OT- Need help with a Briggs engine so the old Cushman can keep putt-putting along

My bet on the valves are, Exhaust 390419, intake 299884. This exhaust valve uses the tapered keepers, similar what is used on automobile engines. intake uses the simple "keyhole" style retainer. Head gasket 270430 Valve cover gasket 27803 intake to block gasket 27828 Intake clearance .006" Exhaust clearance 010"

Greg

Thanks, Greg. I saved a copy of the PDF.

When I bought the later model block, I was needing to replace a 68 engine with a big sand hole in the bore that opened up during honing for a re-ring. If it had been lower, no problem, but the darn thing was in the upper 1/3 of the stroke.

And I knew I should have passed it up for lack of a shroud, but I didn't . . .

Thanks again.

damn, Greg... I'm impressed!

Mac

What carb does it have? What starter? The model number and code are easy to determine/fake. The type will be a bit more problematic!! Any idea what it came off of??

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Greg set me a .pdf file of the complete parts list. But thanks for the help, anyway.

Btw, the original 1968 engine I had came off a Senator tiller, this one I have absolutely no idea what it came off of, except it had the big Flo-Jet carb, like my old engine.

It now has a dual circuit alternator and 12V starter from 190000 series 8 Hp vertical shaft. I love the parts interchangeability of Briggs engines . . .

Thanks again, to all.

Greg's another small engine mech in the group. I just couldn't get a parts list without the code number from Briggs.

No problem, glad to see my 5 years of experience as owner of a small engine repair was not completely wasted!!

I got a hold of an 8 HP B&S a few years ago that had a scored cylinder. I took it a part and found a casting flaw in the piston, which caused the retainer to fall out and munch the cylinder wall. B&S warranted it no question, even though it was well out of warranty!

Later on, when I opened my shop I had a gent bring in a NOS snowblower he bought from the implement company he worked for. The unit was about twenty years old, but still in the box when he bought it! He ran it about 1/2 hour when the engine died. That engine had the same problem! I contacted B&S warranty department as it was an unusual situation, no problem, warranty starts when the unit is sold, so it was covered! I had a pleasantly surprised customer that day! Greg

LOL!! It has been 16 years since I locked the doors on the repair shop, but somethings I still can dig out of the cobwebs! Actually the older B&S engines like Bud need information for had very few variations over the years. Same block, carb, piston, rod, valves, ............, well, you get the idea! The only tough variations were crankshafts. There are many variations of the PTO end of the crankshafts. Some engines had over 100 different possibilities! The rest of the engine you could mix and match parts to your hearts content. Greg

Yep! the 170400 and 190400 engines were virtually the same. IIRC only the stroke was differant, (maybe it was the bore), so the con rod & crank were differant between series. EVERYTHING else would swap from one to the other. I remember more than once swapping parts to build one good engine from a 7 and 8 HP donor engines. Greg

While I was working for Budgie's Small Engines in CO, our number one warranty claim was simple: self-destructed engines due to lack of lubrication. . . .the purchasers didn't fill the crankcase. Second place went to engines overfilled . . . you can squeeze a quart and a half into a

92000 series if you tilt it ju-u-u-u-st right, but it won't start easily.

I remember back in 76 of a 190000 series on a Snapper rider that came in for a tune up because it was down on power . . .twenty years after purchase. It still had the original points, condenser, and spark plug.

Sand or casting holes seem to be more common now than years ago because the new engine has 4 pinhead size holes in it's bore and Budgie Fazzino said he'd noticed an increase during the 15 years he was in the business.

I just got a reply back from Briggs and the answer was if you don't have the numbers, forget getting a list. . . .actually, it was a link to their site with that message on it saying, politely, that I needed the numbers. They really wouldn't want to know the modifications I've done that engine ... they'd probably say it can't be done.

Thanks again!

Budd

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I was surprised at how much I could lighten the piston (trimmed piston skirt) and how much mass was in the crank's counter weighting.

I made up a dummy weight equal to the rod big end plus half the weight of the small end plus piston & rings and then drilled the counter weights till it would stay in what ever position I placed it on a leveled set of parallels.

Pop the plug and pull this engine thru and it doesn't want to shake from imbalance, but it will spin five or six turns nice and easy. When running, it hardly vibrates, and revs up much faster than I've ever seen before.

