It's getting too hot.

Not usually.

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

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.

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.

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.

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.

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?

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.

Have you guys tried the Viton O rings?

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

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

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

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

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?

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.

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.

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.

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!

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.

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.

When will I ever learn?????
Being the forever optimist, not long after that post in November 2023 I decided to put that jigsaw puzzle back together and leave it off to one side while also deciding to order a brand new throttle body assemble along with some other bits and bobs.

Since then I've mainly been flying heli's as a (permanent?) break from F3A and been enjoying pouring fuel into my OS105HZ-R, which I'm now up to about 220 litres (58US gal) without a deadstick or running issue, only only replacing normal wear and tear items.

So towards the end of two weeks leave from work I decided to put that new throttle body on the 200cdi and give it a run as I haven't flown the Aries 07 for a long time. So I did the carb swap, took it to the field and it was a bit cranky to start but after I got it going and messed with the needle a bit I let 1/2 tank run though it and though I'd give it a flight. During that ground fiddling I noticed the needle valve getting a bit wet and a bit of pink (now running Klotz KL-198 oil) fluid forming drops off a few parts. I put up two tanks through it in that air just general flying as the engine really is still "new" and each time had to wipe out a pool of raw fuel in the bellypan. Day one partly successful, engine worked ok but something's not right?

Morning of day two, pull the engine and go over everything checking for leaks, double check the usual suspects and generally waste another few hours spinning spanners on this piece of fecal matter. Wash it thoroughly in methanol and dry it off so it's completely "dry" outside, remount it, fuel it up and run it for about 5 seconds and check if anything is getting wet. Well yes wet it was getting. Just the tiniest bit of reflective glare coming off from where the needle vale body bolts on to the cab body. Quick wipe, a 15-20 second motor run and it's dripping fuel again but at least I know that fuel is not coming from anywhere else.

So I block the injector line and pressurise the fuel supply to the throttle body and fuel starts running out from around the carb barrel. A brand new throttle body I bough 18 months ago to replace the one I had been bodgying up trying to get it working right. The video is just air and a bit of soapy water but you get the idea. The seal can't be perfect but it shouldn't be leaking fuel either.

I've had bad YS parts right out of the box including a cdi sensor that worked at hand crank speed but not at starter speed(???) but my luck with this DZ200cdi is something special. Now it's been run, I have to pull this engine again and flush it for proper storage. I've got a sweaty body part that YS can apply some vacuum to with their mouth right about now....

Edit: Sometimes it's good to vent. Replaced the o-ring on the barrel and no more leaking,,,,to the outside at least. The cynic in me is guessing it's leaking that fuel into the motor on the non-o-ring side now. Weather is bad today and club has an ANZAC day event on Friday so Saturday afternoon might be the earliest I can give it a proper run. Fingers Crossed!!

Hey Brett,

I was just going to say I reckon it's the O ring, there's nothing else it can be. As an aside, I very, very rarely replace that O ring. Just every now and then if I think of it and can be bothered taking the barrel out 🙄 Never had a leak there though.

Not sure what you mean by leaking into the engine on the non O ring side?

The only barrel issues I've had is an incorrectly machined one. It wouldn't throttle up at all, was very rough in the mid range and wouldn't throttle through.
Oh and the pesky bottom right carb housing mounting lug breaking, which has only happened on my 200's, no other engines. Over stressed maybe 🤔 I've had half a dozen break, but I've got that sorted now 😬
Back plates used to be problematic as well. The wire would break at the hard joint. I had a few of those in the early days, but have that sorted as well. Haven't replaced a back plate in around 8 years now.

A couple of things:
Sounds like a too rich problem.
Is the break in needle open?
Breaking in doesn't need to be prolonged. I run 3 tanks (330cc) through on the test stand at rich settings, then gradually lean it during the 4th ending up at the tune for normal flying.
Put it in the plane and fine tune as required.

Looking forward to hearing how you go. More than happy to take a look if it's still not right 🙂

Thanks for the offer Scott.
In a world of perfect clearance, all the fuel should stay in that tapered slot, then follow the deep groove around to the outlet on the other side which goes up to the injector. I figure if there's enough clearance so that fuel is happy to leak out of that slot in the direction of the red arrow only to be stopped by an o-ring (not fitted in the picture), then it would be equally happy to leak out of the slot in the direction of the green arrow into the crankcase.

I'm almost hesitant to report on this afternoon's flying session for fear of jinxing something.

The engine seemed to respond predictably to pump and needle adjustments and I put through about 2 litres of fuel across 4 flights consisting mainly of sport flying with cuban eights, humpty bumps, loops, rolls, double Immelmann's etc and it just seemed to work without any fussing and was still externally "dry". I've been burned before so I'm not declaring it "fixed" until I can't remember how much fuel I've mixed for it and I've forgotten where the needle is set.

It was good to get the Aries 07 out for a few laps today but for an airframe that was designed around a 17x13 and still worked nice on an 19x11 with a DZ170cdi, The airframe feels a bit over-propped with a DZ200cdi swinging a 21.5x10.5. Fantastic vertical though

Hi Brett,

I think it's fair to assume there is some fuel going inwards along the direction of the green arrow, but it would just end up going up the intake tube and into the cylinder. I doubt it's much and any effect it may have, would be taken care of by tuning.

Good to hear it went well today and hopefully it will continue that way.

Ground clearance does become an issue with the 2000 era planes, but that's what they make longer legs for 😁 As they say, you can never have enough power 😂

Agree re sloppy barrel/throttle body fits and I followed previous posts and your own by fitting O rings to the barrel.
Seemingly you've abandoned that system - ??
Using KL198 oil ??
I mix (by weight - saves a lot of messing about) 14% KL200 and 23% nitromethane - also suits DZ115.