well basiclly he has a modern version of a model 8, which in old school would have been a 2 3/4 hp. I went out and looked at one in the shop that used an airvane system, and its all linkage and springs that he's missing. We need to get the vane connected to the carb arm and it has to have a control spring for it to pull against. On his orginal engine it had a pulsa jet type carb with a vertical shaft. We now have a horizontal one. not sure if we can do this with the existing vane as the arm may wrong. What would be ideal is to find the parts from a 8S, as it would be similar, just 20 yrs olders.
David Bradley Project!
Posted January 01, 2013 - 06:56 PM
Posted January 01, 2013 - 07:39 PM
i think the carb will work as there was only a small, medium and large flow jet ever built. You wont find the large on any smaller engine, most of the N models used the small. I was thinking that the small would work out on an engine of not bigger than 3hp, and then you have to move up to the medium one.
we need to know just a little more about the engine your carb came from,ie was it an airvane or mech govern'd. One thing i noticed in your picture was the solid fuel line going from the carb to the tank. This is the way the factory built them, but time has shown us taht the tractor viberates enough that the line will crack sooner or later and leak fuel on the motor. I subject that you cut the copper line and install a short(3") piece of rubber hose and clamps,into it.
The adapter you made is cool , but it may cause us trouble getting the carb and govern hooked back together as it has moved the carb away from the engine block and the linkage may be hard to make. you may have to replace the vane with one from the older engine, and might have to lengthen the arm out some. I also see the throttle control area is differnt and you will need to get the sliding part install. i'll try and get you a picture of what it should look like, in the morning, as its only 9* out in the shop right at the moment.
Posted January 01, 2013 - 07:46 PM
Well Lauber, you won't get rid of me that easily. No, I may not post as avidly as some of the experts here, but I probably won't be building dozens of tractors either. I do appreciate all you guys here, and your wealth of information. I may not know as much as you about the tractors, but, I do have the dilemma of what will a non-builder be able to understand, and stay with. If I got too far out in the weeds with highly pertinent details, I would lose the wanna be beginners. But, perhaps you could shed some light on what parts you felt were important but not addressed, and as I build the second tractor, I could put some 1 minute episodes together to address those topics. As for the pictures I used- first I looked for images with no copyright info. I would be happy to put courtesy notes with the owners names in, but I have no idea who they are. Do understand my dilemma though- I had to illustrate where this was going, with no finished product to photograph. I would very much like to have tractor experts involved in the show- but right now I have no budget to fly these experts in. This is one thing I would like to do in the future when the show has some good sponsorship. Let's see how that goes. In the mean time you will be stuck with me figuring it out as I go. Fear not- the gas cans had no gas in them, in fact I used them to hold antifreeze after a bottle ruptured. I agree though- the average viewer does not have that information when they view the video. Slowly, my garage is turning more into a decent workshop, and less of a catch-all. I plan to address garage organization and safety in the future. You may notice as the episodes progress that the garage gets cleaner and more organized. I will use this in the future. Sorry for my absence! I was busy making money and other mundane tasks. By all means, let me know what you think will make the show better. Currently, I am finishing the last 3 episodes of the DB project, and then we will have a mini project on tilling the land with it and planting a garden. Future subjects related to garden tractors will include food preserving and gardening. We will build other things as well- I am planning to restore my Delta table saw (I have 2 of those too, so some photographic slight of hand may happen there as well), doing some wood working projects, some mechanics projects, perhaps building solar panels from scratch, and this one I thought was interesting- building a gasifier to run an internal combustion engine off of wood. I even saw where a guy made a small one to run his lawn tractor. Any projects related to tractors you would like to see in the future? Thanks for looking at the show.
You've taken on a big project. It all takes time and adjustments. Just keep going until you are satisfied with it. I am interested in the gasification. My father saw a lot of it in England during WWll. I saw a sawmill in North Carolina that ran off the smoke from burning the slabs. Mother Earth News Magazine had plans for building a setup. Good Luck
- sdevine said thank you
Posted January 01, 2013 - 09:20 PM
I think the fuel line would be better if you made a loop in the copper tube instead of the rubber hose. It will accomplish the same thing and give it less places to leak from.
- Lauber1 said thank you
Posted January 01, 2013 - 09:35 PM
yes a loop could also be used. I like the rubber as i ussally put an inline filter/valve on in place of the orginal bowl systems which always seems to leak. I dont think there is one perfect system for fuel handling.
Posted January 01, 2013 - 11:21 PM
ok im going to try and post the page out of the briggs book, where it shows how to setup the air vane governer assembly. Not sure if you will be able to see it, but it shows the rod, spring, the arm and all of it hooks to carb. I also emailed a couple of people who have done the exchange from a suction carb to a flo-jet to see if they had some good pictures.
