72 Benelli 175 Enduro

[Lotus54]

My quick setup just to see how close. Next I did a better pointer and more secure wheel to check (it was the same).

I want to have a mm BTDC to use if I need to adjust later. Easier to check.

[Lotus54]

It was sort of a bugger to get the flywheel tightened with correct timing.
The way the Vape system works is the flywheel key is left out- and just the taper holding it in place. I finally got it by holding the clutch with a chain vise-grip to keep the crank from turning and holding the flywheel.

Head it just finger tight- waiting for a copper head gasket I am going to try out.
Next finish polishing and fit into frame.

[John H]

Interesting how large the fins are on the head and small on the cylinder. What does the combustion chamber look like in the head? Wow! no key in the mag is interesting. You have probably seen Ossas, Montessas and Bultacos that sheered the key.

[Lotus54]

I think the head is mostly marketing. The older version of the same engine had a much smaller rounded head. But they were primarily road bikes. So perhaps this ‘enduro’ (really a dual sport) would benefit from extra cooling when going really slowly?

I’ve never had a flywheel key shear myself, but have heard of it happening. Those are all much higher output engines- this one is pretty mild and hopefully will be no issue.
Vape sells these for a lot of bikes and it appears that is how they always time them. I did put some locktite on the shaft and tightened well.
Perhaps once I’m convinced the timing is correct I will cut a slot for the key? I’m not quite sure how I would do that of course. I’ve seen where a tool is pulled through to cut a square hole- but I would have to research a bit to see how to do an inside slot with a small opening to access.

[Lotus54]

Here is the older version of the head.
This is the Benelli ‘Volcano’ using the same engine (they called it a 180) in a mini frame. I guess only 200 made and I’ve always wanted one. I’m not sure why exactly. Prices are through the roof now.

[Lotus54]

Almost ready to install

[Lotus54]

I know, I should have waited until I was just a bit further along and cleaned up my lift…oh well, at least I’m not out on the streets getting into trouble.

Wiring harness is just roughing out. I have a diagram almost done (I’ve made some changes as I go). Waiting on a terminal block and some more shrink tube of the sizes I want. Ordered big rolls, so should last me a very long time.

[John H]

Looking good. Wiring is one phase of a build I am not that good at, especially with older Lucas and Miller parts.

[Lotus54]

The wiring is 99% done. I have a little cleanup to do on the diagram, but it is close also.

I made a mistake when installing the engine. The skid plate from bolt goes through the case- but you can only put it in when the engine is dropped down. I didn’t notice that when pulling (or forgot).
So had to take the bolts out and drop it a little bit. Didn’t take too long, but dumb anyway.

I put on a new clutch cable, but I didn’t like the way the cable end when into the case. So I made up one out of aluminum rod on the lathe. It came out well and fits well.

[Lotus54]

Getting closer.
I made a throttle cable and got it installed.
Wired up kill button and installed headlamp- tested and everything works. Well, still waiting on new front brake switch.