Ivy: Motor Swap Day

Had a clear Sat afternoon to work on swapping the motor from the old original Viola to the new Monkey Motor.

Surprisingly painless.  After removing exhaust, pegs and kicker pedal, simply dropped the old one out.

Noticed that the rear screw on the ignition coil was almost all the way out!!  Note to self: use lock washer and/or loctite on those screws.

Removed the tank and laid her down and mounted the new motor after running the coil wire through the frame.  No problem with fitment.

Next, test for spark and then for oil leaks.

Run Red Run: Engine Install

After all the back and forth around possibly installing the motor to Astrid or Evie first as a test, decided to just cut to the chase and mounted the motor straight to Red.

First things first, swapped out the smaller bullet on the coil for the bigger red one.

Install itself was relatively painless, though the trick is that you have to set the rear in place before the front.  Had the coil wired up through the battery box and just made sure to pull up the slack as I slowly pushed the engine into place.

Added the top end and the exhaust.  Added the step bar so I could ride the sidewalk a few times, but really need to add the pedals to get a good feel for the ergonomics.

Run Red Run: Engine Mount

Wanted to get the new "Double Bill" engine mounted so that I could get VIN verification done with officer Wong.

Found that the new stool stand with the metal brackets fits perfectly under the Early engine.  Popped out easily.

The laid the bike down on her right side to install the new one.  But while the front mount slid right in, the rear of the engine would just not slide through.

After a few attempts at just muscling it in, decided to check measurements.  Found that the corner engine mount was about 1mm wider than the early engine (which slid in nicely).

Decided to file down the sides of the mount by that 1mm instead of messing with the frame.  The big file made short work of that soft metal.

Once it was file down, it still took a little elbow grease to line up, but got all the bolts in relatively easily.

With the the engine mounted, the next test was to mount pegs and pedals.  The right side (kick and rear brake) seemed fine.

But the left side was a little odd.  The shift pedal and the peg bar were on a perfect horizontal line, which felt uncomfortable because there was nowhere to rest your foot without touching the pedal.  But then again, now I wonder if that's closer to stock then the way Roxy and Ivy are setup - with the bar up so much higher than the pedal (because in that setup, you can't really engage the pedal with your heel).

But the peg itself also seems a little bent forward so it's probably lower than it should be.  Also the shift pedal is aftermarket and didn't seem to want to push all the way flush against the shift shaft.

Need to get a stock shifter... and maybe test Roxy's pegs and then keep an eye out for a similar peg on eBay.

Bottom End Build: Busy Sunday

Lot of good work today on the carpet (and in the kitchen).

New toy is an infrared thermometer.  Combine that with the heat gun and use it to heat up the case to install the bearing.  All sounded good in theory, but wasn't sure it would work in reality.  But actually everything went perfectly to plan.

Heated the case with one hand while taking the temperature with the other.  Heated it up to about 215 and it didn't take very long at all.  Did this on top of the stove (on a baking sheet covered with tin foil).  Meanwhile had the 6004 bearing in the freezer.

As soon as it hit 215, I moved the case down to the floor (on top of plywood) and knocked the bearing into place with a 29mm socket with just a couple taps of the dead blow hammer.

Almost too easy, but job done.

Thought about removing the old bearing on the other side and installing the new one, but realized that I didn't have a socket big enough to safely knock the bigger 6204 bearing into place.  Need to get about a 32mm socket or maybe a dowel of equivalent size.


Brought up the crankcase for inspection.  This is the one with holes in it.  Don't know why it never occurred to me before, but now I assume that the holes are a custom mod, not a different type of stock crank.  Did the inspection as per Clymer's and it was all well within the wear limits. 

Broke out the Tusk tools and installed the crank easily.  Actually got the entire case all the way back together but then had second thoughts.  Not really sure what the effect of the drilled flywheels will be on a stock setup and may not be worth the risk.

Thought about pulling the crank from the model engine and swapping it with the custom one, but honestly just too much work!


Ended by swapping our the rusted cable arm on the clutch cover with the one from the model engine.  Learned something new: there's a little clip on the arm that holds it in place.  Easy to miss if you don't know it's supposed to be there.

Bottom End Build: New Parts

First batch of new parts from eBay/Amazon, including:

• Nachi 6004 bearing
• 6204 bearing that I thought was Nachi but was generic (no wonder the price)
• complete kickstart
• rotor
• alternator
• clutch cover (with the cable guide rusted solid)
• cam chain

Installed the kickstart and alternator on the carpet, no issues.

Bottom End Build: Carpet Garage

Brought up the bottom end up to start working on it in earnest.  Just getting my head back into the disassembly.  All I've got for now are the cases, the tranny and the shifter.

Run Ivy Run: The Sound of Catastrophic failure

Session actually started off very well.  I installed the stock air filter along with the S90B carb.  Everything went together very nicely.  This is the newish airbox, plus one good cover from the Viola original, plus a new repro air filter for 4-into-1.  Also confirmed the needle is in the middle position.

Before starting the next job of replacing the rear sprocket, I figured I'd torque the head bolts - a little job that just needed doing.

I use a 14mm socket on the torque wrench since they are 8mm bolts and start cranking away.  I'm then surprised to find that the socket starts slipping on the bolts when they get tight.  This strikes me as odd, but I don't actually PAUSE to ASSESS the SITUATION.

If I had, I would have seen that the bolts are in fact 13mm and not 14 like they usually are.  I was stripping them.

As I was tightening down the top left side bolt, there was a sudden CRACK and the wrench came off suddenly.  Apparently, I'd torqued the bolt enough that it ripped the bottom end rod in half.  Well, that's just great...

Though, if that rod was going to fail on torque, then it was always going to fail.  There's no way I could have under-torqued the bolts, somehow expecting the rod was weak.

Though I'm still not sure if the slipping socket had anything to do with it.  Did the slippage cause the wrench not to read the torque correctly which meant I was over-tightening?  I don't think so... but...

So definitely a major issue.  I think it's going to be a nightmare trying to remove the broken rod and replace it.  But I figure the engine should run with only 3 of 4 connecting rods???  Well, at least it that can't affect start up, can it?


After the shock of that wore off, I did the rear sprocket.  Pleased to find that in general, all the steps came back easily.  The job actually took a lot less time than I'd thought it would.