SeaJay

My Feedback: (6)

Just thought of something else..

Since I will be dismantling the engine, I think I will add a Bowman Ring to the engine.. should make this powerhouse even stronger..

anyone know where I can get a "Blow Up View" of these engines, I would like to know what I am getting myself into, prior to the tear down!

Thanks again, Craig.

drac1

My Feedback: (4)

Central Hobbies have manuals on their web site.

Remember google is your friend. Lol.

SeaJay

My Feedback: (6)

Yes Sir, you are correct on that!

Thanks for the info on the manual locations on the Web, saved me the extra searching!!

Craig..

blw

My Feedback: (3)

SeaJay,

Why not replace the banged up piston while you have engine on the bench?

airraptor

My Feedback: (66)

YS-115WS, DZ-70 and 91AC.

SeaJay

My Feedback: (6)

BLW,

Well, the piston is right at $80 and that's a bit steep for me at the moment.. I was just hoping that I could get the engine running on the in-expensive side for now, otherwise will have to put it on the shelf until my financial situation makes a U-Turn!

I had another engine that I put on the Airframe that this engine came off of, but I also have an ARF that I could put together, and put this engine on it, but it is not a necessity, as I have several other planes ready to fly!

Craig.

Daniel-EL

My Feedback: (9)

I have an original YS 120 that ran fine for the first season I had it, then never ran again. I'v replaced all the usual parts, glow plugs, pump diaphram, fuel lines, filters and check valve....still doesn't run. I gave up, put it back in the box, and got out my trusty, but admittedly less powerful OS'. I just don't have the patience to tinker with it incessantly. Reminds me of my uncle's Jaguar XKE - beautiful and powerful, but required constant tinkering.

drac1

My Feedback: (4)

I have had 14 YS's from the FZ63 to my current 185cdi's, of which i still have 12. I never tinker. Set and forget.

As with everything you get the occasional problem, but mostly it is fly, fly, fly.

bogbeagle

If you get tired of fiddling with your troublesome YS, you can easily convert it normal aspiration.

Mine is now amongst the best engines that I own.

Yes, it produces much less power ... but, I'm running straight fuel ... and it is super-reliable.


http://www.youtube.com/watch?v=ypPmVluBT_g&list=UU4HLk42VM0CCjglQ2KPcYdA&feature=c4-overview

blw

My Feedback: (3)

Craig, I know what you mean. I didn't know the price though.

SeaJay

My Feedback: (6)

BLW,

With that little extra piece of info, would you go ahead and put it back together and fly it, or just shelf it for now?? Whadda ya think?

I was just wondering if anyone else has had similar experiences and what the outcome had been.. My only real concern is, would these dents actually cause Hot Spots on the pistons, and possibly have a melt through in the piston, potentially causing damage to more than just the piston, making repairs even more expensive..

Craig.

drac1

My Feedback: (4)

I would fit the new head and fly it.

My 175cdi Broke a tooth of the cam gear and the piston hit the valve denting the piston. New cam and flew. No problems.

bigbuster

My Feedback: (12)

Seajay, I know little about hot spots, but I did a search and there is lots in the automotive racing sector on this, some mention thermal coating the crown. Do a search and check it out, it's free..

GallopingGhostler

Does the auto industry engine scenario of special racing gasoline, running engines near red line with water cooling duplicate our model engine scenario of glow fuel and use? I'd think our model aeroplane engines run more like car engines in every day traffic, flying stunt and pattern, revving up and down and don't run at red line. Also, gasoline has a much higher flame temperature than glow. Seems more of an apple to oranges comparison, sounds great in theory, but I'd think it may not apply because the operating parameters are different.

Hobbsy

My Feedback: (102)

Craig, that piston looks great compared to the one in my SuperTigre 4500. At some point in it's life, before Dave, it ate both of its circlips. The piston top has about a hundred dents in it, and grooves in the sides. Bob Davis of Davis Diesel told me to just use a jewelers file, clean up the ring grooves and use it. It is fine. If you don't see any cracks under the piston it should be good to go.

SeaJay

My Feedback: (6)

Hobbsy,

Nope, no cracks can be seen above or below the piston. Although I believe that I can see a small dent in the bottom side of the piston, it is so small though that I am not sure if it's a dent, or just a discoloration caused by tarnish. The overwhelming opinion is "Run what U Brung" so that's what I am going to do! Besides, I don't believe that I have ever heard of a piston having Melt/Burn through of any glow powered engine.

Thank you to all for the input.

Craig.

blw

My Feedback: (3)

I'd try it if it were mine. You got lucky with the liner not being damaged.

Hemikiller

My Feedback: (125)

I'd run it, you have nothing to lose at this point and it if it has detonation issues, you can just change the piston later.

SeaJay

My Feedback: (6)

Absolutely, that is what I am going to do, new ring, re-assemble and run!!

Learned something new about the YS 4 stroke engines today as to how finicky they can be, one of the flyers at the field had several dead sticks with his fz140 today, he checked all his plumbing, several times, then finally decided One last try with a brand new glow plug.... well, there was the problem! he had several great flights, no more dead sticks.

Craig.

drac1

My Feedback: (4)

That's not a YS being finicky. Nothing will run with a worn out plug.
This is how most of the rubbish about how difficult and unreliable YS' s are starts.
I very rarely change plugs. When I do I can,'t remember the last time I did.

SeaJay

My Feedback: (6)

Ok, Question then.. And I am not being a Smarty Pants, I am honestly curious!

How is it that a plug can still glow, but be worn out?? I think I remember something about some kind of reaction between the filament itself and the fuel?? But I always figured that if it glows, it is still good! I have never thrown away a plug that still glows, I keep them, and re-use them in other engines as they need them!

Craig.

hairy46

My Feedback: (1)

I have bought a 120 and a 140, have not broke eather in yet but have to now, have a warbird that needs an engine, anything I should know on the break in?

drac1

My Feedback: (4)

Plugs have Platinum on the element which reacts with the methanol. The Platinum reduces over time.
While the glow driver is connected they will glow, but when the Platinum content gets too low it can't produce a sufficient reaction to ignite the fuel.
An indication of a bad plug is a drop in rpm when the glow is removed.

GallopingGhostler

That platinum stability seems to vary between plug manufacturers. I had a 20 year old low usage Swanson Associates Fireball hot plug left in an old engine that wasn't worth a hoot. Engine would cut out on me repeatedly in a random unpredictable fashion. Replacing it restored the reliability. Yet, an old decrepit Enya #30 plug from a used 1966 version Enya E-Bay buy still works like a charm.

Haven't had trouble with the old Fireball plugs still new in the package. I guess that some plugs that get coated with glow fuel causes that platinum plating on the nichrome wire element to degrade with time.

drac1

My Feedback: (4)

Yeah. There are plugs and there are plugs. I use the OS F plug in my YS's.