The Morini Roars!

Another day working on the ‘ped

Finally got the M02 running*!

video: click here

*After week of being solidly confused by the symptoms, and unable to get a clean plug chop (because it wouldn’t run for long enough), I found out why I had no power.  The symptoms were:

  • no power
  • no idle
  • revs up to high rpms, occasionally dies
  • after it ran, it would be hard to start

It looked like I was running rich when I checked my plugs, but it was hard to tell, since I have never seen a working moped plug, and its hard to tell from the pictures online what was is good and what was bad.  I thought that it might have been oil-fouled, and the waiting after the engine ran let the oil drip off the plug- it turns out, I was wrong.

Oil fouling?

The symptoms I described are actually being caused by a vacuum leak.  I think that the cool down was needed so that the metal would shrink and re-seal.  Based on a spraydown with carb cleaner, the leak is between the head and cylinder- so I need to either make or fab a new head gasket.  I have a new stock aluminum gasket on the way, as well as gasket paper…we will see which one gets here first.  When it eventually arrives, it will be time to take the head off the cylinder, maybe sand down the mating surfaces, and then put in the new gasket.

Ghetto Cruise Control (caps lock for my throttle)

The good news for this update is that I also went to harbor freight and picked up some swanky shop towels ($6 for 25!), and most importantly, a set of feeler gauges for setting the timing.  So far I have been using a piece of aluminum flashing that is about .03-.045 mm thick depending on the day, and after adjusting the points with the gauges, it started right up!  I can even start it with one hand, if i work the clutch with the other hand and tie the throttle up with one of those handy new towels.  Which I had to do to get it running for the vacuum test.

Morini Ignition Magneto Rebuild

After installing my new spark plugs and pipe, I discovered that I was no longer getting a spark, probably due to some creative tweaking of the starter coil.  Oops.  So I decided that I might as well replace my points and condenser while it was all taken apart.  This should be useful to anyone rebuilding an M01 or M02 ignition- as far as I know there is not a clear guide on how to do this elsewhere.  It may also be useful if you have another moped, especially so if you have a Dansi ignition.

Get all your parts together on your workbench/cardboard box. Don’t forget snacks!

As you can see, the first step is to acquire a large cardboard box (or if you are lucky and have a table, use that), and put all your parts on it.  The part in the center is the stator plate, which is what the points (in the box with the Italian flag) and the condenser (round thing next to the screw driver) bolt on to.

The condenser should slide right into the stator plate. Mine was an 18 mm wide X 25 mm tall condenser

The first thing to do is to bolt the condenser onto the stator plate.  Not all stators use bolts, some are held in by friction- but this one has a convenient hole that you can bolt down.  The important part is that there is a good connection from the outside of the condenser to chassis ground (which is easy, considering how big the outside of the condenser is).

Here it is, all soldered up.

I skipped a few steps here, but the next thing to do is to screw the points in and attach the coil.  The points have a post that comes out of the bottom, that goes into a hole in the stator plate, and a slot for a screw.  The slot is very important because it allows you to adjust your point gap by changing where and how much the rubbing block engages the flywheel.  The coil is attached by two bolts, and should have only one end that comes out of it (the other goes to chassis ground).  The end that comes out of the coil should be soldered to a wire going to the condenser, and to a wire going to the high tension coil that feeds the spark plug.  Make sure to route all your wires AWAY from the outside of the plate!  Getting your wires chewed up by the flywheel is not cool.  In fact, it is so not cool that the engineers put a little hole in the stator plate, just so your wires can avoid the flywheel.  Clever.

Here it is on the bike. The red wire goes to the ignition.

Here it is on the bike!  The red wire goes through a little hole in the left hand side engine cover, and the flywheel is attached to the crankshaft by the woodruff key.

Now you may be wondering…did it work?  That is still to e determined, because the woodruff key needs to be “adjusted” with a file.

Woodruff Key Removal And Replacement

old key, new key!

A woodruff key is a semi-circular key that is very irritating to remove if it s sheared off, because the slot cut for it is round- you cant just push or pull the key out like you would with a square keyway.  Shearing, of course, something that would happen to a 50 year old moped.  I started noticing wear on the key, and in a flash it was totally gone!  Completely sheared off to the level of the crankshaft, where it is supposed to engage the flywheel to create sparks/power lights.  So of course the solution was to order a new one from treats, who shipped really fast (and is not the company who took forever to ship).

If you look closely, you can see the key that is totally sheared off in the shaft.

Once the key was in my hot little hands,  I was stuck with the task of removing the old key.  This was a daunting task- I don’t know how much abuse the bearings on the crankshaft can take, and the solution to stuck/sheared keys involves a hammer, a punch, and a steady hand.  The trick is to smack one side of the key and use it as a fulcrum to get the semicircle to rotate in its seat.  Once one side is sticking out, the key can be further loosened by smacking it so that it rotates back and forth, until it can be grasped by pliers or vice grips and yanked out.  Unfortunately, the key tends to be small- mine was 2.4 mm across, which meant that beefy punches were out of the question.  You definitely want something beefy like a center punch for this, because a pin punch of such a small diameter will bend.

After some judicious smacking, the key came loose

Once mine got a little looser, I  managed to grip it with pliers and pull it out.  It was surprisingly not that hard.  The last step was to install the new key in the slot.  True to form (for this project) it was a little small in the width department, and a little tall in the height department, so some loctite and filing may be in order.  Despite that, the new key is pretty good as far as rotating the piston/chain/magneto so I am optimistic that this will solve my no-spark issues.

Happily installed in the flywheel.

More Morini Repairs.

Old pipe has a nice bend so i have more clearance, new pipe is not full of carbon. Maybe the old one will make a comeback someday.

Since I knew the old pipe on my morini M02 was clogged, and also restricted, and since there was a large moped parts sale, I decided it would be a good idea to pick up a new one.  I took advantage of the sale to also pick up some carb parts.  My carb wasn’t really “broke”…but was certainly leaking.  This was no fault of the 50-year old dellorto (sha 14-12, for those who are curious), but the gas line that I installed turned out to be a smidge too big to really clamp down on the fuel banjo, not to mention that the in-line filter behind the banjo was probably clogged as well.

As you can see, the new gasket doesn’t fit the old exhaust header. Or the new header, for that matter. The holes are too far apart.

So, after some shipping snafus on the part of the supplier, my parts arrived about three weeks after I ordered them.  Grr.  And, true to this being a project bike, they didn’t fit!

Thank goodness for tools. I had to take about .5 cm off the whole outside of the exhaust header.

The exhaust header, for the metrakit MKIII exhaust was waaay too big.  I think the cooling fins on the engine block might taper, so it is possible they just took a bad measurement and produced a bunch of exhausts that don’t fit.  I guess I will just have to expect a lot of filing and fitting in the future.

The mounting bracket needed to be enlarged. Lots of filing was required to do this.

After a lot of filing, I managed to get the exhaust to hang onto the bolt that used to have the center stand spring attached to it.  I don’t know what the final solution to the problem will be, but it may end up being some kind of hack-and-weld job that attaches the new expansion chamber to a better-angled pipe.

I also picked up some B6ES plugs from the un-named supplier, because of some advice I got from moped army, where someone pointed out that I had the wrong plugs.  oops!

Good thing someone caught that.  ES stands for “Extended”, and the extended plug is in fact, quite a bit longer than the regular plug.  In a 50 CC engine, this is kind of a big deal!  My estimate is that they were maybe 3CC larger.  If you take the original compression ratio of 7.5:1, that means that the compression with the HS plugs was roughly 6:1- which would dramatically decrease power.