79 F cams compared to 79 SF cams

[79XS11F]

Are these cams the same between the standard and special models in 1979?
Rob

[79XS11F]

I was asking about the cams because I may find myself doing a head switch out this RAINY weekend. I just pulled the head off my backup 1979SF engine and it is in very good condition with minimum carbon buildup. Cam lobes and bearing surfaces all look real good with no scoring. It's in better shape then the head that is currently on my bike. All valve seats look real good and the combustion chambers held gas so the valves are in deed seating and sealed when seated. I will clean this head up in case I get that low compression reading on # 2 Saturday morning.
Rob

[trbig]

According to the Yamaha parts list, they are the same part number. Just remember that the cam caps should stay with the head they came with... not with the cam they were with.


Tod

[rover]

When I bought my SF (sn 3H3000043), the dealer told me that when they were designing the F back in 78, a few were made with hot and not so hot cams, but due to poor rideability, ALL SF's that were sold had the stock E-F cams. He tried to get some of the hotter cams and/or specs of them, but had no luck. (Yamaha insisted that there were never any hotter cams.) He thought this SF had the really hot cams, but later measured them, and they were the same as the other cams. He always said this particular SF was MUCH faster than any other XS 11 he has ever ridden.

[79XS11F]

For sure that is the plan trbig. I fact I would do a complete head switch out. I will prep this one on the bench so that if I need to use it my bike will be down for the shortest time period possible. A complete head switch out would be pretty fast to do. I was pretty sure that the heads and cam lift would be the same but wanted confirmation. the XS parts look up site lists the cams with different numbers but dose say originally from the E and F model
Thanks
Rob