drac1

My Feedback: (4)

It's getting too hot.

drac1

My Feedback: (4)

Not usually.

FBW

Mine does the same.........I think the O rings aren't up to spec !!!!!
The old O rings didn't do this.

naftali

I tried enriching the mixture, Viton O rings - all to no avail, it still sticks after one flight.
The spinner is cold upon landing, even in hot summer days.
A friend of mine is still using the old O ring - and no problem, so maybe the new ones are made from a different material.
Anyhow I ordered rubber and silicon 14x4 O rings and hope for the best.

drac1

My Feedback: (4)

I'm using the new YS O rings. I do think they are probably not quite as good as the Hatori ones, but I don't have problems with them sticking to the header unless they get too hot. This generally only happens if it is too lean.

The YS O rings seem to be a slightly different size. They fit tighter on the header.

I doubt normal rubber and Silicon will last very long in that environment. Let us know how it goes.

FBW

I have tried both Rubber and Silicon........the original Hatori are the best.
I am now using MOLYCOTE 3451 bearing grease to coat all O rings on the YS and so far so good.Time will tell.

drac1

My Feedback: (4)

It's a shame Hatori closed down, there stuff was extremely good. I have a couple Hatori O rings left, but I've been using the YS ones for a while now.

I'll have to the Molykote a go.

drac1

My Feedback: (4)

The one on the left is Hatori and the one on the right is YS. You can see the difference.

Hatori is 3.6mm section
YS is 4mm section

The Hatori is a loose fit on the header, around 1mm clearance. The muffler pushes onto the header quite easily.

The YS is a neat push fit onto the header, which explains why it is much harder to get the muffler on. Maybe it's a bit too tight? Being that tight, it wouldn't move on the header as much while flying and wouldn't get any oil under for lubrication as the Hatori does. Maybe not moving is causing it to stick?

Possibly the Molykote grease will let it move on the header and prevent it from sticking?

naftali

I ordered neoprene(NBR) and silicon O rings from ALIEXPRESS, 22x14 mm. SkyCable Store. First I tried the silicon, supposed to withstand 200 deg. C. It did not stick, but Wear and Tear were excessive after one flight only. As a last resort and nothing to lose feeling I installed the NBR, rated to 100 deg. C only. The best. Not sticking, not leaking for 30 flights, some droplets after 35. Pack of 10 units for 93 cents, postage one dollar more.

apereira

Have you guys tried the Viton O rings?

I changed the Hattori often but the YS not so often nor the Viton ones.

FBW

After 40 flights with Molycote no Oil leak .......

Pattern freak

My Feedback: (1)

Hi all, hope all is well! It has been very quiet on this YS thread lately, hopefully everyone is enjoying and flying! It has been a big learning curve on the cdi thing for me and slowly learning it, I took almost a 20 year break of flying and the last YS I flew in F3A was a 140 dingo in 2004, this 200s is a real beast of an engine and the power is something else, a completely new beast and nothing compared to the old 140 engines!

Something strange happened to me, had the engine on the stand and everything was good, engine had super compression and I was satisfied with how it was running so decided to put it on the plane, when unbolting the prop I heard a loud clicking sound and immediately compression was lost! I figured something broke in the engine and really was expecting the worse! I took off the prop and opened the valve cover to only see that the intake valve was stuck! I dropped some Klotz oil(KL200) and spun the prop and left it and came back and that was it! Compression came back and everything normal again but I noticed that the pushrod (pics) was kinda off of the screw as you can see in the pictures.

Is this a sign of a bend rod? Haven’t run the engine yet as I’m worried that It could be bend! The engine spins normal with super compression.

Greg

apereira

that’s not a problem, it happened during reasembly , just press the valve and get the rod in the correct place.

Pattern freak

My Feedback: (1)

Hi Alejandro thanks for the reply but It’s not the exhaust pushrod it’s the intake (regulator) small rod that is off! It’s not inline with the intake tappet screw as you can see it’s off to the left and forward of the screw or is it normal?

apereira

I am looking at it ln my phone sorry, I see what you mean, I am on a business trip so I can’t look at mine now, does the rocker has too much side play? But that’s the way the rod goes in the intake valve, it has a guide (the black plastic plug) so it doesn’t move out of place. You could loosen the rocker shaft and move it a bit towards the exhaust valve to better center the intake rocker over the pushrod, it think that can be done.

Pattern freak

My Feedback: (1)

No worries! There’s absolutely no play on the rocker shaft so I can not move the arm over the screw! I just see it strange as I recall not seeing the rod so off of the tappet screw! As you stated the rod goes in the plastic hub so it doesn’t move out of position, just want to know if it’s normal. Haven’t run the engine yet, the engine spins normal with tons of compression. I will open the valve cover of my 91AC and take a look at it to compare.

FBW

I think this is normal for the push rod to be offset ......mine is the same.
As for the stuck valve this happens from time to time.I had one recently in flight where the engine lost power but kept running and I managed to land safely.
I have new lifters on order from YS. I think the lifters are the issue of the valve getting stuck.

Pattern freak

My Feedback: (1)

it’s good to know, thanks for the feedback! so looks like this is normal for it to be offset from the tappet screw! It’s kinda odd as I never put attention and didn’t notice that it was so off, it’s kinda scary but it can’t move out of position as the plastic guide won’t let it! Will definitely keep an eye on the lifters! I will start the engine this weekend and see how it goes!

bjr_93tz

Well, that little storage experiment ended in a stinking mess of putrid oil residue and corrosion.
I knew I wasn't going to be using this engine for a while, so I ran 1/4 tank of 0% nitro, 10% coolpower purple and 10% maxima castor 927 on the bench before putting it away in my spare room. A little over two years later and woweeee, I've almost enough iron oxide in there to kick off a thermite burn. Oddly enough, an old bearing I put in an aerosol lid and 1/2 submerged with same fuel mix and put on the shelf in my shed at the same time is in the same condition I left it. The methanol evaporated out and the oil left behind has turned to black sludge, but the bearing is fine.

I've cleaned up most of the parts now and have them in a little bag with some light machine oil, but I'm seriously considering if I should reassemble this engine and put it away, or box it up as jigsaw puzzle with the required new parts so that if I ever want to use it again, I can just reassemble it and go flying?

As an aside, I bought a heli a while back with OS105HZ-R which came with a few litres of old fuel containing Klotz KL198 oil (I'd never used Klotz oil before). I'm about 130 litres into a back-to-back oil test after running 80 litres of my usual coolpower brew through it (2 rear bearings), I'm now at about 50 litres (rear bearing still feels good) of the KL198 brew and I like the KL198. For reference, in the heli 40 litres is about 11 hours run time at 16k rpm.


Not a good start.

As expected.

lots of rust.

Even more rust, badly pitted

Cleaned up with new valve springs.

naftali

First step in the storage procedure is running the engine dry.
Then lubricate all moving parts with YS After Run oil.
Turn the engine over several times to insure protection.