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A little motor work, and everything else too!

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No pun intended, but I work on truck engines all day.A few years ago, I got an old B-1 from club member Bear. I finally got a chance to try and get it running a few months ago. I pulled the motor, cleaned out the mouse house, went through the carb, checked the points, put on an external coil, and ran it on the bench. Ran good, after about 30 seconds I shut it down and called it good. Bolted it back in and took her for a test drive. The motor ran for about a minute, long enough to get to the bottom of the hill behind my house (of course) and then quit. Tried it a few more times, came to the conclusion that the engine would quit once it got warm, cause it wouldn't start again till it was stone cold. It also had a terrific oil leak at the front crank seal- running, not dripping onto the ground. I thought that was kind of odd.Anyways, I parked it out back and forgot about it, till I got the bug again the other day. So, I pulled the motor out again, washed it, and took it down in the basement to give it a good once over.First off anyone know what the rubber is for on the flywheel? Is it even supposed to be there?

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While I was taking stuff off, but before I opened the crankcase, I turned the motor over and there was a tremendous amount of air coming out of one of the bolt holes in the crankcase- so much so it whistled. Lots of crankcase pressure for some reason.Well, heres the breather tube. It was so plugged that I couldn't blow through the vent until I ripped the entire tube out.

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That explains the monster oil leak.I thought maybe the points plunger was sticking in the bore, but plenty of side clearance there.

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Sure was a lot of carbon in the intake side...

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No metal in the oil pan, thats a good sign.Popped the head off, she ate something pretty hard at one time..

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The piston skirt and cylinder wall look O.K. According to Jacks, the .010" over piston is NLA, so a hone and some new rings will do.One thing I noticed when taking this engine apart was the crank had about 1/4" of end play, which is a lot. So much so, that I think the counterweight from the crank hit the cam lobe.

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I see in the manual they say if you can't get the correct end play with the thinnest gasket they make a shim to install as well. I think I will order one of those right away.The exhaust valve is pretty gummy, had to actually pull it out rather than it sliding out easily like the intake side. This could have stuck once warm, thats for sure. Will have to wire wheel the valves real good to free them up. The seats and margins look O.K. so I think some lapping will suffice here, as well as setting the valve clearance.

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I have the correct valve spring compressor according to the manual, but it doesn't fit and I wound up compressing the springs with a needlenose and popping the keepers out with a pick. Haven't figured out how I'm going to get them back in yet.Heres a handy way to keep parts organized- we get rebuild kits for Jake Brakes at work and I always save the boxes. Then I write what the parts are for in the bottom of each compartment and things stay nice and neat.

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So, I looked up prices on Jacks, for a ring set, two crank seals, a breather tube, a gasket set, points plunger boot and crank thrust washer comes to about $70.00 . I'm hoping my local dealer can come close cause I like to shop local, but a nickle is a nickle and a dime is a dime, if you know what I mean.By all means, the reason I made this post is to give anyone some ideas that may help, but also to garner advice from the experts. Let me know if I'm doing something wrong or if you have any recommendations. This is a low budget rebuild, thats for sure. I see the cam is still available, and its only like $35.00, but I haven't made up my mind on that yet.Thanks BLT, for taking the time and getting me all the manuals I need. Knowledge is half the battle.Thanks for looking!












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Thanks for sharing all of the great pics and discriptions.

I will be interested in the longevity of this motor after your rebuild. I give you kudos for saving this engine with all of the issues it seems to have. Best of luck on your rebuild.

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Have you given thought to plugging the plunger hole and going with a module like RayS sells ?

Also, Have you given thought to chrome rings ? They are supposed to seal past the wear point of regular rings I believe.

Good luck. I look forward to hearing how it turns out.

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I don't think I can use a Mega Fire with an external 12 Volt coil, can I?

I am not sure how a Mega Fire even works, truth be told. Doesn't it get its signal to fire from the small wire from the mag? The original spark plug wire was pretty much chewed off on this one so I'm just going with an external coil.

I cleaned up the piston, rod, crank, and cam today- all looks O.K. I think that cam will run a long time, I'm going to try it. The face of the tappet that rides on that lobe is fine. I ordered parts from Jacks today, should be here early next week cause they had to order a few things. Run a hone and lap some valves this weekend, clean up the rest of the parts, and we should be going back together.

