Originally Posted by
JRgraham
I have an old original YS 60 that has just been pulled from a box, not ran since the late 90's. I set it up yesterday on the test stand and after a little love, she fired right up and is running really strong. Really good idle, good transition, and seems to be pretty sensitive on the needle for high rpm's.
I am just wondering, its been ages since I have set a pipe, what is a good pipe length? I am right about 15 1/4 inch range from the plug to the first high point on this pipe, which I believe is an older hatori. I am uncertain the number on the pipe. I think I must be pretty close to the right length, I have not fried a plug and the needle is sensitive.. I just really need some confirmation.
I also have an old 61 long stroke in pieces needing gaskets and bearings, otherwise its practically new, that I will get rebuilt and run as well.. will need the same thing here, what pipe length?
The 60 I have running has just a 11x9 APC for the moment, I couldnt find anything better locally, but will eventually order up some 11x10 - 11x11's once I know they are worthy again.
Also, I have yet to really search around, but I am assuming gasket kits, bearings and such are still available for these babies?
Thanks guys.
Hi JR,
The length is fairly close as I recall, for even larger loads than what you are running now. From memory, smaller props such as 11x7 required a bit shorter length. Produced considerable increase in RPM.
I ran the short stroke for several years back in the mid 80's. One amazing little mill with terrifc transition and idle. I stretched the pipe as I recall to around 16" (I think) and was running 12x11's at around 11K, before soft mounts.
The long stroke was tuned about the same but turned 12x12 and up to 13x11 at around 10K. Not quite as well mannered as the short stroke particularly its idle, but very very good, and better than most. Note these set-ups worked great on the larger 60 sized model with around 800-850 square inch wings and longer fuses. Just before the YS 4 strokes hit the pattern scene. What I ran on my Joker and Eclipse as a matter of fact
On your smaller model, prop clearance might be a problem. "I think" you might be leaving power on the table by using a longer pipe tune, BUT hey, the engine should run just fine and with the lighter airframe, you haven't compromised much re: power. See how she transitions with the light load and stretched pipe, and shorten a little to clean it up. BTW- KB1L plugs were outstanding and long lasting, on 15% nitro.