Notices
RC Pattern Flying Discuss all topics pertaining to RC Pattern Flying in this forum.

YS 170 DZ CDI

Old 03-06-2011, 01:26 AM
  #176  
NJRCFLYER2
My Feedback: (42)
 
Join Date: Jul 2004
Location: Randolph, NJ
Posts: 878
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

No, you should not use a pair of unregulated A123 cells to power the CDI unit. It is limited to 6V operation.
Old 03-06-2011, 01:33 AM
  #177  
UKpatternflyer
 
Join Date: Dec 2004
Location: Crewe, UNITED KINGDOM
Posts: 165
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Hi Chris,

No I as referring to Lipo's, but the over voltage will still apply to your LiFePO cells

Best

Keith

ORIGINAL: topiwala

Hi Keith,
Sorry, just to clarify. I was referring to LiFePO cells, which are also known as A123. A 2 cell pack's nominal is 6.6v. Is this what you were also referring to? Or have I misunderstood. I acknowledge the V limits on the CDI, to 6v.
My question is - Would a 2 cell A123 pack do without Vregs.

Chrs

Mayur

Old 03-17-2011, 04:55 AM
  #178  
bjr_93tz
 
Join Date: Dec 2006
Location: ToowoombaQLD, AUSTRALIA
Posts: 1,026
Likes: 0
Received 16 Likes on 14 Posts
Default RE: YS 170 DZ CDI

If I wanted to run my 170cdi (low oil) on a glow plug, would the OS F plug be suitable and should I use 20% oil or would 15% oil be ok for a tank or two?

Also I should be able to get away with a non-delay glow driver for just a few starts?

Cheers
Brett
Old 03-18-2011, 08:59 PM
  #179  
topiwala
 
Join Date: Sep 2010
Location: AucklandAuckland, NEW ZEALAND
Posts: 184
Likes: 0
Received 1 Like on 1 Post
Default RE: YS 170 DZ CDI

Well gents, 
re"> My new YS CDI has finally flown in a Comp-arf Valiant - 4 flights. Awesome!! Surprisingly, after 4 flights, the needle valve is only open a little under 3/4 open!! The regulator had to come out atleast a turn from flush. Even then the engine has an occasional rich cough. Running a 18.1x11 APC. 
The second flight dead sticked when the needle valve was still at a little under 1 turn. Had to close it a few clicks to get it humming again. But all was well after that. The engine behaviour was consistent for the remaining flights. The engine is running cool as well. Head temps straight after landing were in the 'touchable' range!!!! Running 10% cool power red and 20% nitro mix. All seems to be well. I can't wait until the next session!

Will post back after the next session to highlight any changes in the engine behaviour. I'm 'almost' 100% confident with it.

Rgds

Mayur
Old 03-19-2011, 07:53 AM
  #180  
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,738
Received 5 Likes on 4 Posts
Default RE: YS 170 DZ CDI

Hello Brett,

You can run the CDI on an F glow plug, it's the same as the YS4 and it is the correct plug. You can run 15% or lower oil content with no problems, but the engine will last longer on 20%, so 15 for a few flights or even competition should be fine.

You should not use a glow driver with no delay, if the engine backfires you could bend a valve, if you don't have adelayed glow driver, try to pu a switch if it has cable or have some to conct it after the prop is spinning.

Best regards

Alejandro P.
Old 03-19-2011, 01:40 PM
  #181  
bjr_93tz
 
Join Date: Dec 2006
Location: ToowoombaQLD, AUSTRALIA
Posts: 1,026
Likes: 0
Received 16 Likes on 14 Posts
Default RE: YS 170 DZ CDI

Thanks Alejandro,

I'll pop it back up to 20% and work out some glow driver arrangement. I can fit a normal Ni-cd through the cdi switch (cdi removed of course) and wire it down to the glow plug and have a helper switch it on once the engine is turning (or make up and electronic delay?).
I am waiting on a new sensor/disk valve assembly to arrive and will try that first.

I don't have the holes in my cowling to access a glow plug so I have reluctant to try that, it is a last resort option. I might make up a "drop-in" system as a backup, so in the future I can pull the cdi and swap over to glow in a matter of minutes should I have problems at a comp.

