Not trying to stop you because it probably can be done. I tried it last summer and couldn’t figure out how and bent a few valves trying. It’s well above my pay grade. There are a few differences in the set up which are not easily seen with the hydraulic adjuster setup. I pocketed the crap out of both intake and exhaust. Still hit.
I’ve still been wondering if adjustable cam gears would permit using them.
The lift you get from early cams is huge and probably too much. The rocker ratio of the 1200 is greater than the 1000/1100. The stock valve lift (not cam lift) of the 1200 is nearly the same as the early cams because of this.
To my untrained eye, the cams appear to fit fine.
I tried all the combinations of moving the belts a tooth or two or three forward and retard, and I could get it to run, but not on all cylinders- no power. I had my homemade adjustable cam gears and still couldn’t get it.
The other very big difference is the distance between the rocker shafts. The 1200 is quite a bit closer together.
1000 head spindle spacing
1200 head spindle spacing
Don’t go by my pics, the camera is at different distances, the 1000 spindles are wider set than the 1200 spindles. I think that is the biggest rub.
I will say, when I got it to run, turn over first , it was with the left cam ahead of the timing marks and the right cam behind the marks. When you look at the fact the cam is now closer to the centerline, it makes sense.
My head is spinning trying to remember and understand it.
My latest wild hair is finding a set of adjustable cam gears from Honda D16A1 car engine. I believe it is a 40 tooth and has the right diameter for the cam. Not sure on keyway.
If I try it again, I will pay someone to help measure openings and closings of valves in respect to crank. My gut tells me it’s a no-go.
A competent mathematician/engine builder could probably answer this, not me.
I almost forgot, the other important fact is with stock valve springs, they will bind. With everything torqued down, i can’t remember, but I don’t think it will even turn over. I’m pretty sure they will break. I did my other attempts using some from a cb750. They make higher lift springs for the 750, but probably weren’t the strong enough. I had an extra washer under each. If it could be found to time it to use these, custom springs or a crossover set of springs would be needed.
In my opinion, the fastest way forward is to put the 1200 heads on. You might be surprised at how well it performs with your carb setup.
Good luck, let me know if I can help.
Is she doing better?
