Eric The Leg
Husqvarna
AA Class
In other words "Be very careful and look at all of the photos when I buy parts"Troy,
The 79 250/390WR's used the long style brake stay up until frame serial number MM5594 after that the WR's used the later style like the 1980 WR's have. This was due to the rear hub and brake plate was changed to the 1980 WR/OR rear brake plate and hub. This also required Husky to change the swing arm also.
There were many mid year changes on the 79 WR's. Probably more than any other model year. There was also frame changes and the forks were changed mid year. Also the Ohlins dampening specs were changed mid year.
Marty

The head-to-cylinder is flat-to-flat, (as opposed to valves or flywheel where there's a clear inset), so that differs from lapping I've done in the past. A brief search didn't turn up any videos. do you just do small concentric circles to lap it (like if using emery paper on a flat surface to flatten/shave a metal surface)?
Also, do you do that while the engine is fully apart (benefit would be easier to clean, concern would be oxidation, I suppose could coat it in oil while doing remaining engine work...) or wait until you're about to put the head on to lap it (benefit is less concern w/ oxidation, drawback is harder to clean to 100% certainty of no grit in cylinder afterwards)?
Or is this outlined in the engine manual that I probably need to buy from Phil on CD?