D8 2U Magneto Timing Procedure

Oldcarman, did you get it running? I wonder if my 7M D7 book has a similar timing procedure? I can scan it if need be.

Hopefully you’re making noise!!

BP.

I ran aD13000 on a pump 10 years I would always put a wire and a plug on the mag and and click it over by hand till the impulse fired on no. 1. Then with the plug out of no. 1 pull it over till all the compression out maybe a little past TDC. And stick the mag on always run worked for me. Hope this helps! 17afarmer

Oldcarman, did you get it running? I wonder if my 7M D7 book has a similar timing procedure? I can scan it if need be.

Hopefully you’re making noise!!

BP.

The mag----- mjk 180? Or mjk 360?

Bruce and others,

Started this pony for the first time since 1986! My 71 year old friend was like a 8 year old with a new bicycle. He owned and ran this thing when he was younger and really wanted to get it going.

It was a balmy 38F (almost short sleeve) weather in Minnesota today. We couldn't pass up the possibility of trying to start this thing (pony only). I figured it couldn't be too complicated to get this mag mounted (MJK 4/2 180B-311 anticlockwise), so I told my friend that we would mount the mag and then sort out based on engine valve positions. The intake valves were both open, and open- all the time...... So we spent a bit of time getting the valves "un stuck". We got them free, put some oil in the cylinders and got pretty good compression.

Then came a bit of head scratching with firing. I knew that these mags produce two sparks per revolution, so how difficult could it be... Once I laid the plugs on the head and began watching valves, we figured out which order the wires needed to be. The 180 degree firing caused a bit of head scratching and then I rotated the mount 180 degrees and we were good on spark for both cylinders. I opened the pipe plug to try to see the timing mark before I started and I do wonder who the heck can get their head in there and see what's going on. Maybe with a bore scope or something, but not with me bending over and looking....

With some gas, we got it to light off with the crank after some coaxing. Wow these things really bark!!

We just ran it for a short while as it had no coolant and we made no attempt to engage the clutch until we get everything squared away with the main. Lots of work in that arena. First thing I'm going to do is fix the mandrel bent tube feeding into the water pump. It was rusted out. I can weld up a tube, but need to find a nice 90 degree tube.

https://youtu.be/-QhHiV1YbVs

2U22558

It was a fun day.

Great work! Keep us updated on your progress. Where abouts in MN are you?

The D8 and DW10 I'm working on are both in Gibbon!

Eddie B,

Thanks much for scanning the books for me. The info seems to be somewhat different than the D8 2U I am working on. I think that the timing mark (from service manual) is via a pipe plug just above the Bosch Mag. I guess I still don't know which is officially #1 and which is #2 cylinder, but it's timed now and was firing well on both cylinders. I don't recall that inspection plate for TDC marks under a cover either. I need to look though.

After digging into this MJK 180 and also deep into a MJK 360 for the DW10 , it seems to me that the Cat service lit seems to talk a lot about the breaker point gap, but the edge gap seems more important. On the MJK 360, I set the points at .014" using a dial test indicator and I could not get the edge gap set even when rotating the breaker plate as much as possible. I re-adjusted the points out to closer to .020" and then I could get the edge gap set to .068-.075 or so. I think that the edge gap is much more important than the point gap. Also, I cringe when I see pictures of an oily feeler gauge going in between two nicely cleaned or new breaker points.

Thanks again Eddie. Ill study the pages and see what I was supposed to do.....

Hi Team,
GREAT job getting the pony running for your friend to see and hear again.

My thoughts--the edge gap helps set the magneto rotor in the optimum spark producing position==most magnetic lines of force cut by the rotor==I usually turn the mag as slow as I can by hand and adjust the edge gap adjustment for the best spark with the least speed--often I find the edge gap measurements are not the best spark generating position.
I usually screw a piece of welding wire to the mag body by one of the distributor cap screws and adjust its end to be around 1/16" to 1/8" from the coil copper connector strip to keep a constant gap--as i zero in on best spark I will usually open the gap to 1/8''
I run my magneto spark plugs with around 0.020" gap to be kind to the coil, cap, etc.
No 1 pony cylinder I believe is the forward cylinder as in the big engine.

I see the side plate on your pony clutch housing for locate the timing line on the case mid way in the forward side of the opening. The MAG line is on the flywheel as indicated but can be hard to find when covered in rust and/or oily clutch dust.
The 17A D7 pony has a top plate on its pony flywheel that via a hole drilled into it a bolt is inserted to match a drilling in the flywheel corresponding to TDC--you have to find the true TDC Firing stroke--compression stroke.
Different models and makes of Magneto have their own individual points gap setting-If the wrong one is used it is well known that the pony will kick back on the second cylinder--especially when starting by hand.
Cheers,
Eddie B.