- tractorman604 and sdevine have said thanks
Posted January 02, 2013 - 10:35 AM
On the fuel line, with the extension necessary for the new adaptor, I made a new copper one based on the one I had plus the extra length. I have more copper pipe to make one with a loop, that sounds like the way to go. The bowl filter system does look like an area that might cause grief, so I will keep an eye on that. The page is a little hard to see and doesn't blow up far enough to get a good view. So, here is my thought- I could solder an arm extension on the air vane, then have a spring attaching it to the throttle arm. That will take care of the airvane portion of the governor, then I will need to attach the throttle cable to the other side- but a direct connection will not create the 'tug of war' scenario needed to make the governor work. On the third picture, you will see that I have a bracket of some kind on the case- I thought this might come in handy. Perhaps a little arm attached there with the throttle cable on one side and a spring to the opposite side to the throttle arm? Now that I think about it, there may not be a good reason for a spring on the air vane side. If this is the case, the question becomes what are the correct settings- where should the air vane be at rest? what am I looking for as far as tension on the spring, and is there a way to tell where the throttle position is supposed to be when the engine is not running? The old motor I believe is an N model, and it has a mechanical linkage that attaches on the side of the motor with- well- let me just attach a picture---
Edited by sdevine, January 02, 2013 - 10:39 AM.
Posted January 02, 2013 - 10:55 AM
At rest the throttle should be wide open. You would want the spring to work between the throttle cable and the carb. you might have to experiment with the spring tension but your not going to want a very stiff one. The air vane has to be able to overcome it to shut the throttle.
Posted January 02, 2013 - 01:45 PM
okay your old engine in the picture looks to be a model 6, with a mech governer. It might be an 8, as there are pretty close to the same by looks, but its not an N as they would have had a smoother curved fan cover, instead of the squared off ones later engines used. I posting you some pictures of a junker model 8 i have here, that used the airvane gov system. As you will see you are missing a lot of the things that makes it work. Not sure how we will get there but the vane arm need to at the level of the arm on the side of the carb, then it needs a little bell hook to connect the 2 items. If you look into the picture you will see a slider that the throttle cable hooks into and a main spring that keeps the tension on the slider plate. At the front side is a little knob where another spring hooked on and went up to the arm of the carb. This spring gives the vane something to put against. The spring is missing here because we dont have a carb in place.
In your picture i see the arm of your vane is straight up, which would be correct for the pulsa carb that would have been there. Look at my pic's and your vane need to look closer to the one there. Notice how it bolts to the side of the mag, the arm is low and pointing stright out towards the carb. This will be the biggest item for you to work on, or else there will be no gov control. We need to get a clean, smooth, control rod hooked up between the vane and the carb.
Now lets talk a second about your other engines, what is wrong with them, why do you think they need parts. If your tractor was a 561 it would have came with a cont-AU-8 engine, a 560 would have used a model 8 briggs. A lot of tractors used the briggs units when the cont's crapped out, and since the "8" is almost a 3hp engine, why dont you go that route? Not saying this is you, but a lot of guys look at an old dirty engine and freak out, thinking it junk or that will take a lot work to run. A dirty engine is just one that needs some loving. Most engines dont run because they are dirty, and when you clean up all the bits and piece and let the parts work together right you get where you need to be. Since you have put a lot of work into this project, why not go the extra step and complete an engine for it, under a whole differnt chapter. I think i saw part of a preview of you cleaning the current one up, so you were already half there.
- tractorman604 said thank you
Posted January 02, 2013 - 03:17 PM
So it sounds like my existing air vane will not provide the necessary governing on the carb? Let me study what you wrote here and see. I have 3 other engines- the one in the picture is a model 500 108042, serial number 359356; the second is a 500 108041 serial number 567457; the third is a model N type 306137 with a serial number of 809700. I was under the impression that all of these were only 1 hp. None of them have good rings, so there is no compression. I had a gasket company make head gaskets for the second and third ones, the N model is missing the flywheel cover, and who know what else- it came disassembled- the #2 500 looks mostly intact, and is the one I was cleaning in the video, I believe. It is mostly together. The 1st came off that DB brush cutter contraption I got along with the tractors, and is in tact. Probably new rings and a good going through and it will run. My plan was to use that one and change the flywheel cover with the other 500 that doesn't have the extra piece on it. I do have an engine rebuild episode about half done which should be the next episode- but I have to finish an engine to finish that episode. Then the current engine came along, and we thought it was more powerful, so I did a switch. So, you think it will be easier to finish the original engine then to make a governor? Can you give me a lead on rings? The local lawn repair places are less than helpful and say they don't have it. The parts frustration has been fairly high, so this running engine was a relief to all of that. I could put the suction carb back on but the tank is rusted badly, and I did want to keep the style and use of the gas tank on the tractor. My suspicion was the suction carb would take more modification then warranted. Okay, question- What if I ran the throttle cable direct to the throttle, and skipped the governor all together? What consequences would we be facing?