I just wish whatever is causing the problem would just stop working so I can find it rather than being an intermittant problem...[:@]

Old 03-20-2011, 05:43 AM
  #182  
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,738
Received 5 Likes on 4 Posts
Default RE: YS 170 DZ CDI

Hello Brett,

Sorry, I did not how many errors I made when typiying on the previous post.

We had in our team an engine with a bad hall sensor, and that, can be an intermittent problem for sure, hope that's what it is, the only thing to remember is, the regulator adjustment might change either a little or a lot, engines tend to be quite different here between CDI or the glow plug.

May I suggest, put a wire on any of the engine mount bolts and use it as ground and just make a conection for the positive on the plug? so you don't have to open a hole on the fuse, what about this, use an old servo extension, use two wires and leave the other side of the conector out somewere so you only use the opposite end of the extension from the glow driver, the conection itself will be the switch, but needs to people.

Hope this helps.

Regards

Alejandro P.
Old 03-20-2011, 09:49 AM
  #183  
topiwala
 
Join Date: Sep 2010
Location: AucklandAuckland, NEW ZEALAND
Posts: 184
Likes: 0
Received 1 Like on 1 Post
Default RE: YS 170 DZ CDI

Hi All,
re"> I'd like to know from you on how your needle and regulator settings are with the CDI. My one is around 3/4 open on the main needle. The regulator is also about 3/4 turn open from flush. The main needle setting of 3/4 sounded really shocking to me, when the engine is still , ever so slightly, on the rich side. 

Looking forward to replies

Mayur

Old 03-20-2011, 10:12 AM
  #184  
Torben Parsberg
Senior Member
 
Join Date: Nov 2006
Location: hedensted, DENMARK
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

hi
yes , its shocking 3/4 on main needle,
the regulator is ok..
i have 3 170 cdi , low... all have 1,1/4 on main needle + - 1-2 clik,,
and the reg,, is ½ to 1 turn from flush
and the litel needle 1/8 turn open on all
fuel 12,5 oil 20% nitro home blend.
rpm on apc 20 10,5 7400-7500
pump temp,, 68*
Old 03-20-2011, 10:14 AM
  #185  
Torben Parsberg
Senior Member
 
Join Date: Nov 2006
Location: hedensted, DENMARK
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Oh forget
MAx temp in flight..
Old 03-20-2011, 11:07 PM
  #186  
topiwala
 
Join Date: Sep 2010
Location: AucklandAuckland, NEW ZEALAND
Posts: 184
Likes: 0
Received 1 Like on 1 Post
Default RE: YS 170 DZ CDI

For the needle settings. My initial concern was perhaps a false indication of rich running due to spark plug. But with around 1 turn open, the engine smokes like anything. And it is a genuine rich run. I am running 10% oil with 20% nitro. So with only 10% oil, it may be about right with 3/4 needle. I would like to know from anyone else on this as well. What is the general consensus? I'm happy to continue running at 3/4 needle if the engine is happy.
Old 04-24-2011, 04:21 AM
  #187  
sleeping
Member
 
Join Date: Feb 2008
Location: Perth, Australia
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Please explain!

What is the purpose of the fuel line that runs up parallel from the carby to the inlet manifold and that it's a one way check valve that runs into the combustion chamber?

Btzj ?!

Crossman, hi! Need to call you
Old 04-24-2011, 04:41 AM
  #188  
bjr_93tz
 
Join Date: Dec 2006
Location: ToowoombaQLD, AUSTRALIA
Posts: 1,026
Likes: 0
Received 16 Likes on 14 Posts
Default RE: YS 170 DZ CDI

Hi Sleeping,

the line running from the pump to the throttle body (it's not really a carburetter), is a high pressure supply to the fuel metering arrangement in the throttle body.

The line running from the throttle body up along the intake tube to the black check valve on the head carries that metered fuel up to the check valve where it's injected into the motor. No fuel (apart from a small amount bypassed by the sub needle valve) goes into the motor crankcase via the throttle body. It all gets squirted in at the intake valve as the valve opens, as below the black check valve there's a small needle that is pointed at the intake valve.

