Autolite 1101 adjustment

[Johnsondawg]

I finally got around to installing my rebuilt 200 in my 66 Bronco with a C4 transmission. The engine is from a 68 Mustang and has an 81 200 head milled 60 thousandths to regain compression from the larger combustion chambers of the later heads. The C4 is from an 80ish fairmont and was built to merry up with my dana 20 transfer case I found a New Old Stock Autolite 1101 and got it installed. I also have duraspark II ignition and pretty much everything is either new or freshly rebuilt. The problem I'm having is getting this carb adjusted. I don't have any specs on where the float, accelerator pump, etc. should be set. I have my timing set at 12 degrees. It seems to idle great but when I hit the accelerator Hard it will stall every time even when its in park. I was not able to locate any sort of a vacuum leak using propane or brake cleaner. The accelerator pump appears to be squirting fuel in as it should. So what else could be causing the stalling? If I ease the accelerator in more slowly it won't kill it but it will stumble a bit on the way up. Can anyone provide me with some info/ specs about setting up this carb? My carb is like the one in this diagram that I found on here in another thread. http://s980.photobucket.com/albums/ae29 ... akdown.jpg

Any help getting this taken care of would be appreciated!

Thanks,
Jeremy

 

[wsa111]

Jeremy, sounds like you have no accerator pump shot.
Verify this by looking down the carb throat with the engine off & the carb bowl full of fuel & moving the throttle. You shoud see a shot of fuel shoot into the venturi area.
If no fuel the check ball is missing under the weight in the accerator pump circuit or the diaphram is leaking. The pump stroke is also adjustable. Bill

 

[wsa111]

Jeremy, sounds like you have no accerator pump shot.
Verify this by looking down the carb throat with the engine off & the carb bowl full of fuel & moving the throttle. You shoud see a shot of fuel shoot into the venturi area.
If no fuel the check ball is missing under the weight in the accerator pump circuit or the diaphram is leaking. The pump stroke is also adjustable. Bill

 

[Johnsondawg]

I know that I have fuel squirting in from the accelerator pump but maybe its not enough or too much? I tried adjusting it because the accelerator pump seemed to have a slight lag when I moved the throttle by hand. Even though the carb is new, I'm thinking about rebuilding it. Maybe some of the seals are bad or the accelerator pump is leaking internally (No leaks on the outside of the carb). I'll look for the check ball as well. It seems like the information on this carb is not easy to come by. Any further help/ suggestions are much appreciated.

Jeremy

 

[CZLN6]

HOwdy Jeremy:

A couple of questions first- The carb in the diagram appears to be a '69 type with no Spark Control Valve (SCV). Is that the carb you have? IF so do you have the vacuum to the distributor hooked to a ported source? What is the elevation where you are in Colorado?

Ok, I'm going from memory now as I don't have sources nearby, but I seem to recall a white plastic lever, under the float bowl, on the throttle shaft, opposite the linkage. It connects to the accelerator pump actuating arm that works the lever on the accelerator pump. That white plastic lever has two holes on it. My recollection is that one hole is for Higher elevation and warmer temperatures, the other is for cooler weather and possibly lower elevations.

First determine if you have a earlier 1101 used on the 223 sixes in 1963 & 1964, or the Non-SCV version used on the '69 250 engines. IIWY, I'd then buy a rebuild kit specifically for the instruction sheet. The sheet will give you critical info on the accelerator pump settings as well as float levels.

IT is a good idea to disassemble the carb just to ID the jet size and to check the float setting. It is good to know where you are to start with. Another thought is that the bent link from the throttle lever to the accelerator pump could have gotten bent out of shape at some point in its handling or shipping.

Sorry, no big help from me. Just some thoughts and, as always, more questions.

Adios, David.

What carb was on this engine previous to the 1101? How did it run?

 

[Johnsondawg]

My elevation is under 5000 feet but not by much 4900 ish. The carb is the one without a spark control valve. I looked for that because of the duraspark conversion. I do have the dizzy hooked to a ported vacuum on the carb. I had the same idea about the rebuild kit. Also I was thinking that the accelerator pump diaphram may be bad just from age. Thats also a good idea about getting the jet size. If I needed to change the jet, is there a source for them? I'll grab a rebuild kit and report back.

