70 Commando top end rebuild complete

After experiencing the RHS plug always fouled after any length ride, I decided to pull the head and send it off to Jim for a rework. No amount of fiddling with the carbs or plugs would remedy the problem. He reported that the head was in need of a rebuild. It had seen a lot of miles and the PO had installed the rocker spindles with the flats facing the wrong way around and that the RHS inlet was leaking a small amount of oil into the head, thereby contributing to my oily head, plug fouling problem.

List of work / parts in this rebuild:
Rebuilt cylinder head with new kibblewhite springs and black diamond valves. New mushroom valve adjusters. All by Jim. Barrels rebored to +.020 with new JCC pistons and Hastings rings. CNW ARP barrel nuts. CNW exhaust nuts and SS rocker oil feed lines.







Got the bike all buttoned up and was excited to start it for the first time in a few months. No start. Usual starting sequence is key off, fuel on, Mikuni enrichener on, kick twice, key on, kick to start. No luck, just a couple of backfires, that was about it. Here’s a video of what didn’t work. It was supposed to be the start video:

http://youtu.be/w4FVvl8WQi0

I just about gave up, go get some lunch and try again later. One more try, I thought to myself. Hmmm, cold day here in Malta, just might try leaving the enricher on. Success, the bike started first kick.

Question – am using 20w50. What do you use for run in purposes? Lighter oil for the first few hundred miles or stay with 20w50?

Wont be going far in the next few days – it’s pretty crappy outside


Still a few things to sort out. Not happy with the fuel lines so close to the cylinder head for example.

I did the same top end rebuild and rebore a few years back. I did use break in oil for the first 500 miles. Then switched to 20/50. Might have been over kill but I felt good about it. As for the enricher even in the summer I use it for the first start of the day. In cooler weather all the time when starting. Malta looks like a very nice place. Bet the Norton sounds great going down the narrow streets with all those stone buildings.

Whenever I have a starting problem, it's electrical! Unless I flooded it!

Most modern vehicles don't use running in oil. I never did and never had problems with all the rebuilds I did over the years. The important thing to do is drive it hard and never nurse it in the first 100 miles or so.
Dereck

I want to go to Malta. Hear it's all built over now no fields left , I hope that person was wrong. As for break in oil , I use a good 20-50W and do an oil change at about say 3 or 400 miles ( kms. here and in Malta ) to an even better grade or Brand. The goal for me is to work towards 15W50 Synthetic eg. Mobil 1, once everything has bedded in and is seated nicely. No filter to change on a 70 .

I use 5 - 40 Synthetic Rotella diesel oil when the weather is cold. 20-50 v-twin if the weather is hot. Nothing different for break-in. Jim

Weather gods smiled on Malta today. Filled the bike with 10w40 and put 50 uneventful miles on the clock. The bike ran and handled very well. Will torque down barrel and head tomorrow am.