When I prime the motor for the first start of the day, I fill the tank, draw fuel to the pump then connect the line to the pump. Open the throttle flat out and rock the engine back and forth and you'll see the fuel discharge from the pump in pulses, travel to the throttle body, then up to the check valve. Once it's at the check valve, a couple more rocks, close the throttle, power up the ignition and it good to go....

Old 04-24-2011, 01:48 PM
  #189  
sleeping
Member
 
Join Date: Feb 2008
Location: Perth, Australia
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Thanks for the explanation.

Of course I believe you as you have run and rebuilt! your motor, mine is still in the box... But it just doesn't sit well for some reason? I'll explain what I think is happening;

I'm cool with how the reg and the pump works ( I hope...) it's easy if I refer to the manual for part numbers just so we avoid mixing words yeah?

The pump is driven by the intake pushrod that runs of the cam, this rod is split into parts 61 & 62 which run the tappet for the intake valve as where the exhaust pushrod is not split. As has been noted the pump and reg are combined. The diaphragm within the pump 48 is deformed by the 'button head plungers' 52 & 53 that move in and out perpendicular to the pushrod. One very clever design move is the fuel line down from the Regulator Body 45 to the crankcase. Remembering that there is no pressure in the crankcase, by inserting this line it ensures that the diaphragm will never have any - air - pressure on it's side facing to the front of the engine. That pressure is determined by the Reg spring only and that is why we are told to adjust the idle mixture via the reg screw ( onto the spring ) my old 160 was very different and the reg was 'not to be touched ' as it was factory set. A completely different system. The same goes for the reg on my us Heli engines. A different system again.

Back on track...

Once the fuel exits the pump via the line that connects to the nipple on top of the carb body 63.

In your post you noted that this line was a high pressure fuel line. I think it would be better to cite that as fuel under standard pressure; After all, that is the whole job of the reg. High pressure fuel coming into the throttle body would give the high speed needle no chance to fine tune the flow of fuel. To that point, if the reg was wound out too far it would render the high speed needle useless.

To cover off the sub-needle valve, straight off the instructions, that simple let's a little bit of fuel into the crankcase to lubricate the bearings and keep things cool.

There are some very complex timing ports 28, 30,31 that double up as the backplate onto the carb body that I have no idea about without pulling apart the engine. I am assuming they are opened and shut by the back of the crankshaft.

From here, things just aren't adding up...

Let's stick with full throttle to keep things simple; it's time for the fuel and air to mix. The correct fuel flow rate has been established by the pump/reg/ high speed needle and the carby is fully open.

In my head, the mix is completed in the carb body and the travels up the intake pipe 79 when the intake valve 7 is opened. The intake valve then closes and that phase of the cycle is complete.

In your post you noted" It all gets squirted in at the intake valve as the valve opens, as below the black check valve there's a small needle that is pointed at the intake valve. "

I cannot see any needle near the top of the cylinder head; physically or in the exploded diagram. The role of the sub-needle we've covered off.

In my mind, it's the intake pipe that delivers the air & fuel mix to the combustion chamber.

It makes no sense to inject the fuel into the chamber at the top of the head via a one-way check / bleed valve.
Unless I am reading your explanation wrong ( Ohms law!!)?


I think the role of the fuel line in question is to allow any fuel below the cylinder head a path of escape. This ensures there is never a residual build up, or pool, of fuel hanging around the carb body which would upset things. Remembering that via the sub-needle we are directing a small amount of fuel into the crankcase. It needs an easy path of escape. That in my mind makes sense. OS use the same method on the OS 200 standard (not f3A). And although that line may always full of fuel the flow rate would be much lower than the flow rate of the fuel coming from the pump. The one thing the instructions don't cover is adjusting the 'bleed' of that valve which has a direct -force - pressure differential on the fuel that us trying to exit the crankcase. The instructions give fair warning about opening the sub needle too far. But if you're engine is running too hot, but if you open the sub-needle it will affect the motor's performance, in theory (if I have got it right) you could open the bleed valve a little and the sub needle a little which, in effect, would see a greater flow of fuel below the cylinder head - in & out - to cool the engine without affecting the overall performance. The answer is in those timing ports....

