Back up and running


Last weekend I fired up the Guzzi for the first time since August 10.  It runs like  champ!  I am still fiddling with the power commander tuning and a few irritating habits it picked up while it was down.  The most annoying is that the shifter doesn’t return to center on an upshift.  If I tap it with my toe it will re-center and work fine, but it makes upshifts really slow.  I have played with the linkage to make sure it isn;t binding.  Next I will have to pull the shifter off the transmission and look inside.

The less irritating one is that the tachometer has gone crazy.  First I had to reset the calibration because it was barely reading anything when I first started.  Somehow the pulse to revolution had gotten set to 2.0 rather than 0.5.  Then even stranger is that under certain very repeatable conditions the tach spikes.  It only happens with full throttle and the engine able to rev up quickly under load.  It won’t do it in neutral from idle, it won’t do it if I use the rear brake against the acceleration and just hold full throttle.  I have two theories, first, I enabled the power commanders acceleration pump feature.  This acts like a carburetor acceleration pump when the throttle if opened quickly.  The accelerator pump wasn’t in the PC the last time I used it so since it si new, and should be responsive to the same conditions that come with the problem I am betting there.  The second theory is a ground problem somewhere.  Given the repeatable nature of the problem the grounding issue may be only a contributor, but grounds should’t care about throttle position.


Reality Bites


I have been stalled on the RD-400 while I try to solve the rear suspension spacer problem.  My solution is to get a lathe.  I have been saving and searching for a while with no real luck.  Then, last week disaster struck the Guzzi.

The MG V11 have an internal oil filter.  Normally I put a hose clamp around the oil filter as an insurance against it backing off while the engine is running.  Last time I didn’t.  I also didn’t notice that the oil pressure idiot light wasn’t working.  Combine those two last week and I roasted the engine.  It’s ugly.

The rods are not salvagable.  I had to remove one of them with a cutoff wheel because it got so hot the rod bolt welded.

Here is the crankshaft:IMG_1176

This is an excellent picture of a really bad rod journal:IMG_1177

Scored main bearing:IMG_1178

And its matching partner:IMG_1179

And here is where most of the bearing material went:IMG_1180

Fixing this will drain my lathe account…

Let the frustration begin, again.


What’s next

My next project will be a cafe racer based on a 1976 Yamaha RD-400.

I found a basket case (literally, it came in baskets!) RD400 on eBay.  I have wnated to do something like this for a long time: a tiny, light cafe.  I have never had a two-stroke and the RDs had great reputations.  I have always wanted an RZ350 but those are getting collectible and I don’t do that…

RD400 01.jpg

Fantasy garage

The initial set of parts did not include wheels or a swing arm.  This was good, it made it easier to decide to go all out and make this really different.  I started off with a few ground rules: I wanted modern tires, but not enormous tires the bike couldn’t deal with and I wanted to keep the suspension geometry as close to “as designed” as I could. I will also not take short cuts on this build.  I have no deadlines and will take my time and do what I want here

The original RD400 came with 18″ wheels which are evidently enormously heavy and very narrow.  18″ tires are getting hard to find so I set about looking for a set of 17″ wheels that could take the sorts of tires I wanted.  I am targeting 110/70R17 and 150/60R17.  Both of these sizes are easy to find with modern radial construction.

Ninja 250’s were my first bet.  It is a light low powered bike built continuously sine the 80s.  But as it turned out until very recently (2008) it had 16″ wheels.  That left only very recent bikes and finding wheels was difficult.  I started looking at early 90’s sport bikes and found the the CBR600 F2 had the size tires I was targeting.  And wheels were pretty easy to come by.  There are other bikes that could lend their wheels, FZ400s wheels are popular swaps, but

I don’t really like the three spoke designs so common today.  The CBR wheels are six spoke and look good (they will not be yellow when I am through!).


