airraptor

My Feedback: (66)

I don't do much maintenance on these at all. I adjust valves a couple of times when new and have never taken one apart just to clean the exhaust valve (maybe I should) but have taken them apart to clean top of piston but this isn't because of poor running. I like the piston tops to have a mirror finish but someday will ceramic coat them to play around with coatings. The YS 80 use the same piston from the 70 use stroke the crank 3mm. The 80 is a power house and is about 200 more than the DZ70. I have the stuff to make a DZ80 just have to find the time.
For glow plugs I just use the OS/YS F plug as they are pretty durable. If your four stroke is side mounted or upright you don't need a four stroke plug. you can play around with super cold to super hot plugs for your nitro and use and see how they do. I wish I had the time to play around with different plugs.
I won't assume but pretty sure everyone in my area and everyone racing is running full synthetic at 20% oil. I know one guy is running less but he wont say how much lol He also has more lean runs than everyone else too.

As far as the YS63 I dont have much experience with it so I cant say much on it. I do know Richard and I will ask him about it and the use of high nitro.

Four Stroker

"The YS 80 use the same piston from the 70" - NOPE, not mine. That is what the instructions say but not true. I have two 70's. They have a flat top long skirt piston. The 80 piston is dished out / bored 10~20 thou and the height is maybe 3 mm shorter than the 70. Yours may be different. I got mine from Central Hobbies. The other error in the instructions is the cylinder to crank case seal is NOT the gasket YS5015 but a roughly 1 x 30 ID O-ring. YS lists this as G7008 and say it is for the 80 cdi.

The YS 80S is a beast considering that it is the same case as the original 53 ! Yamada tells me that the HP peak is at 15,000 rpm. I am sure it puts out a wad of HP and wish Peter Chinn was still around and would dyno test the YS 80 vs. Saito 82. But I read a review that the Saito 82 has a HP peak at 9,000 rpm (cam profile and timing ?) so it's not really a fair comparison.

By the way, what valve clearance do you use for racing ?

Rotor Rage 30% is 21% full synthetic oil. I don't think fuel is a problem. The CY 30% runs well also.

airraptor

My Feedback: (66)

Ha ok maybe they changed them some. I had one of the prototype ones lol. I have two more in the box and I should go look. I did look at the manuals and they show the same part numbers for the pistons but shows different rods. I will look at some and see later if I get some time. They made some DZ engines also so maybe those are different pistons. I do know that YS makes changes in their engines and for the better usually like gaskets and so on. They YS 80 will for sure beat the 82 and I think it would surpass the 91 and 100. I ran my 80 on a 14x7 and turned over 10,500 if I remember correctly. Tetsuo was running 15x7 props on the early 80 engines in Japan.
Tetsuo will be here for the NATS. Build you a plane and come race with us. The World Models Strega is a great warbird for racing as it was designed along with WM for warbird racing. You dont need to beef up anything on it.
The orange and whit plane is my WM strega I made into a Stiletto by changing the wing tips.

kenh3497

I've been running Sig Champion 15% nitro in my YS's without much issue. I do see a little more carbon build up than what some consider "normal". I'm aware of the carbon and schedule my maintenance accordingly. Currently I have a 63 with about 4 gallons of fuel through it. The 63 is pretty miserly on fuel usage so that is quite a bit of flying time. I'm not saying what I'm doing is right or wrong. It's just my experience with the engines and fuel. Once I start to run my 140DZ more, I may change my mind on fuel. Time will tell.

Ken

speedracerntrixie

My Feedback: (29)

I would have to agree with the Raptor here. I run the same series that he does and have also seen what he is claiming first hand. In order to get the WM airplanes to gold class break out speed here at sea level, a minimum of 50% nitro is needed. On slower courses such as Redding, 65% is what it takes. My first hand experience with this on my own airplane is here in Sacramento my Macchi runs in the 1:30-1:36 time slot with 30% nitro. In Readding I wasn't able to best 1:38 on 30%. Back here in Sacramento on 40% my airplane flew a 1:16. Big difference just between 30% and 40%, but I will agree that past 60% the power increase would not be worth the loss of reliability. After 3 seasons of racing with mostly 30% on all synthetic fuel, there was very little carbon build up on the exhaust valve during a recent tear down.If we did not do breakout racing then I do believe that 60%-65% nitro on the 115WS would be the norm.

airraptor

My Feedback: (66)

Speed, we had good weather in redding this last race. I was able to run 45% and break out I switched to 60% in one race and broke out with a 1:25.7 or something like that. Logan was running 35% like you would have. I think on the YS 115WS 70% would be a goof high limit and 75 needs about 5 or more turns out. But if everyone had a Macchi then could run much less. I am working on some props where we can run the number on 20%. The first batch will be all carbon tow hand layed up. I will get you a couple.

speedracerntrixie

My Feedback: (29)

Sweet, I will be ready to try some props soon. I sprayed the base coat on the new Macchi today. Colors and clear will be tomorrow. Then I will have to start breaking in the new top end I installed in the 115. Should be all ready for Nitro Madness.