Compression on the cub is at 160-170 PSI (I tested on 3 different testers, every one is different).
Got 155 on mine, which the threads are not quite as long as the spark plug threads.
Got 160 on one that is slightly longer, but not as long as the threads on the spark plug.
And got 165 on one that is about right in terms of length of threads.
Wondering if I can safely run pump gas... been mixing half and ha;f but that is really getting old, and expensive.
Just bought another 5 gallon of 114 today, and mixed it half and half with 93. So I got 10 gallon, and that should last me a few weeks.
Running my timing on +4 right now, thinking of trying +6 as I didn't play with the timing yet. Really haven't put too much time on it. 20 gallon so far in 2 months, which isn't alot considering how much I used to ride.
Just wondering what you guys thought about that compression, and the octane this motor requires. I can't find race fuel any cheaper than $9 a gallon, so it's really getting to me...
Wondering if it would be safe to go with 93 pump... and if it would be safe to do so if I planned to go with +6 timing.
Kevin Herr, the builder of this beast, says to go half and half like I am, to be safe. He also says it most likely could run on just pump alone. But to be safe, mix.
Just looking for others advice, ones who ran cubs and such before...
Mods are in the signature... and I am running 158 mains, 50 pilots, CEL on 3rd clip with air screw 2 turns out. It is spot on with the 50/50 mix of gas, with Klotz at 36:1