reviving a 74' Scout II and I'm Green!

[ScoutTech]

Yeah the vacuum is still low. I will adjust the carb down and hopefully stop the backfire.

I suspect a leak some where as well. I just hope it's not the intake manifold since its such a pain in the ***** to change haha.

I will try the spray around the carb and manifold and check my vacuum lines again.

I will say I notice only a momentary drop in Rpms when pressing the brake, which I assume to be normal.

My pcv valve on the valley cover is not secure and pulls right out with almost no effort. I disconnect that pcv valve and I'm testing my manifold vacuum from there. I did notice a lot of pressure (air/smoke) coming out of the valley cover pcv though. Is that normal? There is no pressure coming from the valve cover pcv to air cleaner. At least nothing noticeable.

Hey man thanks for your help I've learn so much about my scout with your help and teaching.

-Josh

[ScoutTech]

Ok so my timing is at 10 degrees, idle is 780 rpms (700-880 constantly varying), manifold vacuum is 16 hg, dwell is 30, and she runs like crap!

the idle runs smooth for a second at 800 then dives and sounds like its struggling to get back up. Then runs smooth again and rockets up near 900. All, this with continuing back fire and sputtering exhaust. Throttle response is spot on tho.

I took off each plug wire to see if I could isolate one cylinder. It changed nothing. It ran just the same every time I removed a wire you could tell it was a cylinder down but continued to backfire or miss and rpms all up and down.

I'm only a few weeks away from having this scout road worthy If I could just get this engine running Smooth. I'm getting close to just giving up

[scoutboy74]

The only number that isn't up to snuff is your vacuum at idle...it's low. The question is, while being low is it steady, or does it bounce and flutter around in unison with the engine speed? It may sound like I'm repeating myself, and perhaps I am. There really are only two main causes for the low reading. Either there is a vacuum leak somewhere, the carb is significantly out of tune, or there is some sort of internal blockage within the carb...or a combination of any/all the above. My overall feeling on this based on the symptoms and everything else, is that your primary fault lies within some component of the fuel system. I'm not one to advocate throwing expensive parts at a problem as a means of solving it, but I sure would be curious to see how much differently your engine would behave if there was a brand new Holley 0-7448 in place of the current carb. I'm thinking the difference would be night and day. Your Auto/MC 2100 carb has been a question mark in my mind since day one of this process. It was a donation from some non/Scout vehicle. I know other Binder owners have reported success with that particular carb, but I've never had the occasion to play with one myself, so I'm not familiar with their intricacies. You're kind of running out of options. The vacuum should be higher, without needing to bump the timing to get there. If you can't achieve it via adjustments to the carb and ensuring there are no vacuum leaks, all your left with is a full blown carb rebuild or replacement. I know funds are tight for most folks. Be that as it may, in your case, if it comes down to that choice, I think you'd be far better off in the long run to replace it with something that has been proven time and again to work very well on these engines. I'm sure that isn't the answer you're looking for, but there comes a time where continuing to monkey around with worn out components in an effort to save money is false economy.

[ScoutTech]

So would it be a waste of time to pull a used factory carb and clean/rebuild it.

I havent installed my the auto lite plugs yet and after reading some more I'm thinking of exchanging them for the ngk. Which ngk plugs do you use?

Plans for the weekend. Replace oil pan gasket, oil, filter, trans filter, trans gasket, trans fluid, dif cover gaskets, dif fluid. Clean dif covers. I installed all the rear brake hardware and shoes, front calipers and pads, brake lines, master cylinder and booster. Now i have to bleed everything. Also running bars leak in the radiator and flushing out the cooling system. Hopefully install NGK plugs and confirm all of my ignition connections. Then fire it up, hope for the best and search again for Vac leaks.

Between the part stores and UPS I have a lot of boxes/containers in my kitchen.

- Josh

[scoutboy74]

Originally Posted by ScoutTech

So would it be a waste of time to pull a used factory carb and clean/rebuild it. - Josh

Yes, total waste.

