I reused the original base gaskets when I put the motor back together, so I didn’t check the squish, but I’m thinking I should have. Alan also suggested she could be running too lean or the timing is too advanced. Easy things first, I got out the timing light and checked both cylinders. She’s right on the mark in both cases, so it’s not the timing.

The guys on the Duc list tell me it’s fairly common to retard the timing 2 or 3 degrees after installing high compression pistons. So I’m going to try that next. The problem is moving the pickups a few degrees will affect both the high RPM advance and the idle advance. With the idle advance reduced, the bike will be harder to start, and she’s already hard to start, so I don’t like that plan. A cheap alternative is to file a few degrees of the trigger “lump” off the flywheel, as described by Brad Black. That will allow me to leave the idle advance alone while reducing the high RPM advance, but once you file off that material, there’s no going back without a replacement flywheel. A third alternative is spending a bit on an Ignitech TCIP4 box. This gizmo allows you to connect a laptop and set the ignition advance wherever you like for any RPM. This sounds wonderful in theory, but I found a Monster forum thread with lots of complaints about the box failing and Ignitech taking no responsibility. CA Cycleworks has stopped selling them for that reason.

And regardless of whether tweaking the timing fixes the detonation, I think I really should retune the carbs. Between the open airbox lid, the spaghetti exhaust, and the high-comp pistons, surely the fuel metering is a bit off by now.

I bought my 41mm FCRs from the great Chris Kelley, who dialed them in before sending them out. Way back when Brett and I installed them (along with the Staintune Spaghetti exhaust) we bolted them in and didn’t need to fiddle with a thing. That said, I’ve always wondered if she’s running a bit too lean. I’m getting 58 MPG which seems, frankly, absurd for the amount of fun this bike provides. The Ninja 250 (making all of 29 ponies) “only” gets 12 MPG better mileage.

Alan suggested pulling the plugs and looking at them. These NGK D8EA plugs have all of 8 miles on them right now, so they may not be diagnostic yet, but here they are from two angles. The vertical cylinder’s plug is on the left in both photos, and the horizontal’s plug is on the right.

So maybe Buttercup is running a bit lean and the Seafoam isn’t helping matters? Fortunately, Chris Kelley did a fantastic write up several years ago on diddling with the FCRs. So the next step is to go through the carbs and verify that everything is where Chris said it should be. And if so, I’ll experiment with enrichening it a bit. Here are his settings:

Base settings:
Fuel screw (mixture screw) 3/4 turn (checked)
Slow Air Screw 1-1/2 turns
Float height 9mm
Main Jet 155
Main Air Jet 200
Slow Jet 60
Needle EMT
Needle Clip 3rd from top

Now that those settings are double-checked, it’s time to start tinkering. But before I get in there and just make adjustments willy nilly, I called the master himself. I told Chris that Buttercup has an open airbox lid with a flat K&N filter, FCRs with settings unchanged since he sent them to me, 92mm JE pistons with 11.5:1 compression, and a full Staintune spaghetti exhaust with the baffles removed from the can outlets. Chris suggested I quite simply add another 1/4 turn to the fuel mixture screw. Really? That’s all? I was skeptical, but there’s no question Chris knows this stuff, and you can make this adjustment without doing anything more invasive than removing the body work from one side.

So I got in there, turned the screws on both carbs fully in, and then backed them both out 1 turn. The engine was cold, and my normal method for starting her involves 2 or three pumps on the throttle grip and then pressing the starter and hold it until she lights (usually 3 or 4 seconds). At this point in my routine, it’s repeat as necessary, and it’s always necessary. But now….. two pumps and stab the starter once and boom boom boom she idles just like that. What the? Really?

So I put the bodywork back on and took her for a spin. No off-idle stumble, no backfiring at steady throttle, no constantly revving her to keep the fire lit until she warms up, no RPM “hanging” when the throttle is released, and though she still pops a bit on deceleration it’s nothing like it was before. Well, blow me down.