 

[Johnsondawg]

I MAY have found my problem. I was missing the HI LO roll pin on the accelerator pump and the measurement of 3/16" for the accelerator pump was taken at the actuating arm not the roll pin. So, long story short the accelerator pump was not really squirting much fuel. I need to finish setting the carb up and get it installed to see if it works.

 

[CZLN6]

Howdy Back:

Good catch Jeremy. Keep us posted once you get it back on and going. Did you check the main jet size while you had it off? At your elevation you may need to down size a step or two. Jets are available from Pony Carbs, but they are pricey. Once you know what is in there post here for one step smaller. Then do a plug check. The shop manuals also recommend an additional 5 degrees of initial advance for locales over 3,500 Ft. That should put you in the 12 to 14 region if I recall the stock specs correctly.

Adios, David

 

[Johnsondawg]

David, The main jet has "70 F" stamped on it, don't really know what that means. I got the carb together and back on and it was improved, however, it still had some stumble when you hammered the accelerator. I pulled it back off and adjusted the accelerator pump arm further out so it would push more fuel. That helped the stumble quite a bit. I think it still needs some tweaking but its closer. I did notice that when I back down my driveway , I had a few occasions where it stalled. I thought it was happening when I went down the curb but I'm not sure if thats the cause. Maybe it just was not warmed up yet. I still need to work on the choke a bit more. I thought I had set the timing at 12 degrees before I pulled the carb off but I discovered after I pulled the carb off a second time that it was only at about 2-4 degrees. I reset the timing back to 12 and it ran the best it has so far. I wish I had caught the timing issue before I readjusted the accelerator pump. I'm wondering if I should move the accelerator pump back to previous setting now that the timing is advanced to 12-14.?

 

[CZLN6]

Howdy Again:

The 70 jet is pretty big for a 200 application. But, I wouldn't change it until I had all the other issues pretty well worked out; Accelerator pump, timing, choke and low speed idle. Once that is sorted out, I'd start to assess the main jets richness with a new set of spark plugs and reading the spark plugs. Make sure the choke is all the way open and you have the opportunity for a fairly long, high speed drive when you do this. Since the 1101 was designed for a larger engine than your 200 it will likely be richer in some internal circuits that are not easily altered. But you can do quite a bit of tuning with the low speed air screw, float level, choke setting and accelerator pump before changing the main jet.

Late initial advance will certainly add to a bog. I wouldn't hesitate to play with timing advance all the way up to 16 degrees at your elevation.

Keep it coming.

Adios, David

 

[Johnsondawg]

David,
Thanks for the help. The plugs I have are new, I replaced them last week along with the cap, rotor, coil, and wires. I'm going to try bumping the timing to 16 and see how it runs, What about the accelerator pump? I was surprised how much I had to open it up to get rid of the stutter. Should I reset it back to where it was now that the timing is advanced? I picked the 1101 because of the throttle bore size that matches the Throttle bore of the later 200 head I'm running. Is it just too big or or am I going to be able tune it for my needs? I have two 1100's. One is for the old 170 (manual transmission) and the other was from the 68 Mustang 200 ( Auto ) that one is the carb that was on the 200 when I got it and before it was rebuilt and the late model head added. I would like to keep the 1101 because I made custom throttle and kick down linkage for it. Maybe one of the other carbs has a more suitable jet that I could swap into the 1101 for better results?

Jeremy

 

[CZLN6]

Howdy Back Jeremy:

The 1101 should be fine. I ran one on my 200 before going to the 250. You might want to play with the pump lever. I'd try to reduce the pump shot to just enough to get a smooth acceleration. The 1101 is rated at 210 cfm as compared to pre '68 200 @185 cfm. The 1101 is my favorite for a 200 performance upgrade. Yes, be sure to grab the jets out of the 1100s as possibles.

Both your 1100s are down sized in cfm; The 170 because that's what was normal for them and the '68 because FoMoCo downsized the carbs on the 200 in '68 & '69, when they went away from the LoM distributor.

Adios, David

 

[Johnsondawg]

David,

I was occupied with the Family today so I was not able to get much done on this. I will pull the carb back off tonight and reset the accelerator pump back to the original settings. Hopefully that will work now that the timing is back where its supposed to be. What is the next step down in jet size from what I have?

