Yesterday I managed to make some good progress on the Morini. I fabricated the bracket to adapt the Ninja caliper to the front wheel, and then also ran the line and did an initial bleed on it. I need to bleed it better (couldn't find part of my one-person bleeder and was by myself) but it's enough that it works. Then I made the new clutch cable (which I cut just a bit too short and will need to make again... but I was able to make work for yesterday). I also welded up the bracket to the rear brake lever that will allow it to actuate the Ninja rear master cylinder.
And lastly, I welded on a larger foot for the kickstand.
Fabrication always goes slowly when you're trying to get all of the dimensions just so, but I'm happy with the results. The caliper lines up perfectly, and it moves evenly with no binding, and the thing does stop with the brake handle. I couldn't do the rear brakes because 1) the master cylinder I'd bought was seized up (so I need to order another one there) 2) I needed some different metal than what I had to make the adapter bracket for the rear caliper. So that'll be another day.
After getting it all together, I took it out for a quick ride around the property and then around the block. I didn't spend much time riding it but I wanted to get a more complete functional check.
The bike does have a 6-speed transmission, and all 6 gears work with it shifting well both up and down. It feels like the clutch doesn't fully disengage (this is mostly evidenced by the fact that at a stop you can't shift it from 1st into neutral) but I imagine that as I ride it more and it gets some fresh oil in, that should likely improve. There may be some other items, but the clutch does not seem to be slipping.
The gearing on it is very short, which as I read was intentional for off-road. That's a good thing. Once you get the bike moving (it doesn't have much rotational mass unlike the BMW, so you do need to be more careful with the throttle and clutch from a stop) it has what seem to be very appropriate gear ratios for off-road biased riding. In 6th gear if the speedometer and tachometer were right (which is a big "if" in both cases), it did around 55 MPH @ 4000 RPM. That doesn't feel stressed on this engine or the bike in general, really seems appropriate for what the thing is.
I've been riding the BMW a bunch, and so of course that's what I'm used to for an off-road bike. I think this is ultimately a good bit better, but it is different. One noticeable difference is the handlebars are shorter, so of course that means the thing turns quicker. I need to see how I think I like that in the end.
I also confirmed and was able to evaluate the overall engine running. As I'd mentioned before there was a work order from the previous (now deceased) owner saying that the thing would miss above 4,000 RPMs. What I really found was that it felt like it wasn't so much RPM based (although 4,000 is where it more or less becomes the most evident) but is really more load based. I'm pretty sure the issue is the ignition system, it feels like the coils are weak or otherwise breaking down and not able to produce the voltage required to jump the spark plug gap. I've had this happen on several cars before and the behavior is almost identical.
It runs smoothly and works fine at lower power settings, but ultimately I do think the 12V conversion and electronic ignition is in the future. Not immediately, but those are smaller projects I can work on as I have free time here and there. Really, now the bike is rideable, and I want to ride it more around the property and see how I like it while also looking at what I can do for minor upgrades here and there. I'll get a 12V voltage regulator coming that I can use as part of doing the 12V conversion, found some 12V turn signals (LED - will help improve visibility/safety), and will need to find some 12V bulbs (probably LED equivalents) for the instrument cluster. Minor items that improve the functionality and are reversible if desired in the future.
The ignition system, that requires some more thinking on. I keep on coming back to wanting to use LS coils because they're so prolific.. Also since the switching is done by a low-current 5V source and they self-limit the dwell (you can make the dwell shorter, but in this case just letting it stick to the max 8ms dwell is fine). The catch is then designing/getting a circuit that will fire the coils based off of the magnetic pickups for each cylinder. I'm not an EE so I'll likely need to get some help on that one if I decide to go that route, as I haven't found any products that do this job.
The other idea that I don't like as much but would work is using Ford COPs with conventional spark plugs attached. The Ford COPs are 2-wire and fire more like a normal ignition coil, as in break the ground wire to interrupt current flow and cause the coil to fire. Pairing that with GM HEI ignition modules should theoretically work. MSD makes some modules that advertise multiple sparks for 20 degrees of rotation, but that would be 20 degrees with 8 cylinders, not with 1 cylinder (which is what this would be). I don't think that would cause a problem necessarily but since good HEI modules tend to have some logic around RPM built-in from what I can find, that seems like it would be easier to hook up but may produce additional issues as I'm trying to get it work.
Probably the real easiest would be to see if I could find some new ignition modules from Ducatis (that's whose parts bin was raided for most of the electrical on this) that would otherwise bolt up but just use 12V. That would probably be the simplest way to go, but if I'm going to buy new components and do this, I'd like to be able to increase ignition energy and expand the spark plug gap. In the past I've found that's one of the best things you can do for engine running and responsiveness.
It's possible this running issue is carb related, but I doubt it. After having gone through the carbs fully, they should be clean, I'm not seeing any debris in the filters that would indicate fuel flow should be restricted, and even still it wouldn't be such an on-off type of switch that goes with throttle if it was - the float bowls would empty at a particular rate and then there would be a difference. These carbs just have a metering rod and orifice so they're really quite simple, and the thing runs well otherwise.
I'll need to ride it more than around the block to truly get much of a feel for it. But it's immediately noticeable vs. the BMW how much more compliant the suspension is, clearly tuned more for the bumps of off-road. Then again the BMW is so old the suspension is probably also largely blown out, but the Morini flows over the imperfections more. I'm not putting much trust in the speedometer at this point (should verify with a GPS) but I was immediately comfortable riding the bike on gravel at similar speeds to the BMW, although the narrower front wheel did seem a bit less stable, which I suppose is expected.
Really nice to ride this thing, and I'm looking forward to making continual improvements and riding it around some more.