I-will-fixit, what is the answer????

Cheers to all. Wrong or right I will ultimately know exactly how every bit of this engine works. So come set-up time, it will be easier to diagnose any issues

Thanks to all
I'm asleep
Old 04-24-2011, 02:42 PM
  #190  
bjr_93tz
 
Join Date: Dec 2006
Location: ToowoombaQLD, AUSTRALIA
Posts: 1,026
Likes: 0
Received 16 Likes on 14 Posts
Default RE: YS 170 DZ CDI

Hi Sleeping,

The discharge form the pump is/can be high pressure. The clear tube running from the just in front of the cam gear housing up the the regulator allows the diaphram to "see" crankcase pressure which varies largely on throttle position and rpm. Don't forget, the engine uses a lot of it's internal volume as a plenum chamber for the supercharging process. I'd bet Will Crossman has some really intersting numbers in this area. I beleive he stated somewhere that fuel pressure can be up to 7psi, (or it may have been the pressure regulator sensing line). This would allow the fuel to maintain the correct pressure differential from pump discharge to the end of the injection needle.

Modern (I still drive a car with a carby, so any car with fuel injection is modern) fuel injected cars do the same thing, they have a fuel pressure regulator that senses the manifold pressure and adjusts the fuel pressure to maintain a constant pressure differential across the injector.

If you remove the intake tube from the head you'll see the shiny needle/tube pointing at the intake valve. All fuel goes in here, there's no fuel/air mix traveling up the intake pipe.

I haven't a clue what system the OS uses, the YS is my first 4-stroke and to be honest I know too much about it, much more than I ever wanted to know. I just wanted to pull it out of the box, put it in a plane, run it in and use it. I never wanted to have to strip it completely twice after bearing failures and fuelpump/ignition problems. Chasing down some obscure, intermittent fault over 5 months, isn't my idea of flying model airplanes at all....I also know too much about my car

As for diagnosing issues?? This is why it took me 5 months to sort mine out because I was wasting my time trying to figure out why my engine wasn't running right instead of just coughing up the cash and replacing parts until it worked again. If I had just dived into a magic toolbox and pulled out a new fuel pump, sparkplug, cdi unit and sensor, I'd have been back in the air trouble free in about 45 minutes...
Old 04-24-2011, 02:49 PM
  #191  
sleeping
Member
 
Join Date: Feb 2008
Location: Perth, Australia
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Well, again, that makes good sense!!

At least we take the time to learn...

Cheers
Old 10-17-2011, 09:55 AM
  #192  
Berk
Senior Member
 
Berk's Avatar
 
Join Date: Jul 2004
Location: Kings Lynn, UNITED KINGDOM
Posts: 236
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Sorry to ressurect an old thread, but I'm having issues with my 170Cdi not starting and flooding VERY easily.

I'm wondering whether it's the plug, but also I've discovered I have 2 diaphragms fitted to the pump and i'm not sure this should be the case! (the black one and the orange one). I'm guessing I have a newer pump as the poppet valves meet with the brass inserts in the pump body.

On the very rare occasions I can get it to run it runs great, albeit a little rich at bottom end as it slowly loads up at idle. Once flooded though that's it for the day. it will just fire in a nasty way every 10 turns of the prop. Ocasionally it shoots a flame out the exhaust with a loud pop!

Reg is 1 turn out from flush and needle is 3/4 turn out. Fuel is 20 oil 20 nitro.

Next step is to buy a new plug.

Regards,

Steve


Old 10-17-2011, 11:30 AM
  #193  
top1
Junior Member
 
Join Date: Dec 2003
Location: Auckland, NEW ZEALAND
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Hi
Take a look at your cdi unit. It seems like the cdi isn't firing consistently. This will cause flooding. Is your plug cap and lead secured somehow? I had to secure the lead to the air intake tube with a zip tie to make sure it didn't move around and cause intermittent connection issues. If not that then plug
Old 10-17-2011, 11:37 AM
  #194  
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,738
Received 5 Likes on 4 Posts
Default RE: YS 170 DZ CDI

For sure try a new plug, and on the pump, there is only one diaphragm either the black or the orange. The orange did not do so well so they did not used it anymore, stay with the black one or the one in best shape.