 

[CZLN6]

Howdy:

The mark on the jet is a reference number, and not an indicator of flow capacity. Autolite jets are not interchangeable with Holley jets, which are numbers to correspond with flow. The Autolite jets at sequentially numbers from a low of 40 and on up. I have 48s though 73 that I have on hand for tuning.

The next thing you will need to do is to get it running as good as possible and then watch your plugs. Reading #1 and #3 should give you a fair indication of your carbs Rich/lean condition. I'd be looking for a #68 or #67 depending on what your spark plugs show and how it drives. I try to never have to change jets more than 2 numbers up or down. If the carb/engine requires more than that, it may not be the right carb due to internal, non-adjustable circuitry. Chances are your 70 main jet would be close below 3500 ft elevation.

Adios, David

 

[Johnsondawg]

David, I spent my evening horsing around with this some more. I bumped my timing up to about 14-16 degrees. The indicator only goes to 12 so I guesstimated it a little. I also backed off the accelerator pump some. The rebuild kit and my service manual both say the accelerator pump should be set at 3/16 and I'm closer to 9/32 or 5/16. I'll have to pull the carb back off to dial it down any further. Right now it seem s to run the best it has so far. Pretty good throttle response and a noticeable increase in power. I'll put some miles on it and see how the plugs look. How much driving do you think I need to do before I start inspecting plugs? Until I can look at the plugs, I could use some advice on setting up the choke. The rebuild sheets I have tell me to bend a .036" wire at 90 degrees then " Insert the wire end between the lower edge of the choke piston slot and upper edge of right hand slot in choke housing" I can see what the lower edge of the choke piston slot is but I have no idea what they are referring to when they say "upper edge of right hand slot in choke housing". Any idea what they mean by that?

 

[CZLN6]

Howdy Back:

"No" on the instructions for setting the choke. i've never had much success with setting the choke per instruction sheet. I'd recommend setting the choke lean, or just enough choke for cold start and easy drive off. The instruction sheet gives you a general, one-size-fits-all place to start setting. It does not take into account the climate or weather at each and every locale. Also every engine is a little different in what it needs for start up and cold running. I start off with a cold setting of just enough choke so that the fast idle cam is engaged and then do a start up and drive off. That setting is usually close to the middle setting on the black choke cover- maybe a mark or two toward the lean side. This setting may work fine in the summer and fall, but may not be enough for serious winter. When it is not enough I add a little more and try it. The problem is adjusting the choke is that you will only have one opportunity each morning to try a setting. But, it usually only takes a morning or two of cold starts to get it right.

My idea is to set the choke as lean as possible, which is better for fuel economy as well as for minimizing fuel wash and oil contamination.

Adios, David.

 

[Johnsondawg]

Thanks David,

I forgot to mention that I opened up one of the other 1100's i have to see what the jet in that one was and that jet did not have any markings on it. Have you ever seen an unmarked jet? The carb it came from has a "reman" sticker on it but the sticker gives no indication of jet size that I can see. I'll check out the other 1100 I have and see what it says.

Jeremy

 

[Johnsondawg]

I took a closer look at the other two 1100's I have and found the jet sizes to be a 61 and a 63. I'm sure that it is running richer than it should but a 61 or a 63 would be a pretty significant step down from the 70 that I currently have. I was thinking of stepping down to a 68 and seeing how that works. Is that reasonable or should I consider stepping down further?

 

[CZLN6]

Howdy Back Jeremy:

Nope, I've never seen an unmarked Autolite jet. Some are hard to read. It should be stamped on the top.

You can start to check plugs anytime. Get several readings; highway speeds for 20 minutes or so, as well as city driving or off-road. Just make sure it is run for 20 minutes or so with the choke completely off.

IIWY, I'd try the 63 jet, just because I had it. To assess whether it's too lean, drive a highway at 50 to 70 mph- steady. If it surges, if it doesn't hold a steady engine speed, it's too lean. If it is, then you've narrowed the window in finding a just right jet. If it doesn't surge, again watch plug conditions.

Another thought is to use a one step colder spark plug heat range. I buy the cheapest plugs from a name brand and change often. One step colder in the summer months and back to a hotter heat range in the winter. Just a thought.

Adios, David

 

[Johnsondawg]

Thanks david, I'll go take a drive and then get a read on my plugs this afternoon. After that, I will swap the jet to the 63 and try again. I'll report back with what I find.