75 head refitting

Any videos on refitting the head, 75 Commando motor in frame

I think this is shown for a combat here:



The 75 850 should not be too different.

I did my '74 be reviewing this and other videos i'd found and following the workshop manual plus advice from owners on this forum.
Having the pushrods shoved up into head, off the rocker seats for maximum clearance is key. Use some elastic bands to hold the rockers and pushrods up while positioning head. The angle of back tilt is important to get rods into passages.
Once head is Squarely above block, let the rods fully drop down before trying to lower head down. Then once down but loose, work to wiggle rods into the rocker ends using a long thin screw driver etc, a light into the exhaust cover opening helps to see where things are.
All that is the toughest part of the job.

Thanks.

I just rebuilt an Atlas head in the frame, I thought it would have been easier if I left out the exhaust rocker arms out. Not a terrible job have patients and make sure you don't get pushrods mixed up

I've found a pick with a crook shape handy to move the pushrods into position. Put some grease on the pushrod end that goes into the lifter but not on the rocker end. Once you get the rocker ball situated into the push rod use a rubber band on the other end of the rocker and the rocker cover stud to hold the rocker into the pushrod top.

In all the years of ownership and rebuild my Norton as well a few others over the 46 years the best way for me is by the book, its a lot easier when the motor is on the bench and on a stand but even in the frame the book is the best way, I just use my fingers to hold the PRs up to drop down to the lifters when fitting the head, I don't need rubber bands or anything just my fingers on one hand and the other hand holding the head into position, works for me every time, then the first bolt and a small screw driver and torch to make sure the PRs are put in place of the rocker arms, so simple really, no need for rubber bands or anything else except fingers and hands, really its not that hard to do.

Ashley

ashman said:

In all the years of ownership and rebuild my Norton as well a few others over the 46 years the best way for me is by the book, its a lot easier when the motor is on the bench and on a stand but even in the frame the book is the best way, I just use my fingers to hold the PRs up to drop down to the lifters when fitting the head, I don't need rubber bands or anything just my fingers on one hand and the other hand holding the head into position, works for me every time, then the first bolt and a small screw driver and torch to make sure the PRs are put in place of the rocker arms, so simple really, no need for rubber bands or anything else except fingers and hands, really its not that hard to do.

Ashley

Click to expand...

I have done it that way a dozen times. Only had an issue once when the rocker end wasn't in and I wondered why I couldn't finish the job ...

ashman said:

In all the years of ownership and rebuild my Norton as well a few others over the 46 years the best way for me is by the book, its a lot easier when the motor is on the bench and on a stand but even in the frame the book is the best way, I just use my fingers to hold the PRs up to drop down to the lifters when fitting the head, I don't need rubber bands or anything just my fingers on one hand and the other hand holding the head into position, works for me every time, then the first bolt and a small screw driver and torch to make sure the PRs are put in place of the rocker arms, so simple really, no need for rubber bands or anything else except fingers and hands, really its not that hard to do.

Ashley

Click to expand...

The question is about fitting the cylinder head in a "commando frame "
Not on the bench,not in a featherbed frame

Here's a tip for keeping the rockers in place while you torque the head:

baz said:

The question is about fitting the cylinder head in a "commando frame "
Not on the bench,not in a featherbed frame

Click to expand...

I have replaced blown head gaskets for mates while the motor was in Commando Frames doing it the way of the book as well my own bike before I converted to the Featherbed.