I do not remember where did I posted it, but look for a post that says to all YS users, and consider buying those two little and cheap tools, it will help you find ignition related problems easily.


Regards

Alejandro Pereira
Old 10-17-2011, 09:39 PM
  #195  
bjr_93tz
 
Join Date: Dec 2006
Location: ToowoombaQLD, AUSTRALIA
Posts: 1,026
Likes: 0
Received 16 Likes on 14 Posts
Default RE: YS 170 DZ CDI

My new "revised" pump has the two diaphrams and seems to work well.

With regard to oil content and the cdi, IMHO YS needed to go low oil for a reason and it had nothing to do with smoke trail.

Simply stated (in my case) the less oil the better. My DZ170cdi on 20% oil in my Aries will oil up the plug unless it's set super lean (top and bottom) or you spend the whole flight doing outside loops, even 15% oil is/was a bit marginal if I wanted to spend a couple of minutes just cruising around upright instead of flying the schedule. On the ground an oil fouled plug might clear itself if you're really lucky.

10% oil seems to be the ticket for me now with a prop that will let me turn about 7.5K+ rpm.

I'd bet my Aries that everyone has their own thing that works for their particular engine. I also learned two very important things (among many) from my experience starting out with a brand new YS engine, (1) NEVER buy a second hand one and (2) if it's been running great for ages and then you have to start touching the needle or reg, it's getting close to rebuild time and needle fiddling is only going to delay it.

Cheers

Old 10-18-2011, 07:29 AM
  #196  
arnstein
 
Join Date: Mar 2004
Location: Kongsberg, NORWAY
Posts: 67
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

I agree with bjr_93tz, 20% oil even low viscosity type seems to be too much for the engine to handle. I had the similar symptoms as Steve describes using 20% oil, reduced to 12% and later to 10% without any problems.Assuming you are running a“true” CDI with low oil parts.I think even lower oil content is possible, although I have seen reports that the pump wears more quickly.At 10% I have not noticed any reduced performance of the pump.

Arnstein
Old 10-18-2011, 07:40 AM
  #197  
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,738
Received 5 Likes on 4 Posts
Default RE: YS 170 DZ CDI

In my case, I run two 170 converted to CDI one low oil the other normal and the 170CDI version form Japan wich is low oil too, all run with 23% oil with no problems, at the WC we all got 23% oil fuel and nobody had problems with it.

Regards

Alejandro P.
Old 10-18-2011, 07:52 AM
  #198  
Berk
Senior Member
 
Berk's Avatar
 
Join Date: Jul 2004
Location: Kings Lynn, UNITED KINGDOM
Posts: 236
Likes: 0
Received 0 Likes on 0 Posts
Default RE: YS 170 DZ CDI

Guys,

Many thanks for your replies. I'm of the mind that 20% oil is within spec so it should be able to be made to run OK on it. Yes it is a true CDi and not a conversion. I have gallons of 20/20 fuel that need using up, and I like smoke trails!!

I'm dubious of the 2 Diaphragms and being 1 turn out from flush on the Reg and still being rich! Perhaps I'll try just one as has been suggested

Regards,

Steve


Old 10-18-2011, 01:32 PM
  #199  
bjr_93tz
 
Join Date: Dec 2006
Location: ToowoombaQLD, AUSTRALIA
Posts: 1,026
Likes: 0
Received 16 Likes on 14 Posts
Default RE: YS 170 DZ CDI

I probably should mention that I had to turn my new pump way out from flush as well, compared to the original pump which ran close to flush.

I'm still getting smoke on 10% oil but it's a touch rich as it's still breaking in from the latest rebuild.

Apereira, how often do you replace the plug? I wonder if trying to stretch out the plug life a bit makes it a bit sensitive with normal (20%) oil levels? I'm pretty cheap when it comes time to replacing the plug....

Cheers
Old 10-18-2011, 07:26 PM
  #200  
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,738
Received 5 Likes on 4 Posts
Default RE: YS 170 DZ CDI

I replace the plug every 80 flight just in case, but is not due to failure.

Regards

Alejandro P.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.