JD 1.5 HP Mag gasket

[Griff]

I have the new donut felt gasket for the mag. Does it go inside or outside the crankcase? Or soaked in oil and stuffed around the mag shaft from the outside?

[Tom Werner]

Griff, I didn' use it. It does belong between the mag body and the steel plate on the side of the crank cover. It was used to capture the oil that would sneak out since there is not a mechanical seal.. periodically, you would remove it, wring it out, rinse, and replace.. I cut a strip of paper shop towel approx. 3" long and rolled it up to 1/2" dia. and pushed it between the bottom of the mag body and the steel plate. Before the accumulated oil got messy, I would replace it.. Tom W. in WI

[Griff]

Thanks, that explains a lot! Hmm, sure seems like this would be a natural crankcase vent. I'm getting excited as it's close to coming together.

[Colt Edin]

Hey,

Just so happens that I assembled one of these JD 1.5 HP engines last night!

I didn't bother taking the gear off of the mag to slip in the new felt, I just assembled it, (cut a slit in the gasket that goes on the plate between the mag and the gear and gooped it to the plate) cut the felt, pulled it through under the mag drive, and stuffed it in there. There wasn't much room! I've ran the engine for a while now and the felt stayed put.

How much compression did yours have when you first started it up? My engine has some... about as much as when the old rings were in it. I lapped the valves, too. I'll let it run for a few hours today so that the new rings can seat.

-Colt

[Griff]

I haven't been able to do much, my well pump went out. But I have hardly any compression, and before I put the "lid" on the crankcase I want to pull the head again and see if the valves are right. I assumed the machine shop, when they reamed the guides for the new valves, faced off the seats too. I've also gotta re-read the instructions for timing the mag. I've got the marks lined up on the gears just like they came apart but that sure don't line up with the instructions to push that little button on the right to feel the indent. Still having fun though (when I get water again).

[Griff]

IT RUNS!! I won't be doing anything with my right arm for a few days though. It seems as though the mixture adjustment is much more critical now than before, with the new valves and piston. I could always get it to pop once or twice but when the mixture was right it starts now with one or two revolutions.
.
Question - Is it normal to get a hint of flame out the exhaust and a small puff of vapor out the air intake when it fires? Or do I need to play with the ignitor trip lever some more. It's set right by the book, just as the mark on the flywheel is level with the trip rod. It sure runs nice though and it would never have happened without all the help from here. And best of all, no more smoke cloud and oil "spray" out the exhaust.

[Craig A]

NOTHING is "normal" for a John Deere engine!!! Except for oil running out of every pore and I can talk like this because I have owned 3 of them. If it's puking gas out of the mixer you might TRY adding a little tension to the intake valve spring-----this is ASSUMING you ground the valves though. Pay SPECIAL attention to at what point the exhaust valve CLOSES. This is also VERY important.
When running slowly does it run with the choke plate wide open? That's another big unknown--it varies from engine to engine...some will...some won't.
About the most NORMAL thing for them is they bring a lot of money....
Craig

[Griff]

No no, it's not "puking" gas, just a hint of vapor when it fires. My wife says I'm watching "Monk" on cable too much, too much of a perfectionist. It runs so slow I just about turned off the governor nut and still without a choke! I did put on a little heavier intake spring though. I think I'll get a stopwatch and see if I can count the rpms.
.
BTW, talking about oil leaks.... (and I don't see any yet after 1/2 hour or so of running) I have a friend who hooked up a vacuum cleaner to the oil filler hole of his Model T Ford after he rebuilt the engine, and while the vacuum was running, ran a tiny bead of silicone around all the gasket lines. He may have one of the few "T's" around that don't leak! Think I'll try it on the JD if I see a leak but hey, that's part of the fun ain't it? (Wiping off the oil.)

[BobRR]

They dont rust that way! I did notice on mine if I run it real slow the mains seem to run hot? BobRR

[Craig A]

Originally Posted by BobRR

They dont rust that way! I did notice on mine if I run it real slow the mains seem to run hot? BobRR

You must be running it REALLY slow!!! Well, as the only splash lubrication is generated by the governor weights I suppose oil WOULDN'T make it to the mains--or very little anyway.....
I had one JD 1 1/2 I could start just by flipping the flywheels--NOT using the knuckle skinner starting handle. It seldom, if you're starting a skid mounted one on a concrete floor, when IT hits the first time your knuckles are gonna get shined up on the floor........... I HATE when that happens!

[Chuck Moss]

One the flames coming out from the exhaust, I find that my 3HP JD E will do that if the mixture is leaned out too much. There is a just right spot (about a 1/4 turn open) that is just lean enough to not make visible smoke (well, almost none) and just rich enough to not make the flame. Flame really shows up more in the dark!

Lean mixtures burn more slowly than "correct" mixtures.

On knuckle skinning, I keep one glove (right hand) with engine all the time. Haven't worn a hole through it yet, but the time will come.

Chuck