I’m still pinging (though very little now) on hard acceleration though, so next it’s time for Brad Black’s flywheel modification. I bought a used, stock flywheel on eBay and I’m going to take 2 degrees off the leading edge of the trigger lump. My measurements indicate the flywheel’s diameter is exactly 150mm. The formula for calculating the length of an arc is 2πr(C/360) where C is the central angle in degrees. This works out to 1.31mm of arc length per degree, or 2.62mm for 2 degrees. I’ll never be that accurate in my wildest dreams with a file, so I’m shooting for 2.5mm.

UPDATE: High compression pistons installed, engine covers painted, new clutch plates, new pressure plate, new clutch basket, heads painted, valves lapped, shims adjusted…

2/20/2012 UPDATE: The front wheel is mounted and the engine is back in the frame. Progress!

UPDATE 2/21/2012: Now with wheels!

UPDATE: 2/23/2012: Yesterday I got the electrics connected and zip tied. I also cleaned the 11-month-old gas out of the tank and replaced the fuel filter. The tank’s filler gizmo was soda blasted. I thought about painting it but after doing some research I don’t have moch confidence that any rattle-can paint is going to be fuel resistant. Maybe I’ll have it anodized sometime.

Today I put the tank back together and installed the spaghetti exhaust. Then it was time for the moment of truth! I poured in about a gallon of premium and cranked her over for a while with the kill switch off to get some oil into the heads. Would she start? Better have a nervous cigarette and try to think of anything I missed. Puff puff puff, can’t think of anything, so it’s time to give it a go. After some cranking to get the fuel into the carbs again….putt putt whir putt putt whir putt putt PUTT! rumble putt putt rumble rumble putt vroooooooooom! She’s running!

UPDATE: 2/24/2012: Today I finished up a few minor details. New brake and clutch fluid. Throttle cables lubed. Bodywork installed. Tomorrow she’ll be ready for a break in ride for the engine and brake rotors.

The stock clutch basket weighs 2.452 lbs. I wiped off the clutch residue before weighing it.  The Barnett basket going on weighs 0.992 lbs.

The stock clutch plates (which are well worn) weigh 3.104 lbs., and the replacement Barnett pack (with all its friction material intact) weighs 2.016 lbs.  The stock clutch springs, caps, and screws weigh 0.336 lbs.  The Speedymoto springs/caps/screws weigh 0.288 lbs.

Those are the only bits I’m actually replacing at the moment.  The total for the stock components is 5.892 lbs., and the replacement bits weigh 3.296 lbs.  That’s a 2.596 lb. savings, or about half the weight of the stock components.

I found some old wiring up there (the kind connected to ceramic insulators) which is no longer connected to any circuits in the house. So I decided to remove it. Then things got interesting. Actually, that’s too charitable; things got fucking annoying.

The city’s building inspector showed up to look over my roof after I did the tear off. He informed me that A) I was supposed to get a demolition permit to take up the deck slats, and B) I needed a permit to remove the old wiring even if it wasn’t connected to a damn thing, and C) I needed to either repair or replace the parapet on the west side of the house, and D) I needed a permit to install insulation, and E) I have to use 90 lb. CRRC-1 rated asphalt for the top layer of the roof. He said he’d call the girls in the office and get them to amend the permit for the demolition and the insulation.

Fine. Whatever. Talia went down to the permit office a few hours later. She was told the old permit could not be amended, but we had to get a whole new permit for the insulation and wiring removal. Oh, it that would cost $195. Just so we’re clear, this permit is for removing some wiring that isn’t connected to anything, and it’s perfectly legal to just leave it there, and to install $240 worth of insulation. It’s extortion to apply essentially an 81% tax on installing insulation.

So I cut the parapet off the back of the house, removed all the old wiring, and reinforced some rafters I thought were weak from dry rot/termites/age. Before I even think about putting in the insulation I have to call the city and have the inspector come back out to make sure I really did cut out all those old wires. So I called. Here it is 5pm the next day and I’m still waiting for the guy to come peek over the side and say, “yep, you sure did cut off those wires.” I’ve accomplished nothing at all today waiting for the inspector who never came.

The next step is to put in the insulation and then wait for the inspector to show up again and see that yeah, I really did put in some insulation. Then I get to put on my decking and have the guy come back once more to see that I used the right number of nails. Then, I’ll finally get to put on my roofing felt and asphalt. Oh, and by the way, there is no requirement for the Cool Roof Rating Council, 90 lb., high reflectivity, high emissivity, asphalt. That’s for non-residential buildings only. If I’m lucky, I’ll get a roof back on my house by Christmas.

