Vintage Motorcycle Eccentrics

I took it for a longer ride today- ran great!
I found out why cold start was poor- the cable going to the ‘splitter’ that opens both of the starter valves had broken.

I need to get some 3mm screws to bolt down the handlebar switch, a few other little things and ready to put some miles on it to break it in.
I turned over 5,000 miles on the speedo.

I forgot to take a picture on the ride.

Great day for a ride up the Elwha (and other places)

The throttle cable adjuster had broken. I’m going to replace the throttle and splitter with a two-cable setup, but in the meantime, I made a new adjuster. The knurling is not very good- but it is functional

Knurling takes some practice to get a perfect pattern. What brand is the throttle?

Tomeselli.

I’ve done a lot better knurls before, but this was a different tool, different lathe and different material.

I got a dual cable Tomeselli throttle. This is not the desmodronic type that many modern 4-stroke bikes use, but both cables are pull to open.
I made up both cables from some Venhill kits I have. The throttle is quite a bit lighter without the splitter (and old upper cable), smoother also.
I then made up the ‘top’ cable for the two enrichers on the carbs. It had broken in the spitter. So now I can just pull the lever on the handlebar for cold starts. It starts really easily with that active, but not won’t start without it. I was just pulling on a cable until I got it fixed- much better now.

I got one new silencer in from Germany, that is all they had. But it does replace the rustier one. I will keep looking for a right now, but will start working on cleaning up the old ones really well and see about rechroming. The baffle system comes completely out.

Tomaselli accessories are always high quality unlike some Amal items. I like the idea of changing to twin throttle cables
all the way too.

The manual has a very slow breakin recommendation. On this one, mostly the pistons (rings) that would require it. Tolerences are fairly snug so I don’t want to push it.
I have a spare headpipe, so I think I will weld an O2 sensor bung on it and go ride it with my readout box, so I can verify mixture. I think that is the most important on a 2-stroke, get too lean and it gets hot and…

I know what 'lean' does to 2 strokes, put the wrong gas in the Lawnboy last year and stuck it. How do you adjust the oil mix on the Benelli 250?

The Benelli is pre-mix. I’ve been using Motorex full synth 2-stroke at 50:1
My KTM 300 called fro 60:1, my Beta averages about 88:1 (oil injected).

With the oils in 1972, they called for 5% - but even back in the later 70s, I ran much leaner (I think 40:1) with the oils that had come out.
BUT, I want to make sure not too lean. That will kill it a lot faster than lean oil (well, from what I’ve seen). Plus oils avaliable now are very good.