Researching the RD400 on various forums indicated that late 2000’s GSXR-600 forks were a good fit to move up from the spindly little forks the bike came with, and they are pretty cheap to come by as well.  The All Balls Racing website has an excellent search function for doing fork swaps.  They showed that to put these forks on the RD400 frame I would need 30mmx48mm Roller Bearings.

So, here I had an RD400 frame, CBR600F2 wheels on the way and GSX-R600 forks.  Now I could sit and wait for the part to arrive.  And the bike is taking shape in my mind and perfection is mine for the taking!

Reality Garage


Mixing and matching parts from various manufacturers is not for the faint of heart.  For example, the GSXR forks are set up for 310mm rotors, but the CBR600 wheels are 298.  The bolt pattern for the wheels is 6x166mm which is very unusual.  I found a parts list for EBC brakes that showed the modern Triumph Thruxton had the same rotor bolt pattern so I order some of those rotors.

Front wheel bearings

My research show the CBR wheels use 47mm bearings with a 20mm axle.  The GSXR forks are set up for a 25mm axle so i bet on the come and ordered so 25mmx47mm bearings. And here was my first dose of reality:  The CBR wheels actually had 42mm bearings.  OK, that isn’t tragic and I found some bearings that should do the trick, they won’t last 50,000 miles but they should do.  Of course I had to order them.

Fork Swap

The bearing from All Balls Racing showed up and worked quite well, except that I mis-measured the length of the fork stem and pressed the lower bearing in without any spacers.  I almost had the new back bearing back off when my tool slipped and irreparably damaged the race.  So I cut that one off and pressed in the other new one on with spacers to make up for the longer stem and ordered yet another bearing from All Balls.

Sprocket Trouble on the Horizon

For giggles I put the CBR rear wheel in place in the RD frame with the wheel centered. It looks very much like I am going to have to play serious games with the sprocket carrier to get the chain to clear the frame.  Oh, and if I wanted anything like the original wheel base I will have to build my own swingarm.  Well, I am doing this for the challenge.

So begins another project where it will likely be 2 steps forward and one step back for a long, long time.

Today’s scorecard:

Fitting Thruxton rotors to the CBR front wheel Win Research worked, rotors fit perfectly and the rotor bolts even fit.
Fitting the GSX-R forks to the RD Frame Tie Will ultimately work, but I lost style points for mis-measuring and destroying a brand new bearing
Fitting the CBR wheel to the GSXR fork In play Found bad data and ordered the wrong bearings, but there is plenty of room in the wheel for the bigger axle once the correct bearings arrive.

V11 Sport with Laverda Fairing


IMG_0972 IMG_0978 IMG_0977 IMG_0976 IMG_0975 IMG_0974 IMG_0973

The M3 Today




























Preparing to build Space Derby Kits


The Space Derby is just around the corner.  If you would like to build the kits during your meetings with the kids, there are a few things you can do to make it much smoother and more enjoyable for everyone.  These are tasks that either take too long, or are too difficult for the little kids to do.

Preparing the Bodies

The first thing to do is to join the two halves of the body together. This is very simple, but the glue can take a while to dry enough for the kids to start in with shaping the bodies. Use a thin coat of any wood glue (Elmer’s school glue is fine) and put the two halves together. Make sure the holes on each end are the same size. You will have something like this:

Once the body is dried you need to cut notches in the back of the body so the rubber band has something to grip. Look at the body, and on the end with the LARGER hole cut two notches as in this video:

Building the Propeller Assemblies

Now you need to assemble the propellers. This is a bit fiddly, and requires more strength and coordination than the younger are likely to have. First you need to adjust the propeller shaft. As it comes from the Scout the opening is too small to get the rubber bands in:

Use needle nosed pliers to open up the end so the rubber band can go in easily:

The rest is pretty straightforward, but difficult to explain in words, so here is a short video:

The rest of the instructions are pretty good and the kids should be able to do the rest pretty quickly.

The M3


This has been my current project since last August.  Lots of electrical reconditioning, soon I will get to the driveline.  Garden variety Cosmos Black 95 M3.  First year of the finest M3s made!