Posted January 02, 2013 - 09:30 PM
Ok, so lets go outside the box and not talk with the mower shop people, who are less than helpful. Let get out into the net.................a place where we can find real on time answers.
Here is all the gaskets one would need to work on a briggs N or 6 and probally a model 8 as well. The rings would only work for a n or a 6.
Sometimes you dont have any compression because you have a valve issue and not a ring issue. This all goes back to the dirty engine thing. Carbon builds up on the valve head and seat and they dont close properly. Most times they just need cleaning, some times they will need to be lapped. These parts come from a company called Prime Line and you can buy them right over the net, or go to the mower shop and have them get them, as thats were a good deal of their stuff comes from. I just got these from my briggs dealer last summer.
I wouldnt junk the current engine your doing, just put it back until you can come up with the parts needed to make it work right. You can do it, but not in any quick manner like i can here with 20+ yrs of engines and parts to fall back on.
The N and model 6 briggs are basiclly the same engine engine on the inside, the sheet metal parts are differnt on the outside and both come either air or mech governed. The HP is 1.6 for either one, and 2 1/4 to 2 3/4 for a model 8. Even with a 1.6 hp engine it would take a big man to hold back a DB under power. Lets take a second here for a word of WARNING..................
The clutch on a DB tractor is prone to sticking, dont start the tractor up inside the building ,were you could get trapped by it. If the clutch sticks and the engine starts, you WILL be ran over, and its going to hurt. Alway start one in a place where you can step off to the side away from the tractor. They are not toys, only machines, and will do what machines do if your careless,,,,hurt you.
So with the proper parts you should be able to take the engine aprt and clean it up and reassemble it to running form. Dont go crazy and take off every nut and bolt, ussally there is no need to remove things like the crank and camshaft. Just pop off the head and the base parts clean it all up, get the piston out and make sure you pay attention to hows it in there, ie which side of the rod faces the cam shaft, install your new rings, rebolt the piston, reassemble the base and head parts, then it mostly just reattaching the carb and small parts, adjusting and starting. You may also need to hone the cylinder walls when the piston is out, which is another easy to do thing. You will find having some special tools...................
Its to bad you live so far away, as we could do this all in a long day right here in my shop.
- tractorman604 said thank you
Posted January 02, 2013 - 09:34 PM
i forgot to answer the throttler part. without a way to control the rpms, the engine will either stall out under load, or blow up due to to many rpm's. Thats the reason for the gov, to control evenly the fuel flow, and rpm.
Posted January 02, 2013 - 11:41 PM
Okay, so I am thinking that we will leave the green motor on the tractor for now, and work out the governor. Were my notes correct on setting up a linkage? I will continue to build the N and the 6 so I can have them for the engine rebuild episode, and perhaps swap them at a later date, or use them on other projects. I do have a second tractor to power. I was already planning to hone the cylinder, that is a good idea. Warning duly noted. I loosened the clutch plate a little more to make sure it would spin free before I started the tractor. Just for clarity, the engines with the 500 number- those are 6's right? I will talk to Prime Line for the missing parts. Perhaps in the future, we can take a field trip and see what is going on in your shop. We would like to be able to do this in the future, and feature other peoples projects. Perhaps I will set the N aside for that....
- Lauber1 said thank you
Posted January 03, 2013 - 12:32 AM
Yes your soldering on an arm to the vane might work out,(or you could use one the products from a previous show). All it has to do is stick out towards the carb, at about a close to height. you will still need to make some kind of linkage, and you will have to have some kind of a spring involved so the vane can move free via the air from the flywheel. You could just put a lite spring on the end of the throttle wire and hook it into a hole on the carb arm. It will be crude but should work out.
For clarity......500 is the number Sears assigned to all Briggs parts and engines. It is there vendor number. The number 500 didnt mean anything to Briggs other than that. The 500 number can show up on any brigg item, not just engines. 917, is the number Sears assigned to DB for any parts, or other items built at the factory in Kankakee,IL, which is the home of David Bradley. Some where in here and out on the net is fairly complete list of Sears assigned vendor numbers.
You can come field trip any time you would like, just give me a couple weeks notice so i can sweep the floor. We have tractors here from 1933 to 1965, mostly walkers, but there are some riders, and we are very heavy on DB/Sears products.
- Alc said thank you
Posted January 04, 2013 - 01:15 PM
To help you out some more i found this picture of what it should look more like. Notice the large L shaped rod. Not shown in the picture is where the throttle wire would hook to the bottom of it. Also notice the spring that lets the gov do its thing. You need to get someplace similar to this and it will work great.
- sdevine said thank you