UPDATE: Talia called the building department this morning and left another message on their machine asking them to please come out and see that we really did cut off some wires. She then called a different number and managed to talk to some girl who said they needed 24 hours notice to schedule an inspection. Apparently they’ll now come “sometime this afternoon.” Today is Wednesday, which is about 48 hours since I called them on Monday.

UPDATE: The inspector showed up and said my wiring removal was fine. He told me I could put in the insulation and take a few photos for him instead of waiting for him to come back before installing the decking. So I put in the bulk of the insulation that day.

The next day I finished up the insulation and got to work on the decking. About this time Alan came home and announced that he was off work for the rest of the day since it was going to rain that night and he’d have to do the night shift, so he offered to help me out until about noon. I was in a big rush to get something on the roof before the rain came, so this was some welcome help.

Talia has a vendor at her shop, Mike Adams, who makes wonderful things out of exotic woods. He’s always looking for some extra cash, so she asked him to come over and help with the decking. Alan and I got into a good grove getting the decking down when my framing nailer jammed. I cleared it and it jammed again. And again. And again. Urgh. Alan and I were discussing alternatives when Mike arrived. I sent Alan off to bed so he could rest up for his night shift and Mike and I went to Lowes to get a new nail gun and some lunch. With that problem taken care of Mike and I got back to laying decking. Mike was amazingly fast at cutting the plywood and getting it in place. I barely had time to finish up nailing a sheet when he had a new one in place for me. He stayed long enough to help me get the roof covered in blue tarps before the rain came, so we were snug as a bug in a rug all night. The rain came and came and came, but we stayed dry.

Progress now crawled to a snail’s pace. Vacation was over, so I had only about an hour of daylight in the evening after I got off work to do the roof. And it’s rained nearly every weekend, so I’ve hardly done anything. I ripped a bunch of 2×4s to use as cant strips and got the base layer on over the next week or so.

See that bump in the middle of the roof? That used to be a whirlybird. At some point not too long ago some poor sap was living in the garage. They sheet rocked it (poorly), insulated it, and sealed up the garage door. The first thing I did when I moved in was pull all that crap out and fix the garage door. The whirlybird was an exercise in laziness. They pulled the whirly cap but left the base since it had several layers of asphalt over it.

They hammered it flat as best they could (which was not very well), and then built up some crap (extra asphalt, some swollen chip board, and a few pieces of cement board) around it. As a result, when it rains, water pools in this area. Can you guess where the garage roof leaks? Yeah, good work, guys.

With that layer of asphalt and felt off we’re down to the original roof.

Only two layers of felt to go!

Out comes the whirlybird base. They were not shy with the nails on this thing.

All the sheathing exposed.

UPDATE: Dodging the rain has only allowed me to work on the roof in fits and starts. Eventually I found a Saturday with no rain and I tore up all the slatting and put down new decking. I wasn’t too sure if I really needed (or wanted) to pull up the garage decking, but I’m glad I did. The area at the back of the garage where the worst leaks were had some serious dry rot. The boards back there came up with almost no effort. Now all that’s gone, and with the new decking, felt, base layer, and a big blue tarp the garage had finally been dry in the rain for the first time since we bought the house.

Over the following week, one hour a night if it wasn’t raining, I installed cant strips and a layer of 30 lb. felt. Then I put a layer of Tarco EasyBase on top of that. The base stuff is pretty snazzy. You lay it down and cut it to size. Then you peel off a layer of plastic on the bottom to expose the semi-sticky surface and press it down. It doesn’t seem to stick too well at first, but once the sun warms it up this stuff is fairly permanent. But it’s not cheap. I spent over $2100 on the base layer, the cap layer, and some 6″ aluminum flashing for the tops of the parapets for the house and garage. Today is Thanksgiving and it hasn’t rained yet, but it’s supposed to. The remaining 3 days of the “weekend” are supposed to be warm and dry, so hopefully I’ll be able finish both roofs this weekend.

