Topic: CB750 F pistons, what rings will work???

[Soos]

I broke a used ring installing my "f" 750 pistons, and am in need of another set.

Is is possible to use "k" rings on these pistons?
Are the thicknesses the same?

I have found a set of 1.0 OS rings for a steal of a deal on Fee-bay, but is it safe to use OS rings, and re-cut the ends to get proper ring gap?(and they are for a K motor)
I'm assuming that the OS rings will probably not be the best thing as they will probably be sprung too much, and cause un-nescarry heat/friction due to being set up for a larger bore.

Am i f*cked, and have to spend mass $ to get rings for these F pistons through DSS?
they want $17 (euros at that) each piston ring set...
Thats 68 euros, before shipping. So i'm guessing 80-100 US to get a set...


Anyone know of somewhere else to get some F rings?
Anyone have a used set they want to sell???


l8r

[dusterdude]

not sure about a k ring,but you can file the oversized ring

[rbmgf7]

i saw a guy on ebay with 2 750f std. ring sets. there was an old post about modifying the F pistons to accept 69-76 rings. apparently the 1 and 2 ring is thinner on an F but the oiler is the same on all. so all you need to do is machine (or find a machinest) to enlarge the 1 and 2 ring grooves. now you can use any 69-76 ring sets. sure it'll cost more but in the long run will save you.

[Bodain]

Your only screwed if it's a 78 F. Since 78 F rings are pretty much not available. If it's 75 /76 F... It uses same as K.

[MRieck]

Your only screwed if it's a 78 F. Since 78 F rings are pretty much not available. If it's 75 /76 F... It uses same as K.

That's not really true. There is a part # that is not for F2/3 that includes the proper top ring. I know this for a fact as I ran into the ring problem and someone on the board gave the a cross #. Unfortunately Honda doesn't give the cross #and I don't have it. The guy who provided it was from Canada. It worked out perfect

[Soos]

The ring thickness I broke is 0.058 thick (1.47mm)

Anyone know if the secvond ring on a K piston is the same?

The 65mm (64? - 836 pistons) pistons that are from my '73 750 is the same thickness.
But they are aftermarket(obviously) is this the "norm" thickness of the second ring?


l8r

Have to do more searching i guess, i came up with nothinbg last search on this info...

thnx again

[Kevin D]

The ring thickness I broke is 0.058 thick (1.47mm)

Anyone know if the second ring on a K piston is the same?

edit: I repeated the measurements with micrometer instead of caliper and 6 hrs sleep.

Second ring measures .058", 1 piece oil ring .110", top ring .057"

71k1 standard bore, original piston

[Soos]

Ok....

Both top and second ring are 0.058 huh?
only tyhe second ringh on these F pistons are 0.058, the top is thinner, have yet to measure it though.


Since a 750K ring will work, anyone have any laying around in remotely runnable condition?
If you have 1 or more laying around I would greatly appreciate it if someone would sell me theirs!


l8r