1972 Norton 750 Commando Rebuild
I bought this bike in Denver with 21,000 miles on it, found it on the internet. It is a 1972 Norton Commando Roadster with the optional Combat engine. I got it from the original owner, along with the original paperwork to prove it. It was sold in New York city. The paint job is original and the owner said that the pinstriping was dealer applied. It was beautiful but seemed to lack the pep my other Norton had.
I found out that the cam lobes went bad due to not being hardened properly. According to information I found, several of these went out before anyone knew that there was a problem. I had wondered why it lacked power and seemed to need tuning almost constantly. The worst lobe is worn down 33 thousandths. I had been riding it this way all over the state.
You can now see the result of this problem. I sent the engine off for a new cam, main bearings, etc, total bottom end rebuild. I also had some modifications made that were found over the last 30 years to add to the reliability and life of the machine. I sent the bottom end of the engine to Old Britts in Auburn, Washington, which is about an hour south of Seattle. They would machine the crankcase for better oil scavenging, move the breather to a better location, replace the cam and rebuild the entire lower end. The following three pictures belong to Old Britts.
This is a shot of the case being milled.
This shows the material that was removed to allow oil to pool and return to the tank. The shiny, machined outline gives you some idea of why the old area wasn't too efficent. The area has been circled that was modified. The oil can now run straight back and pool at the pickup for the pump.
The crankcase breather, that didn't work very well, was moved to a better spot on the top of the timing case and the old hole was covered with a custom made plate. This is a shot of the engine at Old Britts, the owner, Fred Eaton, sent me pictures of everything he did. He also provided a lot of information and I bought most of my parts from him and his wife Ella. They are great people to do business with. Most of the engine shots on their site are of my engine.
It was a long slow winter and as time passed more and more parts came off the bike. Finally I had a bare frame. It would be a shame to put new and rebuilt parts in a frame like that so.........
Frame was powder coated in along with all parts that would come off. Wheels are relaced with new polished stainless steel spokes. Cylinder barrels were powder coated. New lifters will be installed to run on the new cam. The transmission got new seals and a final drive cog change from 19 to 21 teeth.
The reassembly adventure has begun. If you are at all interested in this type of thing here are some pictures and some brief explanations.