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Forgot to mention its not the original engine- its an 8 HP repower.

I was torn between a full rebuild and just getting it going again. If I had a 19D I would give it the works, but for this engine I'm just going to patch it and let er rip.

Once I get a running motor in it I have to replace the axle shaft seals on the tranny and figure out what the horrible clicking noise is in the differential when I turn, then I should have a working FDT to play with.

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Make sure to check your piston skirt and ring lands thoroughly for crack formations. I have lost one decent runner and almost lost a good runner to piston cracks. With as many pings from hard things as that piston head shows, it's a concern.

The latest time I found that was in an engine that ran fine no smoke but the comp ring was in 4 pieces and the skirt was cracked in 3 places so dramatically I could shine a flash light through them. Scary.

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I see where you said you used an external coil. Guess I just assumed you had done so to get it to fire and that the original coil was still on it.

Myself, I don't understand changing to battery ignition. You have the cost of a switch to factor in and from that point on your bound to a battery. While it isn't my favorite thing to do, I can got out and start any of my Briggs engine tractors with a rope, without a battery.

The weak part of Briggs ignition was IMO always the points and not the coil. The module gets you free of that but going to battery leaves you with them. Now you have two negatives. (Again JMO)

Will the modules work with a 12v system? Not that I know of. As to how they work, When you put DC power into a coil, It becomes locked and can not move forward without a "Break" This "break" is made by the points. The module does this without moving parts and without contacts to burn or corrode. The dwell is built in so you never have to "Set the points" so to speak.

I believe the reason these mods won't work with points is that you don't have a trigger. Nothing tells the module to do its thing.

The chrome rings are a factory offering. Order for the piston size. They have much better spring and so keep better contact with the cylinder walls. They also seem to be harder to stick in a worn bore. All in all, they get you more time out of a worn engine. Its been years since I last bought chrome rings but when I did seems like they ran about double the price of iron. Maybe 15 bucks extra at the time?

Sorry for the long reply...(

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I have 3 tractors currently with a 12v ignition...2 came to me that way from previous owners, and 1 is on a 23D (finding a coil for that is bad enough, but paying for one is terrible). I like the spark they give and have no complaints. Rarely is a tractor without a battery, and even with an old dead one in there, you can start by rope if the need arises. I have not found old points to be that much of a hassle. If they don't work, clean them up a bit, and adjust and away you go.

On the other hand, I've had a few that needed new points, or a plunger was toast, and tried the Mega Fire. They are cheaper than points, and are a once and done deal, as mentioned above. No complaints and no oily mess from a weeping plunger. I go either route, depending on the circumstances. So far, I can say I've come across more bad coils than points. That could just be coincidental (mice don't eat points!)

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Hi sounds like a good project the belt on flywheel mat be rubber that was bonded to the two metal disks on drive shaft coupler original style. The crud in the breather tube may bee muddaubers{}{}{}{}{}{}{}

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Well, I got the block all cleaned up, honed the cylinder and lapped the valves, looks pretty good up top.

assembly 001.jpg

I cleaned up the cam and touched up the rough parts of the nick with emery paper, looks good, we're going to try it.Pressed in the new crank seals, installed the shim washer for excess end play, put the two thickest gaskets on the flywheel side, end play came out perfect at .002" which is way better than the .250" I had before!

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I forgot my dial indicator at work, so I made do with my calipers for measuring crank end play.

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I'd get a lot more done each night if I didn't have to stop and love up ol Charlie every time I want to stand up!

assembly 002.jpg






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Well, slowly but surely, going back together.Got the engine all reassembled, since I'm going with a 12V coil and my condenser doesn't fit under the points cover, I flipped the cover over so the slot is a drain hole rather than a water collector. Drilled a hole and put a grommet in the side to get my wire out.

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Pushed the tractor into the garage for the weekend. Bolted in the engine, found quite a gap between the driveshaft and the motor. When you pull it together with the bolts, that puts one heck of a thrust load on the crank. That could explain the large amount of end play.

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The mechanic in me immediately set to work on taking the tower loose to move the yoke on the input of the BGB.

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Yeah right. That baby ain't moving unless I take the whole driveshaft out and pull it off with a puller.Thats when the tractor guy in me whacked the mechanic part and said "For the cripes sake, put a washer in the other end and run it."So, I put a washer in the gap, and loosened the motor mount bolts so the engine could wiggle into position, seems to be O.K.

