140DZ

140DZ
View related threads: (in this forum | in all forums)

Logged in as Guest

Users viewing this topic: none

Printable Version

All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Manufacturers Direct Support Forum >> YS Engines Support >> 140DZ

Page: [1] 2 next > >>

Login

Message

<< Older Topic Newer Topic >>

140DZ - 6/14/2007 4:24:56 AM

Posts: 60
Joined: 1/26/2003
From: Wyandotte, MI, USA
Status: offline

OK, I'm getting frustrated with this one . . . I just picked up used 140DZ. The thing is not running right in the midrange, and seem slightly down on power (8800RPM with a Mejzlik 16X12 on Powermaster 30% DZ blend). Compared to my great running 160DZ, the 140 seems vague on high speed needle setting. Mine will run about the same at full throttle anywhere from 1-3/4 to 1-1/3 turns out. The idle is solid, but the midrange is soggy, and it has quit 3 times in the air at part throttle, the latest tonight on the second 45 line of a reverse cuban.

I ran it on the ground, and noticed there a lot of bubbles in the injector line at part throttle. Maybe the pump is bad?

_____________________________

Mrs. Kane`s Husband

RE: 140DZ - 6/14/2007 4:38:15 AM

Posts: 2429
Joined: 12/30/2001
From: Goodyear, AZ, USA
Status: offline

The 140DZ has a very broad HS needle as you said. You should run it toward the leaner side of the range...maybe 1-1/3 to 1.5 open. If its rich in the middle then you can lean the pump slightly. Say 1/8th turn CCW on the pump screw.

I don't know that its a bad pump.

Turning a 16-12 at 8800 on 30% DZ fuel not down on power. I used the APC 16-12 at it turned about 8600-8800 on 30% heli. So you are in the right range.

If your pump was bad it would not idle well.

It could be cutting in the air from too rich....also when was the last time you changed the plug?
This can show similar problems. rich mid rnage and dead sticks....

Change the plug first then look to leaning the pump a little. If it gets detonation in the middle and gets that hollow sound then cut it off and richen the pump back up.

Troy Newman
Team YS

(in reply to getterflash)

RE: 140DZ - 6/14/2007 5:16:50 AM

Posts: 60
Joined: 1/26/2003
From: Wyandotte, MI, USA
Status: offline

The plug is a new OS-F, I put it in after it quit for the second time at the D4-D5 shootout. D5 DZ wizard JH worked on it Saturday night, It ran like a monster on Sunday, HS needle out 1-3/4. I went out tonight to practice (lord knows I need it) set the same as it was for rounds 5 and 6 in Muncie and it quit on the opening reverse cuban 8 in Masters. I tried setting the HS needle but it seemed to have no effect on midrange. There is slight stumble going from idle to full throttle, I figured the pump was lean, but richening it did not help the midrange.

I miss my 160DZ. My home field is not kind to unexpected dead stick landings.

_____________________________

Mrs. Kane`s Husband

(in reply to Troy Newman)

RE: 140DZ - 6/14/2007 5:50:08 AM

Posts: 2429
Joined: 12/30/2001
From: Goodyear, AZ, USA
Status: offline

why didn't you grab me at the Shootout and I could have helped. Its very hard to help via the internet....yet I was there. I was screwing around with the boys and not really paying close attension to other guys flying. I know Bob Kane had lots of problems. I offered him a well tested and run 160DZ that was sitting in the box all weekend long. Instead he fought through several dead sticks. I offered the motor each time and he refused each time.

In any case as I said above the HS needle on the 140's is pretty broad and it will show the little to no change that you are talking about. As I said above THIS IS NORMAL. The HS will have little affect on the midrange to your ear...but it can if too rich on the HS cause the engien to load up and die in the mid-range. The HS needle works at all the settings not just the top end. This is why you should run in the leaner spot of that wide band you mentioned.