NGK 3332

Quite an ambitious weekend planned. If you get as far as removing the trans fluid pan, you should also check/adjust the band tension. The rear band adjustment screw can only be accessed while the pan is off, while the front band screw is accessible from the outside of the trans. The job requires a 5/16th inch, 8-point socket and a torque wrench capable of a 6 ft/lb setting, which is equivalent to 72 in/lbs as specified in the manual. The shorter the torque wrench, the better. Room to swing is pretty tight under there. The adjustment procedure is well covered in the manual, but in a nutshell, you loosen the large locknut and back it off several turns while holding the adjustment screw in place. Then turn the adjustment screw in by hand, counting each full revolution until it can't be hand turned any further. This is simply for reference to establish how many turns out the screw was. If you don't care, then don't bother counting the turns. Next, attach your 8-point socket and torque to the 6ft/lb setting. For the rear band, the adjustment screw is to be backed off 2 full turns after torquing. You can do this with a short socket wrench. Just be sure to count your turns accurately. For example, if you can get a 180 degree sweep with the wrench, that's good for half a turn...four halves makes two fulls. Then you'll need to hold the adjustment screw in place with a small end wrench in one hand, while you snug the large lock nut down with a bigger wrench in the other hand. Torque setting for the lock nut is something in the range of 30-35 ft/lbs.
For the front band, the procedure is essentially the same as above, except the turns out after torquing is 2 and a half (2.5).
Make mental note of the fluid color, smell and presence of obvious contamination. Also note the amount of shmootz both on the filter surface and resident in the fluid pan. Some sludge and friction material accumulation is normal and to be expected from a trans that has not been serviced in quite some time.

[Thomas]

---Your not going to get a vehicle that runs on 8° or 0° (depending on design) running right if it's timed at 10°… there's no timing chain that stretched, no aftermarket ignition, no wider than OEM spark plug gap. Set it @ either TDC or 8° and if while tuning it walks out, put it back! Advanced timing & inexperienced carb tweaking will cause excessive heat, which leads to big boom that will easily be blamed on the engine being old. Foresight beats hindsight.

---If new points, gap them as new and set dwell. If old, gap them as old & set dwell.

---While I love & always have, the Holley modulars, a disassembly, cleaning & inspecting of the 2100 you have is not a waste of time or money. What would happen if the carb was torn down, old gaskets saved, cleamed, inspected & if found good, a rebuild kit & a few extra alcohol-rated parts purchased? Just make sure you match the old gaskets & compare to body parts to enjisure old gaskets were right. Surely not the spending of needed $300+.

---I don't know if I mentioned in this thread, wasting money on parts you don't need. The non-tech garbage that resulted from roostering, hid my earlier suggestions & my reloacating made it easy to get lost in the pages that followed in my absence, but this is what I have seen in this thread, running around poking and prodding & buying this & that. All good intentions noticed, but troubleshooting doesn't require $$$ if troubleshooting is done right. Took a couple pages of clutter to get you to find 8° BTDC & time off #8. Glad you ditched those champions though! Autolite 85s are fine as long as the electrodes are centered. Timing light can be used on every wire to are if one or more plugs are misfiring.

---The image of your plug shows rich mixture, not lean. Backfire is timing or lean l. Set timing & move to carb. Idle is determined by carb design not CID or make/model. The list number & book specs will determine RMPs. Either way above 750 is to high.

---Idle screw should just barely (1 to 1-1/2 turns from closed) open the throttle plates to introduce the idle circuit to the venturi. Anything more & you can* start siphoning.

---Screw the idle mixture screws in all the way while the engine is running and if the power valve if damaged, the engine won't stall cause it's getting fuel from somewhere it shouldn't. The power valve is the same for the 2100 as the Holley modulars. Part numbers for those are in my post in the useful part number thread. Adjustments made this way atart with 1/4 turns each & when vacuum drops, turn in 1/4 turn each & adjustments made 1/12 turn follow till vacuum drops & back off 1/12 turn. Screws should never be more than 1/2 turn different between the two. Even when turning them in to check the power valve.

