Update on the 3 1/2...
Update on the running problem.....
Last weekend I checked out the ignition. The stator coil for the ignition circuit checks out fine. The problem is definitely fuel and not spark. I started it up and ran it a bit. The front cylinder is definitely warming up much more quickly, but, the rear is firing, as it runs real fast if I have the enrichener on for the rear cylinder, much more so than the front, but, in both cases, turning the enrinchener on/off affects the engine speed as it should. That's all the time I had last weekend.
Wednesday, I had to take the Thruxton to Hermy's for a recall service (side stand spring). While there, I paid a visit to Herdan Corp (
https://herdan.com/) and picked up gasket sets, fuel filters and float needles for the VHB25B Dellortos.
I was about to pull the carbs for a full tear down to inspect and clean, but, first I went for real low-hanging fruit. I pulled the jet holders and measured the fuel in the bowls, it was about the same. Just for grins, I swapped the float bowl nuts (which also hold the main jets) started it up, and warmed it up. It idles way too fast with both enricheners on, so, I alternated them until it was warmed up and got equal temps on the exhaust ports and got it to idle with them both off. Then I took it for a ride. It ran great, most of the time, but, sometimes hesitated under 3/4 to full throttle. I think there is likely gunk of some kind in the holder/jet that was in the rear, and by removing them, I disturbed it enough to get it to at least run on both cylinders. I’ll pull both out and take the jets out and give them a good cleaning. It idles fine once warmed up, and is running well aside from the little hesitation that it does under power (thinking main jet gunk), so, I likely won’t pull the rest of the carbs apart if cleaning the main and holders does the job.
Pic after getting back home from riding it late yesterday afternoon.
I definitely love riding the Morini! It just may be my new favorite vintage bike to ride, a title that my Ducati 750GT has had for the 2 1/2 years that I’ve owned it. It is like a small block Guzzi, but, much lighter, and of course, the engine runs at higher revs, but, is not buzzy or peaky or anything like that.
It feels as light to ride (though, is actually about 50# heavier) as my Ducati Monza 250, but, with nearly twice the power (not that it is powerful, but, the 250 is kinda slow). I’d love to be able to find a double drum brake for the from though, as the brakes are a little lacking, but, adequate for its light weight. It definitely feels more nimble than my '76 Honda CB400F, which is of course, similar in displacement and vintage.
