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.

JR,

On the 60 SS: 11x7, 11x8, 11x9. You can go higher but why? Torque at ~15K so tune to suit on an 11x7 or 11x8.

on the 61 LS: 11x10, 11x11 up to 12x12. Many like 12x10. Torque developed at ~11K so tune to suit on a 12x10.

Bearings are no problem - try Boca. Gaskets trickier - contact Rich Verano at YS USA.

David

Okay, good. I must be close to the pipe length then? at about 15 1/4 from plug tip to first high point on the pipe?

What frames are these engines going into?

personally, I'd tune the SS on an 11x7, 11x8. Try propping down and check the numbers and needle. Kevin can give you a ballpark length for the exhaust but I'm not sure how that older Hatori behaves (or rather the engine on that pipe). That said, 15" is about right propped down.

David

Well the .60 ss will go on an old chaos or dirty birdy I am rebuilding for awhile (not real sure what model it is). I want to give it a good test bed. I dont have anything else right yet, but my interest in classic is growing, and want to get an LA-1 or 2 or something. we'll see when time comes.

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.

Thanks a lot Matt. Well this is not really new territory for me, just resurrecting history more than anything. Its been a looong time since tuning these with pipes. I was an old die hard pattern guy back in the 80's - 90's, had many Chaos, Tipo's, Escape's, LA-1,Dash-5, Speeda, and probably missing one or two.. but seems like a life time ago now. This was my Dad's motor, as I ran the OS abc pumped motors mainly.

I do know we generally ran 11x10 at the smallest back then, and more typically 11x11 11x12's, since 12" props were really getting into ground clearance on most our birds. AND we flew off pavement!

This 60 SS, for the half tank I ran the other day, had an amazingly crisp and responsive transision, once warmed and loosened up again. The needle was very sensitive, where 3-4 clicks rich from peak would really choke it. I do remember that about the YS, having a very definitive range on the needle. The plug survived, and is still burning hot, so lead me to believe the pipe length was close.
My only concern now, is how the gaskets and diaphram to the fuel meetering valve have held up over the years sitting, and where I can get them. I have not yet searched around much though.
I WILL need a gasket and bearing set for the 61 LS, and more than likely for the 60 SS, even though it is running, I cant hardly feel comfortable with the diaphram having sat in a box put away somewhat wet for what.. 15-18 years now. The head on it has a little pavement rash, nothing that effects the running, but would like to replace that too, just to make it nice again. However, the 60 SS really did not have a lot of run time. Maybe a season and a half.. 5 gallons, under 10 Id say, safely.
Thanks for all the input guys Had I known how much this stuff would bring the kid back out in me, i'd have dug it out several years ago!

*Oh, and am just running Cool Power 15%, being all I can get locally. If they prove themselves, I will see about getting some powermaster YS 20/20 from Chief.. I think they carry it, and its not far from home.

you can get the diaphragms for both from YSPerformance. I just bought one for my 60 and my 61AR. He also had bearings for the 61AR on the shelf aloing with a gasket set and Oring set. Give Richard a call, he should be able to hook you up.

Jeff,

YS Performance (www.ysperformance.com) used to be Dave Shadel's site. I believe that site is no longer active or live.

Are you referring to Rich Verano at YS Engines (www.ysengines.net)?

Cheers, David

Rich's site. They all run together in ny brain. I bought parts from him in March.

I believe this is the place you were lrefering too. www.ysengines.net

-

Bryan

That is the one site I have as well, besides Central Hobbies. Although they only list 4 stroke motors for parts. I imagine if a guy called them they could also help out. I might try them when I am ready for the parts, since there is ALWAYS something from Central you just have to have

I've had good results dealing with YS direct. If you know the part #'s you need, you can send them a note and ask via email
if they're still available. Good chance they are.
I've gotten parts / gaskets / diaphragm for a YS .45 from them direct. I also have a .61 LS and have a parts list for it.

Don't remember where I found the parts list or op manual for it, so I can't supply a link for that. But here's a link for ordering parts from Japan direct if it helps. They'll
reply to you within a day or two after sending it and let you know if they're still available.

https://www.mmjp.or.jp/ssl.yspower.co.jp/order_e.html