YS engine problems.

[jwooten]

I got my glow heli out while I am waiting for some electric parts. That little miss in the YS 91 engine that I could not tune out has turned into pre-detonation with the warmer weather. I tried changing from an Enya #8 glowplug to an OS A3. This helped but did not eliminate the problem. The problem is worse at lower RPM (1500 headspeed) than it is at higher RPM (1800 headspeed).

This is in a Predator with a YS 91 and MPII, 8.18 gear ratio and Coolpower 30% heli fuel.

Any suggestions on what to start changing first?

Jimmy

[bighands3d]

I have been using the enya 3 and haven't had any problems but will be going to the viper head or wait till the new YS with the red head. comes out.

I see you guys went to dothan this past weekend we went to BS..

[jwooten]

I expect the trouble is with the Muscle pipe. The Hatori is the preferred pipe according to the “experts”. I may just have one with on unusually tight head.

Let’s see what Harkey has to say about this.

Jimmy

[DavidH]

I have never used the MPII pipe. Always used the Hatori mufflers. On the YS 91 I used CP 30%, 8.18 ratio, SB 16 Hatori. Enya 3 plug. The motor ran nicely. Also installed the Viperhead and used two OS 8s, two Enya 3's, and Enya 3 and 4 combo. It also ran good with those combinations. Don't know why the motor would be detonating even with the MPII installed. Should be easy enough to check if it is the pipe. See if you can borrow a Hatori from someone and try it.

David

[jwooten]

I thought you had all the answers. I will see what I can come up with. It hink glow fuel just doesn't like me. I may just need another shim in the head.

Jimmy

[conrod]

If you have a govenor, turn it off.
Also try richening it up some to the point of too rich. See what happens. If it goes away, then progressively lean in small increments until satisfied.
What are your needle settings??
Conrad

[jwooten]

Conrad,

It has been so rich that youy can hardly get it to spool up and still has the ping and miss. The cooler plug helped. I will have to check and see what the current settings are. Bill Meader was helping me this. Lots of smoke and sounds like it is lean.

Jimmy

[Greg McFadden]

you might also check to see if the diaphram is ok, one of the locals had some really strange problems with his and it turned out to be a defective diaphram.

[zak johns]

JWooten,
I have always ran the enya 3. I would not use a A3.

[DavidH]

Jimmy,
Does the tank have pressure on it when you shut the engine off?

The check valves will gum up and not work properly if the heli has been sitting for a while. Take the check valve apart and let it soak in some rubbing alcohol. Then put it back together, it is only the two halves , a spring and a diaphragm.

If the colder plug made a difference in the detonation problem, it sounds like it may not be getting enough fuel. Might try taking the regulator off and cleaning it also. The YS's are great engines, but they do not take well to sitting around for long periods and not being used unless they were prepared for it. There is some small orfices in the carb that could be paritally blocked also.

The YS is really not particular which plug is used. I have used a K&B 1L in them and it ran the same as when I used the Enya 3.

David

[jwooten]

The tank has the normal pressure on it.
The needle valve settings are: high 1.75, medium 1.5, low 1.5.
It was pinging at a richer setting.
It sounds rich and behaves rich. The smoke is very heavy.
I think it is getting enough fuel. Is it getting consistent fuel?

Old fuel??

Jimmy

[jwooten]

Zak,

I should not have to use the A3. This tells me something is wrong.

Jimmy

[DanW]

Jimmy,

If you happen to be up this way this weekend I'll be glad to help you look at it. I think we should be able to figure it out. Those needle settings seem on the rich side to me.

Dan

[jwooten]

Dan, The needles are very rich. Something besides simple adjustments is wrong. I have checked the bearings, and they are fine.

I will be cleaning up storm damage Saturday. I might be able to play Sunday.

Jimmy

[DavidH]

Old fuel?

That could also be the problem. I know you have been messing the E models for a while. How long has the fuel been sitting ?
The needle settings you posted are way rich.
Normally with 30% CP the needle settings are
High ( short needle) 3/4 to 1 turn
Mid ( Long needle) 1 3/8 to 1 3/4 open
Low ( needle in carb barrel) about 1 1/2 or producing nice idle and transistion.

the low needle does affect the mid range needle and the mid range needle does affect the high range needle.


Try some fuel that you know is fresh first before you do anything else.
David

[Greg McFadden]

"needles very rich" definately check the diaphram. (I should have said this earlier, but I was in a hurry). one of our locals had a problem where he could not get the needles rich enough. The needles were almost falling out and still the engine behaved lean. First we thought bad fuel, we tried some of mine, no go. He finally sent it into YS and they replied back that the diaphram was defective and not metering in the proper amount of fuel (hence the absurd needle settings but still lean).

[big-al]

The diaphram may be the problem. I think I've got a spare one for the YS and you're welcome to try it.

[jwooten]

That fuel is about 1 year old unopened. I do have some new fuel. I will try that before I take the motor out (pita). Now that I fly electric, I always win a gallon of fuel at funflys :)

Jimmy

[jwooten]

I wasn't fuel. I will get with Dan this weekend (I hope) to get another ear on it.

Jimmy

[Rodney]

This may sound dumb but check the crank bearing, maybe what you are hearing is not detonation.

[jwooten]

The bearing were the first thing I checked. With my hearing, there is not telling what I here. While hovering the other day, the engine started running much faster and smother. I think a complete teardown and cleaning is in order. I just wish it wasn't so hard to get the engine out of the Predator.

Jimmy

[conrod]

let us know how it goes. Dan W. knows his YS's :)

[jwooten]

Conrad, You need to get up here sometimes.

The engine is now running correctly. I guess it had some trash in it. I will do a complete cleaning over the holidays.

Jimmy

[conrod]

Wish I could!

[nando v. arnhem]

Hi guys,

almost of you fly with 30% nitro. Many of you use a OS 8 (and Enya 3)plug. The OS 8 is made for a low percentage nitro (5-15%). when you burn 30% nitro,
and use the 8 plug, than inflamed the 8 plug too quick. the conseque is that your bearings in your motor break down. The OS 8 plug is too hot for 30% nitro. You can better use the A5 plug, he is colder and inflamed later.

So, use you under 15% nitro, the OS8 and Enya 3 is very good
use you more than 15% nitro, the OS A5 is better.

I use 30% nitro too (for my Raptor 50 and 90), I have tried both plugs and i find the A5 better. I have more power and the motor runs stationairy very better than i use the 8 plug.

I wish you good luck,
nando van arnhem