By the way, have I mentioned lately that I love my truck? I was able to slide 35 sheets of 5/8″ plywood into the back of that beast and still close the tailgate. And 20 rolls of insulation went on top of that. Yowza!

UPDATE: 25 November. Today I’m making lots of noise and dust, burning up masonry blades (and probably 2 different circular saws) modifying the parapet so that it’s 5 3/4″ wide. The 6″ aluminum parapet cap won’t fit at the current width, which varies wildly from 5 1/2″ to about 7″.

My personal stand is made out of about $10 in angle iron, a piece of threaded rod, and 2 bolts. It’s short enough to be bolted on while the bike is on the lift, so it doubles as a frame stand if you’re removing the suspension.

Here’s Joe’s stand (and his materials list), which is much more robust:

You are basically building 2-U’s for the mount legs.The front legs are the longer ones. The rear are the 5.5″legs.You need 13.5″ between the inside of the angles to sit on the jack lift legs. Cut the pieces and tack as you assemble.It is easy to see how it goes to together.Use the picture from the orig.for reference.

2- 1.5″ X 11″angle (sit on jack pads) 90 to base legs

2- 1″ sq. X 18″ (horiz. base pieces)

1-1″sq.X 8″ (left frnt) welded to top of base leg
(both end up 8″s in length)
1- 1″sq.x 9″ (rt. frnt) welded to outside rt base leg

2 - 1″sq. x 5 .5 ” (rear vert. legs) mounted directly on top of base leg ends

rear mounts 1/4″ or 3/16″ flat stock
2- 1.5 x 2.5″ 10mm or 3/8s hole drilled .5″ center from fwd edge.

Weld angle 2″ in on bottom of base leg. (Rear)
weld angle 2″in on bottom of base leg (frnt)
Angle overhangs 1.0″on each outer edge of base leg.

You want 6.5 ” between inside base legs. (8.5″ outside to outside edge of base legs)

Rear mounts get (flat stock pieces get welded flush to outside top 5.5 rear verticals)

Front verticals get drilled 3/8ths hole centered .5″from top of vertical legs.

Hardware 2- 10mm x1.50×100mm bolts.( frnt mounts)

1 - 10mm x 18″ steel rod or drill rod for back crankcase holes

Lastly, here’s George’s upright floor stand. It’s a Harbor Freight engine stand with about $20 of 4″ aluminum angle, cut to shape for a Bevelhead.

Bicarbonate of soda is hydrophilic. The stuff will soak up humidity and when it does it clogs the blasting gun until it dries out again. When it’s done drying, it’ll be in hardish clump that will need to be broken up. I’m running the blasting gun at about 90 psi, which means my little 13-gallon Campbell-Hausfeld compressor was running all the time when I was blasting. Compressing air generates a lot of heat (Boyle’s Law), and hot air can absorb more moisture than cold air. When the compressor cycles every now and then the compressor tank and lines remain cold and the moisture can condense on the tank wall and make its way to the drain. But when the compressor runs all the time it eventually gets hot all over, leaving no where for the moisture to condense.

The first fix for this problem was an increase in compressor tank capacity. I found a used, 33-gallon, Craftsman compressor on Craigslist for $75. I’m now running both compressors in parallel, so I’ve essentially got a 46 gallon capacity and two compressor motors. With the two compressors’ regulators set to the exact same pressure they cycle on and off independently: sometimes neither run, sometimes one or the other, and sometimes both. This means each tank gets a chance to cool a bit between cycles, so the moisture can condense.

My second fix was to run a bunch of copper piping from the compressors to the blasting cabinet. Copper is great at conducting heat (which is why they put it on the bottoms of high-end cookware) so the copper lines allow another path for heat to escape the system, which means more moisture condensation in the lines. I ran the lines with a slight down slope (some Googling suggested a 1″ drop for each 10′ of line) so the condensation can be pulled by gravity to the low point. Now for the real trick: at the lowest point I installed a T for a drip leg. Condensed water collects there and runs into a nifty moisture filter I bought from McMaster-Carr. This little gizmo is basically a 3 oz. bowl for water to collect, and it has a float that opens a valve in the bottom whenever the bowl fills, blowing out the collected water like a delightfully wet fart.

