer is a part that he replaced, so not his fault.

 

[Vae Victus]

Though I disagree that it is possible to "unscrew the 2 high-speed butterfly mounting screws". Once they are deformed, they are not coming out. You don't have to twist very hard to discover that. You must grind them off first, then try to unscrew the remainder.

View attachment 1799343

Matt, is there a step 6 here regarding what to do with the brass screws once reinstalled?

 

[ToyotaMatt]

Though I disagree that it is possible to "unscrew the 2 high-speed butterfly mounting screws". Once they are deformed, they are not coming out. You don't have to twist very hard to discover that. You must grind them off first, then try to unscrew the remainder.


Matt, is there a step 6 here regarding what to do with the brass screws once reinstalled?

There staked on the shaft side with a punch at the factory so they dont come out .............easy


i might try applying some little butane crack torch type heat , and see if physics takes over

 

[thorslc1977]

Thanks for response--- Reread my post and I was concerned it sounded smart-ass. Not the intention at all. I am glad you did not take it that way. I was just confused. And also no dig on Mr. Algahzy either. I actually thought that was a different carb or you did that before you sent it off. I have driven my FJ40 for 41 years now. Looking forward to you having yours on the road. You certainly have put in the hard work to deserve it!

 

[Vae Victus]

Thanks for response--- Reread my post and I was concerned it sounded smart-ass. Not the intention at all. I am glad you did not take it that way. I was just confused. And also no dig on Mr. Algahzy either. I actually thought that was a different carb or you did that before you sent it off. I have driven my FJ40 for 41 years now. Looking forward to you having yours on the road. You certainly have put in the hard work to deserve it!

No, this is Mud. Folks are always nice, so I assume that when reading anything! I thought it was very funny, and valid.

Now if this was pirate4x4, I would have assumed otherwise, but I don't go there simply because of that.

And thanks, eager to get ONE vehicle on the road! And having fun doing body work and rebuilding the engine bay of the frame off at the same time.

 

[Vae Victus]

Update. Drilled the brass screws out and ran the tap in the holes to clean out the remainder (especially on the 2nd one that did not come out). The Dremel worked ok, but it really spun too fast for this job.

 

[DSRTRDR]

I got a M3 machine screw at Lowes - not brass, but it hasn't come out in some 10 years, either - it wasn't difficult to stake it despite the slightly harder material

 

[4Cruisers]

Do you have any more of these screws out of the package of 50 you ordered? I just need two of them. Willing to pay for a couple, plus shipping. Thanks.

 

[Badad]

While trying to remove the brass screws on the throttle valve I snapped them both off. Turns out they are peened into place and the exposed threads are supposed to be ground off before removal.

For future reference, I found the part at McMaster Carr. If anyone has other sources, document here.

This is an F carb, 1973. I'm pretty sure it's the same for other years.

M3 x 5mm x 0.5 pitch

mcmaster.com part number:90928A300

@65swb45 looks like I found my source.


View attachment 1799199View attachment 1799201

Do you know if these are the same as the choke plate screws?