I have a 5 HP that I built up for a go-cart. Stock parts for the most part. I polished the rod thinking it may hold together better, used a 3 HP flywheel, (1 inch smaller in diameter, and a pound lighter.), remounted the ignition coil to fit. Advanced the flywheel abut 1/2 the thickness of the keyway and torque the flywheel down with no locating key, removed the nut to be sure it stayed. Set the governor at 6000 RPM, instead of the measly 3600. Milled the head a bunch! I measured the valves height from the top of the block and milled the head so the valve pocket in the head had the same depth, then added a standard head gasket for the valve to head clearance. The only non-B&S parts were the Tillotson carburetor, and the intake manifold I made so the carb would mount inline with the intake port. Kind of a baby tunnel ram! Getting the governor linkage to work was tricky, but I got it.

I put that engine in a small racing frame I picked up. I just ran it as a play cart and it was fun! It would go from zero to 40 MPH in 30-40 feet. You could feel the governor drop of when it hit max speed. I had extra sprockets for top end around 60 MPH but I never did try it with them. No doubt in my mind it would have done it! With the ignition advance, light flywheel, and higher compression you had to hang on when starting it. It would kick back and the starting rope hard enough to do bodily damage! I would warn friends to really hang on when starting an the would just look at me like I was silly, until they gave it a pull! I pulled tendons in my right hand pull starting it once! Took a year to heal from it!

That much timing advance put it near 15-18 degrees BTDC, didn't it? Was that with the Magnetron ignition? Points would have remained at stock timing because of the cut in the crank. I've given some thought to adapting a auto distributor with mechanical advance to my engine, but driving the distributor would be the hard part with the flywheel in the way on one end and the clutches / pulleys, etc on the other.

My first head milling was on a 3 1/2 Hp engine that had a severely warped head. My step-dad had me sand it down with sandpaper on a plate of glass until it was flat. The only head gasket available was a 0.030" dead soft copper gasket hand cut by the local tinker shop. I weighed about 85 pounds at the time and I had to stand on top of the mower deck to hold it down for starting! But boy! Would that thing mow grass, weeds, small trees.

I wanted to use a Mikuni CV carb on my engine but finding a 28 mm version is difficult. On the previous short block, I ran the valve lash at 0.004" and

0.008" and since this engine needs valve work anyway, I'm going to set these at the same specs. It won't help lift much but it adds considerable duration.

Budd

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No points, Magnetron. I had to build a mount for the coil to lower it to the flywheel. I really don't know for sure what the advance was, but it sure ran good! You can buy off set flywheel keys, but I figured I could "wing it". I still have the engine, but sold the cart a few years back. I tried to sell the engine with the cart, but the buyer was looking for a two cycle engine and I just happened to have a reverse rotation West Bend two cycle that would not work on anything except the cart, so he bought it for a few dollars more and I held on the B&S. I think he screwed up! I ran that West Bend on the cart for a while, and the 5 HP B&S was a more powerful engine. Greg

West Bend engines were often finicky, but I never knew they were bigoted and would only work carts.

I think the best thing to happen to two-strokes is the reduction in fuel mix ratios. I put a older Tecumseh 3.5 Hp 2-stroke on a old 4 Hp Evinrude lower unit to build a boat motor once and the 24:1 mix ratio made it so darn smoky when sneaking into a good bass spot I soon went back to rowing.

Budd

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LOL! Well the reverse rotation kinda limited it usefulness! Greg

I'm not so sure about that. Reversed rotation has advantages. One is there would be no need for a reverse gear in a transmission and you'd have as many gears forward as reverse.

Most Cushman singles, for example, rotate clockwise looking at the end of the output shaft, while my Briggs rotates counterclockwise looking at the shaft.

That means the engine rotates opposite the OEM and it creates a whole set of troubles of it's own ... My transmission had to be one that I could input my power into the left side and still run the rear wheel in the right direction; I've got a 1" dia exhaust pipe 4" from a fuel tank under full bodywork; my carburetor is probably sucking engine heat, I had to make a way to disconnect the centrifugal clutch from the trans so it can be shifted.

Now, if only I could get Briggs to build Cushman friendly engines . . .