Also I mentioned above that you should lean the pump. The fact that you richened it and it didn't help is a sign it could have been rich to begin with.

I think you should lean the pump. CW about 1/4 turn and see if the midrange cleans up. This is what the pump does it controls the idle and transition though the mid range. So if you say its slobbery in the mid range then the pump is currently too rich.

Troy Newman
Team YS

(in reply to getterflash)

RE: 140DZ - 6/14/2007 1:09:54 PM

XMANS

Posts: 91
Joined: 8/8/2004
From: HOPPERS CROSSING VICTORIA, AUSTRALIA
Status: offline

Hi Troy,

I have found that bubbles in the injector line can mean a worn plunger in the pump, and its easy to test
if this is the case.

First remove the pump assembly from the engine complete with the two half push rods,
Get two pices of fuel tubing of sufficent length with a clunk attached to one end of each piece
and attach the other end of the tubing to the pump fittings.
Have two containers with some fuel in each container and drop the end with the clunk attached in each container.

Holding the pump assembly in one hand, and with the other hand hold the push rods between thumb and finger,
move the push rods up and down in the pump as fast as you can, the pump will start pumping fuel from one container to the other.
You may have to manually fill the lines and pump with fuel if it won't self prime.

While you are pumping fuel watch the fuel lines.
If the plunger is in good condition there will be no air bubbles in the fuel lines, if there are bubbles in the out side of the pump, then the plunger, and or, pump body is worn.
If you have bubbles on the in side to the pump then you have not set up the test properly.
I've found its usually only the plunger thats worn, and a new plunger is very cheap.

Reasemble the engine and test run, no bubbles in the injector line.

Team Crossman

(in reply to Troy Newman)

RE: 140DZ - 6/14/2007 6:20:10 PM

Posts: 2429
Joined: 12/30/2001
From: Goodyear, AZ, USA
Status: offline

Good Tip thanks.

I now that a sign of a bad pump is poor idle. It idles fine then unpredictably just shuts off. Not a hard thump just it can idle for 3 mins solid and then just no warning cuts off. Then it doesn't want to start. Let it cool and set for several minutes and it starts up and runs again like a champ and then out of nowhere just zip its off and won't start back up.

I have only had one pump go bad in my time with the DZ engines and that was many years ago. In fact I believe it was my first proto type 140DZ.

I have a pump here that I swapped out with a guy a couple years ago that we thought was bad at the time. Pump from my Backup engine and his problem were solved. I guess its time to play with it and find out why its bad.

Troy Newman
Team YS

(in reply to XMANS)

RE: 140DZ - 6/14/2007 6:30:31 PM

Posts: 60
Joined: 1/26/2003
From: Wyandotte, MI, USA
Status: offline

Troy, I just realized my real name is nowhere on the post, this is Bob Kane. Here is my brief history of this motor:

- Purchased from MA, fellow FAI pilot at Muncie. He said the motor had not been run since return from YS service.
- I installed it in the plane and ran it briefly Friday night. It ran ok, but there was a little fuel residue in the valve cover.
- Saturday morning, you suggested I change out the dark blue tubing on the motor with fresh fuel tubing. I did, and assumed that must
have been the source of the leak.
- The motor quit after 3 or 4 manuvers in my first round. When I got the plane back to the pits, the top of the motor was wet. I pulled the valve cover and found the gasket was cut. I put in a new gasket and assumed the problem was fixed.
- Motor ran ok for round 2
- Motor quit again a couple of manuvers into round 3. I did not die suddenly, it kind of coasted to a stop, always after low throttle
setting.
- I missed round 4, I could not get it tuned correctly.
- JH worked on the motor, and found the intake valve setting to be too tight, so the assumption was it was heating up during flight and
causing a loss of compression, consistant with the way it was quitting.
- JH also replaced the regulator diaphram with the newest version.I installed a new OS F plug.
- Reset the regulator to flush and needle out 1-3/4 turns, the thing ran great. Nice linear throttle, good power.
- Motor ran great for rounds 5 and 6

Which brings us to yesterday.

