[gary856]

fixing a 916 head tat broke a belt and bent all the valves. was going to use a some valves from a 748 head that i saved, because they are supposed to be the same. cant use the valves because they measure 17.5mm tall were as the valves need to be 106.5mm. the valves measure 33 & 29 mm. arent 748 and 916 valves supposed to be the same except for the 2002 lower head? cant cut the valves and taking 1mm off the shims doesnt work either. any one got some correct valves, need 2 intakes and 1 exhaust as i have one good one.

 

[Namor]

The 916 and 748 heads are the same for base models. I swapped them years ago with success. More details for your struggle are necessary.

I have also put 916 valves in 748 heads with no problem after a proper seating.

 

[gary856]

got a set of valves i saved from a 748, dont which year, but they are107.5mm instead of 106.5mm. diameters are the same though

 

[bradblack]

the 748 chamber is smaller, with the seats not as deep and the valve heads sit 1mm further out if the makes sense.

 

[gary856]

the 748 chamber is smaller, with the seats not as deep and the valve heads sit 1mm further out if the makes sense.

but arent the valves the same hieght from bottom of the valve to the top of the stem? i have one exhaust valve from a 748 that is 106.5mm the other set also from another 748 measures 107.45mm.

 

[bradblack]

i'd expect there to be an extra mm between the valve head and the collet groove. groove to tip should be the same.

i can't argue with the physical reality you have in your hands though.

 

[wdietz186]

When Ferracci redid the heads on my 851/955 they installed 1mm shorter valves to compensate for the valve seats being sunk because of being recut. Possibly the reason for your difference?

 

[gary856]

Got a set of 916 valves, bike is running good now.