The result of these two improvements is that my in-line moisture filter is barely collecting any water now since most moisture ends up condensing in the compressor tanks or finding its way to the the drip leg, which means the soda is drier, which means my blaster works much much better. This wasn’t just some academic exercise, by the way; when I say the blaster works better now I mean it works a LOT better. I’m cutting through 3 or 4 times the paint on the Ducati piston barrel I’m working on than I was before I added the 2nd compressor or the copper plumbing with the drip leg, and with no more effort.

UPDATE: I’ve replaced the 2 portable compressors with a big Ingersoll Rand 80 gallon, 2-stage air compressor. The blasting cabinet is in the opposite corner of the garage from the compressor, so I ran 3/4″ copper up, over, down, along, into the drip leg, and then to the blasting cabinet’s regulator. Now I’m getting moisture in the tank, very little in the drip leg, and almost none in the separator for the regulator.

UPDATE: I added several LED lights inside the cabinet. These are under cabinet lights I found at Lowes, intended for kitchens, and the best part is you can daisy chain them together. I tapped into the switch for the cabinet’s original light, which means throwing that switch now gets you the original fluorescent lights as well as the LEDs. I also realized that since I’m only using this cabinet for soda, and since soda doesn’t etch glass, there’s no need for the plastic sheet inside the cabinet window obscuring my view. Between removing that and adding the lights visibility is greatly improved.

UPDATE: When I first tried this soda blasting business I originally bought a portable unit from Harbor Freight. It works really well but made helluva mess. My inspiration for buying the cabinet was to keep the mess contained, but the results were not as good. The reason for this is the portable unit is a pressure pot, whereas the cabinet uses a siphon system. In other words, the pressure pot’s soda is forced through the system with the compressed air, whereas the cabinet’s system (which was intended for sand, walnut shell, glass bead, etc.) uses suction to draw some blasting material into the compressed air stream. The pressure pot setup simply pushes more soda through, so it works faster, but it’s also less precise. So I’ve now combined the two. I took the crappy original gun from the cabinet (so I’d have a trigger) and ran the outlet hose from the pot through a hole in the cabinet and into the base of the gun where you’d normally attach the compressed air line. The soda isn’t aggressive enough to destroy the innards of the gun. All you have to do then is cap off the gun’s original siphon line. Now I can get a much higher volume of soda into the cabinet while dropping the air pressure to just 60 psi. The drawback is this gun isn’t very precise. So, when I first toss a part into the blaster I hit it with the pressure pot gun at 60psi and take off 95% of the paint and/or gunk. Then I run the pressure back up to about 100psi and go over the part again with the cabinet’s siphon gun to really get into the nooks and crannies. Overall, I’d say I’m cleaning parts in half the time now.

One other thing to keep in mind is that soda is friable; it’s not an abrasive. Only a little material is removed by scouring when the soda impacts it. Most material is removed when the soda impacts and then bursts into smaller fragments, popping the material off the part you’re cleaning. As a result, soda loses its efficacy once it’s gone through your blasting gun once or twice because it’s can no longer break down into smaller pieces. When it reaches the consistency of sifted flour, it’s past its prime and should be discarded.

I bought a set of used Marvic Penta wheels on eBay for Peanut. These are cast magnesium, and damn are they light! The front wheel (with wheel bearings, but without a tire or rotors) is 6.476 lbs.  The rear wheel is 8.126 lbs.  I’ll have to bust the aluminum Marchesinis off the bike and weigh them for comparison. Hopefully this will shave a few pounds of unsprung, reciprocating mass.

I finally have my track bike sorted out, so I now have space on the bike lift to start tearing into Buttercup. What happened way back in March was, although I thought I had checked her belt tension lately, I hadn’t. The timing belt for the horizontal cylinder skipped a tooth, which left the intake valve slightly open when the piston hit TDC. The valve bent slightly, and as it was slammed back into the head by the piston it then cracked the valve guide. A chunk of the valve guide broke off. As the engine continued to spin the intake valve opened, and the valve guide chunk fell into the cylinder. At this point the piston pounded it into the head several times, damaging both the head and the piston surface. Here are the sad photos.


Here are the valve guide chunks which fell out when I took the head off.

Here’s the piston with most of the carbon scoured off.


Here’s the bent intake valve.