I am going to replace the pump body and upper pushrod to see if they are the source of the leak. I'll post the results.

_____________________________

Mrs. Kane`s Husband

(in reply to XMANS)

RE: 140DZ - 6/14/2007 6:59:47 PM

Posts: 2429
Joined: 12/30/2001
From: Goodyear, AZ, USA
Status: offline

Ok...that makes more sense. I really didn't see anyone having torubles but I know yours did. Every time it seemed you found the problema nd it should have been fixed.

Little things like a cut valve cover gasket and so on...

Another thing to consider is cooling. It was fairly mild in Muncie yet if it was Hot when you got back home it could be a cooling issue. The coasting to a stop on throttle up is sometimes a sign of over heating.

The tempattion you have is probably good as far as coolign goes. Just make sure raw air is hitting the pump. Some folks have lined their cowl with foam from the YS engine box. The cut out basically ducting to direct air flow right onto the engine. The YS engine box foam is so good for this as it is light...and if the engine hits it not damage will come to either part.

As temps heat up you may want to look at this if you have trouble with heating. A buddy down in Georgia Bryan Kennedy had some problems with a 140Sport and 140L this spring with over heating and we thought the motors were bad. Turns out he was just flying on 90 deg days with high humidity. I know how the rest of the country gets with the humid weather. Its tough on engines. Here in Phoenix witht he temp today at about 110deg I know what temp problems look like. I would say in Muncie it was probably the best weather I have seen there on the weeend. Sunday night we stayed and flew till dark. The air was so awesome. Rusty and I were practicing the Finals sequence and unknowns.

Troy

(in reply to getterflash)

RE: 140DZ - 6/14/2007 9:55:59 PM

Posts: 94
Joined: 8/6/2006
From: Barnstaple, UNITED KINGDOM
Status: offline

Troy.

I hate to but into a thread but my 140-sport seems to have some of these symptoms too.

Sometimes it will appear to coast to a stop and sometimes it will stop rather abruptly too. There is air bubbles in the fuel line from the regulator to carb line and because the motor is inverted the clyinder head and valve cover are wet with fuel from carb I think.
I too am getting rather perplexed with the motor , and, where I fly here in the UK no-one else has a YS so can't help with tuning it either.
It has good rapid transition from idle to full power and is taching at 8700 on a 17x6 apc prop and 20% MT Yamada fuel.
The idle needle is almost all the way out and yet the idle is rich and will choke up after 45 sec to 1 min.

Any light to shed on it !!!

(in reply to Troy Newman)

RE: 140DZ - 6/15/2007 12:01:31 AM

Posts: 2429
Joined: 12/30/2001
From: Goodyear, AZ, USA
Status: offline

Aeroboy the 140 Sport and the 140DZ are totally different animals. The way the engines work is totally different. So the problems are not the same although the symptoms could be similar.

On your 140 Sport...The low end air bleed screw if it is open more than about 2.5 turns its not doing anything. In fact this may be where you leak of fuel is coming from. The idle screw you are referring to only controls the size of the hole in the throttle barrel for air bleed. If the hole is full open it doesn't matter how many more turns you twist the screw open the hole is only one size max. If the adjustment is such that the hole is not big enough then the regulator is too rich and needs to be leaned out.

It could also be spitting from the carb if the regulator is set too rich.

If you lean the regulator a little it will be the air bleed screw back into a working range. Say 1/4 turn in CW on the regulator screw should get it closer.

It is common on the pressurized motors to have tiny bubbles in the line from the regulator to the carb. The reason is the fuel before the regulator is under pressure and when it goes to the carb it is allowed to expand, and doesn't sit under as much pressure. This means any tiny tiny tiny bubble will expand in volume.

Lean you regulator out a bit and try it. This should help the load up on idle.

