Ok......I stripped down my 28cc McCull. weed trimmer and cleaned up the parts. I cut down the ducting shroud so that I have a coil bracket. I am in the process of trimming the "fat" off the flywheel. I need some ideas as to how I might mount the prop drive nut to the flywheel. This is a short-shaft model and I'm thinking of chucking the 1/4" square drive extension( that acted as the flywheel retainer nut on the original) into the lathe and trimming off the excess and turning a drive nut out of aluminum to be pressed on the trimmed down extension and pinning the two together, but that almost seems too complicated. I like cheap, but I like easy even better! Your ideas are greatly appreciated!
XS

On the square drive nut, you run a tap drill for 5/16-24 through it and tap it all the way through from the old threaded side.

Then turn the nut around with a big washer behind the flats and a big hole in your prop. The prop is up against the flywheel that you shaved the fins from.

The nut and the prop hold the flywheel on.

On my flywheels, I took pliers and broke the fins off. Then I used a air powered die grinder to smooth everything over.

You can use a High Point balancer from B&B or a Dubro Balancer to balance the flywheel. If the flywheel has the key cast inside it, turn the arbor cone on the back side of the flywheel around and use the flat side against the flywheel.

Enjoy,

Jim

Ken Lambert has hubs and spring style mount mufflers for these engines. Mine will be coming from him. From what I understand, you have to cut the drive extension off. Can you post a pic off how you cut the coil bracket? I have not pulled mine down that far yet and would like to see how others are doing it.

He is a picture from Carr Precision where you can get the parts if you like. The pictures show how far back to cut the bracket.

Carr doesn't cut down the mag bracket. He makes a mag coil mounting plate.

My Mac 32's have C-H ignition systems on them. I didn't use the coil or the bracket.

Enjoy,

Jim

What's up, I got two of those 32cc mac, My ? to you is how do they run with the ch and did you buy the kit from ch them selves ? What size carb are you using and what rpms do you get with whatever size props you us?

I bought the C-H ignition set-ups from C-H themselves. This included the hub with the timing magnet and the bracket to hold the pick up sensor, as well as the rear mounting plate. I bought the mufflers from them too.

The sensor mounting bracket is made in a mannor that it only fits the engine at the correct position. This means that there is no problem getting the timing set to the right advance.

I used 1/2" walbro (32) carbs like is on the Zenoah G-26 engine.

I run 18-8 props. The stock one turns 7400 rpm and the other has a cylinder modified by Mr Grant at C-H and it turns 7600 rpm.

They look as though they were model airplane engines from the beginning.

There was no cutting or sawing to the engine except the plastic back plate.

Enjoy,

Jim

Thanks for the reply but it does not sound impressive at all since my homelite gives almost the same numbers with a little mod. I got one of mine taken apart and yes compared to the homie it was very easy to convert. If you have one on a plane how is the vertical?

It'll climb at a steep angle but will not vertical.

Enjoy,

Jim