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Everything else went smoothly until I ran into the next hiccup. When I put the S/G on, I remembered that the belt stretched bad when I was testing it this summer. Great, out with the driveshaft coupler and this part is stalled till tomorrow when Fleet opens.Luckily, when I filled the tranny it all ran out onto the ground immediately via the left axle seal.So, went to work on that end.

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When tapping a seal into place that has a garter spring, I always pack the backside with grease to keep the spring from popping out.

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Tapped the seal into place, and filled up the tranny again. Cleaned up the floor, we'll look for drips in the morning.


More to come.....








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I figured I'd better change the title, cause this is going beyond just an engine job.Got the right S/G belt, after two trips. Everything I read called for a 3/8 by 36, mine needs a 3/8 by 37.So, I got it all back together, wired up my toggle switch and 12V coil, oil and gas, cranked it over, no spark.You know your dedicated when you hook up an umbilical and are standing outside in 25 mph winds trying to get your tractor going....

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Double checked everything, re-set the points, now have spark. Put the points cover on, NO SPARK.Look at the shape of the cover. When I flipped it over and installed it, it just touches the arm, grounding it out.

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See the marks from the points scrubbing on it when the screws are tightened?

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Thats what I get for re-engineering things....At any rate, it fired right up and runs great! Adjusted on the carb a little, and she purrs nicely.I figured I'd better put a load on it to break it in a little, about all I have for a load is a lawn sweeper right now, better than nothing.Hop on my trusty steed to go do that- IT WON'T MOVE!!! Something is wrong with the diff- it just spins and neither tire turns.Geez, I feel like that guy in the myth pushing the rock up the mountain- what was his name? Allis Repairus?Well, lets learn about diffs now- I've never monkeyed with one.Took the right wheel off, the collar, and the hub/gear.Found two keys laying in amongst the gears-

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I think what happened is last night when I was doing the left axle seal everything got pushed to the right, and these two keys fell out.How do I go about getting them buggers back in?I think I'm going to have to disassemble the diff, put the inner stuff on, then the side gear, then the outer case?There was a clicking noise when turning and some of the bolts are loose so I'm going to go through it anyways, I guess.Any tips would be appreciated.






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Well, got the diff straightened out. I took the left collar loose, then pushed the axle shaft to the right. That gives you room to put the keys in, then the gear and three keyed washers, then the snap ring. Got it all back together, O.K. now.

Hopefully tomorrow I can break in the engine a little...

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O.K., popped the differential off tonight, I noticed when I turned some of the little gears they didn't mesh correctly.Upon disassembly, I found most of the 3/8" bolts were loose. Uh Oh.Think I found the problem-

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My best guess is the loose bolts wore the holes oblong, which allows the planetary gears to move away from the sun gears, causing grinding and jumping and general tractor-not-movingness.Fix this little problem and the leaky fuel tank and we will give it another shot!




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So, I plug welded the four offending holes shut, sanded the surfaces smooth, and used the cast iron inner hub as my drill guide, to redrill the holes. A little sandblast, primer, and paint, good as new!

diff assy 001.jpg

Cleaned up all the parts, only one of the little gears look a little rough, but I filed all the sharp stuff down, should be O.K.

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Coated everything with fresh grease and reassembled.

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A few well placed gobs of grease.

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Everything turns smoothly now, put it together with lockwashers.

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Getting pretty learned up on diffs!

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Also took the fuel tank in, they resealed the seam, leak tested it, sandblasted and primed it for me, so I threw some paint on it, which, by the time I got the straps back on, was a little scratched up. Oh well.

diff assy 1 003.jpg

SO, we will try it again, when I get a chance.Thanks for looking!








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Nice work!...and documentation...Thanks

I've got a B1 resto slated for this winter. I'm sure I'll be refrencing this thread as I go along as that little engine is a bit diff than all the larger briggs I've done. sm01

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Well, I took it around the yard for a photo shoot, no more clicking when turning, runs good.

I guess I'll have to wait till spring to break in the motor.

Time for the rifle season-Thanksgiving-Christmas-fiasco.

Can't seem to post a picture right now, but I did a thread on duals in show and tell as well. Some neat pictures.


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