Troy Newman
Team YS

(in reply to aeroboy1293)

RE: 140DZ - 6/17/2007 3:05:14 AM

Posts: 60
Joined: 1/26/2003
From: Wyandotte, MI, USA
Status: offline

I picked up some new pump parts, Central was back ordered on the pump body. That pump plunger looks an awful lot like the cam follower. I'm replacing the pump plunger, upper pushrod, carb O ring, and pump seal. The pump diaphragm was already replaced. The new parts will be installed tomorrow, I'll report the results.

_____________________________

Mrs. Kane`s Husband

(in reply to Troy Newman)

RE: 140DZ - 6/18/2007 2:19:48 AM

Posts: 60
Joined: 1/26/2003
From: Wyandotte, MI, USA
Status: offline

Well, no good. The engine ran strong and idled well, but a couple of manuevers into the Masters sequence it died. When it quits it is usually after some idling on a downline, the prop is still turning, it just won't throttle up and dies. On the ground the motor just does not sound right in the midrange. The RPMs will sometimes vary with no change in throttle position. I started with the pump regulator flush, but the motor hesitated going from idle to full throttle, and it would vary in RPM in the midrange, suggesting it was lean. I tried turning in the screw in 1/8 turn increments until it was too rich in the midrange, all to no avail.

When I first flew this plane last season, I was flying a 140DZ I bought from Tim Jesky, Andrew's alpha motor before he went electric. It was fresh from YS service. It behaved exactly the same way. I tried a lot of different remedies including a header tank, running it lean, playing with the regulator, all to no avail. The crank failed and that is when I purchased a new 160DZ, which ran like a clock once I got good pump for it. (When new it would blow the fuel line off the throttle body, the regulator was stuck closed. The bore of the regulator body was not machined properly).

The 160 ran great in this same airplane until the rotory valve failed a couple of weeks ago. I doubt the problem is related to the tank or cooling.

These motor are relatively simple. No adjustment except main needle and the pump regulator. My guess is something is wrong with the pump, but I have not figured out what yet. I am suspicious of the bubbles I see in the line going to the injector at part throttle. I also don't trust bench running. The motor will run all day long on the bench, as would my 160DZ with the bad regulator housing.

To summarize what was changed:

Pump Plunger
Pump regulator diaphram
Upper intake pushrod
Throttle Barrel O-Ring
Cleaned up Valve cover gasket surface
Leak Free gasket on valve cover
New intake valve adjuster (original was stripped)
New OS-F plug

The parts in the pump NOT changed:

Push me-Pull me valves and springs
Pump Body
Regulator Spring
Regulator O-Ring

From the basement of YS Hell . . . . . . . . . electric is starting to look better . . . . . .

_____________________________

Mrs. Kane`s Husband

(in reply to getterflash)

RE: 140DZ - 6/18/2007 8:50:16 AM

XMANS

Posts: 91
Joined: 8/8/2004
From: HOPPERS CROSSING VICTORIA, AUSTRALIA
Status: offline

Sorry to butt in again but it seems to be temperature related and you say don't sound quite right at half throuttle, which reminds me of a new engine I serviced a few months ago.

The problem was tracked down to a air leak between the chambers in the carby base, which only became evident as the engine temp rose.

Refacing the carby base, insulator block and backplate cured the problem.

Maybe its worth a try.

Team Crossman

(in reply to getterflash)

RE: 140DZ - 6/18/2007 5:33:39 PM

Posts: 60
Joined: 1/26/2003
From: Wyandotte, MI, USA
Status: offline

Thanks I'll take a look at it. I have not removed the throttle body or back plate yet, been focused on the pump.

_____________________________

Mrs. Kane`s Husband

(in reply to XMANS)

RE: 140DZ - 6/19/2007 4:16:06 AM

Posts: 60
Joined: 1/26/2003
From: Wyandotte, MI, USA
Status: offline