---Another way is the ol'-timer way of turning them out 1/2 to 3/4 turns & short cranking (3 seconds) & opening then 1/12 more... until it starts up. Then use the vacuum gauge & fine tune 1/12 turn till vacuum drops and back off 1/12 turn when when it dies.

---Brass float can be found here and from many carb parts dealers/rebuildets
http://www.carburetion.com/ford2v.htm. Float is set with top cover off if need be & gasket is new and/or doesn't tear.

---Install only alcohol/ethanol-approved soft parts. A marine kit, if available, might even contain them. Ask a local boat mechanic. Ford had many boat engines.

[scoutboy74]

Originally Posted by Thomas

---Your not going to get a vehicle that runs on 8° or 0° (depending on design) running right if it's timed at 10°… there's no timing chain that stretched, no aftermarket ignition, no wider than OEM spark plug gap. Set it @ either TDC or 8° and if while tuning it walks out, put it back! Advanced timing & inexperienced carb tweaking will cause excessive heat, which leads to big boom that will easily be blamed on the engine being old. Foresight beats hindsight.

That's utter nonsense. Only TDC, which is 0 degrees, or 8 degrees BTDC? Nothing else at all will even allow the engine to fire? BALDERDASH! TDC is a starting point following a distributor install. And how far is 8 away from 10? Let's see, complex arithmetic here...pi times R squared...carry the 1...no wait. It's two degrees. JUST TWO! No timing chain stretch, if there even was one to be stretched. No spark plug gaps wide enough to drive a Loadstar through sideways. I cannot for the life of me comprehend why you feel it necessary to over-complicate every subject under the sun.

[scoutboy74]

Also, I never indicated that rebuilding his present carb would be a waste of time. I did postulate that he would be better off in the long run to go with the new option. Josh asked if sourcing an OE carb (Holley 2210) from a junk yard would be a waste of time. Absolutely yes it would. For one thing, just locating one would be difficult enough. For another, when it comes to junk yard carbs, generally they are just that...JUNK. Reading is fundamental.

Another thing, his dwell is at 30, which is right smack in the middle of the range for a V8 engine. No need for him to retrace his steps there. He's not going to get that any more perfect than it already is. BTW, have you listened to the videos he linked of the engine running? Doesn't sound too bad for an engine that shouldn't even be firing at all. Josh, you can go ahead and retard the timing the miniscule 2 degrees from 10 to 8 if you want. Your engine will still pop and fart just as much. Your issue isn't dwell or timing. Its fuel related.

[Thomas]

-ScoutTech,

---Sorry, was going to post a more detailed reply last night, but an incoming call dropped my mobile net & caused the page to refresh... and no text One more suggestion since you might be set on purchasing the NGK/Motorcraft plugs, and will be removing all the Autolites... and even if you decide to keep the autolites; You have the syringe & MMO. Do a wet test. fill the syringe with 30cc/ml of MMO & squirt it into a cylinder then do a compression test on that cylinder & record the reading next to that cylinder's previous standard test result. Move to the next & squirt oil, etc., etc.,

---Also, a hold-in compression tester's results are not accurate. A thread-in type will not be as likely to give false readings. Don't know which you used. Last step would be a leak-down test, but a lot can be told from standard and* wet testing, possibly making the extra tools unnecessary. A bad ring could cause a miss as well as erratic vacuum reading. Need to add a wet test to the readings.

---Also forgot to mention what I may have suggested before, that if the air cleaner does not have provisions for a tube to the flame arrestor, it needs one, tee a line from manifold vacuum to the vacuum tester & hook the PCV valve back up for vacuum testing. Both these very much could eliminate the backfire/sputtering. Need a correct crankcase venting for good vacuum.

[Thomas]

---Good read