I pulled this apart since it had shifting issues, especially downshifting from 5th down. I found out recently it was parked at 800 miles due to shifting issues- replacing broken shift drum ‘wheel’ (part with the pins that the shifter moves). I found a bad bushing, nobody had a new one, so I made one...

I have what appears to be the same adjustable DC power supply. Very handy for testing and verifying wiring harness for bikes that have no battery. So far it appears to be working well and no issues. I like the adjustable current also. Interesting that they used not only differing lengths, but slight...

Bearings in the cases.
Next I will fit the gearbox and verify no shim changes are required.
After that- time to install crankshaft, gearbox and finally put cases togehter.

I really took this one to make sure I got the shift forks back in the proper orientation/order etc. Everything looks like is should be for a 500cc or larger. I understand the same person designed the 650 twin Tornado (which I had once) and I think one of the GP bikes. Oh, I think the 250 four street...

I was checking for spark- but then discovered why it was likely parked. It is an early version of this machine, still with points (later were electronic). Capacitors were toast and corroded. Flywheel nut was loose as was flywheel- so someone must have been in there then never fixed it. Popped engine...

Well…I bought that parts engine since this was coming. The next project. The kickstart shaft is sheared, so I got a very good price. I will pull the engine quite soon. I have been checking electrics a bit. I would like to see if there is spark- might have to spin the rear wheel with my wheel balancer.

They did make road racers with them- Zanzani did quite a bit. The factory did some- but mostly concentrated on the 250 and 350 fours that did very well. This engine is developed from the Motobi engine. Benelli started with 6 brothers - at a point in the 50s one of them broke off from the others (can...

I have no idea why they use four large main bearings, with the outer ones being dual row. It seems overkill, but there must be a reason. All the bearings are SKF of the same type they still make and use. They can run pretty high rpm, they have a short stroke, although a pretty short con rod. I expec...

I have bearings all out and working on cleaning/vaporhoning and then ordering bearings. The main bearings (4) are seated by circlips, so that means driving them out on the inner race. In any case, after getting them out and looking at them I am replacing them all anyway. I see signs of corrosion fro...

I heated it up with a heat gun- but not that much. It came right apart. Getting the crank out of the left side was a little harder. But I used that air hammer and the trick you had. Popped it right out. I will be checking runnout and see if still in spec. I don’t like the way the bearings feel, so w...