YS 170DZ problem
#1
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From: indian trail,
NC
After 170 flights with absolutely no problems, I developed a problem of the engine quiting in flight, not abruptly just winding down to a stop. Feeling it was too rich, I had 2 turns out, I started at 1 and 1/2 and had good success through about 5 flights, now did it again and I've changed plug, move the needle out and back in, and the engine will start but can't keep the low in running and when I move it to high throttle it acts like it want to quit again. I thought about moving the pump screw but ain't got a clue which way or if that will help. Is it outside or inside the engine?
#3

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From: Randolph,
NJ
ORIGINAL: rcpattern
On new engines the backplate screws tend to loosen up and will give you the exact problem you are having. Pull the engine and retighten all the screws. Once you tighten them again they will stay tight, but I would bet you have an air leak somewhere,
Arch
On new engines the backplate screws tend to loosen up and will give you the exact problem you are having. Pull the engine and retighten all the screws. Once you tighten them again they will stay tight, but I would bet you have an air leak somewhere,
Arch
#4
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From: indian trail,
NC
ORIGINAL: n1369e
After 170 flights with absolutely no problems, I developed a problem of the engine quiting in flight, not abruptly just winding down to a stop. Feeling it was too rich, I had 2 turns out, I started at 1 and 1/2 and had good success through about 5 flights, now did it again and I've changed plug, move the needle out and back in, and the engine will start but can't keep the low in running and when I move it to high throttle it acts like it want to quit again. I thought about moving the pump screw but ain't got a clue which way or if that will help. Is it outside or inside the engine?
After 170 flights with absolutely no problems, I developed a problem of the engine quiting in flight, not abruptly just winding down to a stop. Feeling it was too rich, I had 2 turns out, I started at 1 and 1/2 and had good success through about 5 flights, now did it again and I've changed plug, move the needle out and back in, and the engine will start but can't keep the low in running and when I move it to high throttle it acts like it want to quit again. I thought about moving the pump screw but ain't got a clue which way or if that will help. Is it outside or inside the engine?
#5
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From: indian trail,
NC
Thanks gentlemen for your quick responses. I have sent the motor to us service
and was told the crank shaft is bent by .8000. A new crank was installed January of 09.
Motor has not been in a crash. All results not known yet. Will post when known.
and was told the crank shaft is bent by .8000. A new crank was installed January of 09.
Motor has not been in a crash. All results not known yet. Will post when known.
#7
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From: indian trail,
NC
Received the engine back from service in Arizona. Richard told me the crank was bent, the bearings were shot, the piston ring needed replacing. He did me right and charged no labor, and only for some of the parts. I figured about 25% for what could have been. He certainly helped me out.
#11

Here's normal wear and tear... Rear bearing in a brand new DZ170cdi with about 50 flights on it (15% nitro, 20% oil).
You can see the bits floating in the puddle of oil.....
You can see the bits floating in the puddle of oil.....
#12

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I don't want to say too much but, you might be better off stopping your tear down at this point, packaging it up and sending this particular YS motor to Richard at Performance Specialties. It appears the ball bearing shield of the rear bearing in the above photo has disintegrated. I ran these motors for years and had similiar problems. Back then, I tried everything that was suggested. Based on your opening statement in this thread and the problems you and others have had, this is probably not a fluke! Thanks__Everette
#13

You sound bored there TN Walker,
I don`t remember you running a YS since the 120 days,
In fact I haven't even see you flying at a contest in five or six years. back then I recall you using 2 strokes
have you even seen a 170
Bryan
I don`t remember you running a YS since the 120 days,
In fact I haven't even see you flying at a contest in five or six years. back then I recall you using 2 strokes
have you even seen a 170

Bryan
#14
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From: huntsville,
AL
I would say that is not normal for 50 flights on the 170 dz. I've been running them Dz's for the past 5 years and haven't seen that after only 50 flights. Warranty should be able to take care of this. But thats not my call. I generally get 12 to 15 cases fuel before i replace the bearings and ring to avoid such a failure .
gary
gary
#15

I've just fired off an e-mail to whom I bought the engine with some pics and I'll see what will happen.
I probably should have just pulled the engine and sent it back but I live in Australia and I bought it overseas. Now I've stripped the motor I don't really expect any support, a new rear bearing posted free of charge would be the best I could hope for as I certainly won't be posting them a box full of motor bits. Given how well the engine is sealed up I'm surprised how the oil manages to work itself around to all the bits...
I probably should have just pulled the engine and sent it back but I live in Australia and I bought it overseas. Now I've stripped the motor I don't really expect any support, a new rear bearing posted free of charge would be the best I could hope for as I certainly won't be posting them a box full of motor bits. Given how well the engine is sealed up I'm surprised how the oil manages to work itself around to all the bits...
#16
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From: huntsville,
AL
if warranty is not granted. Clean the motor with dish soap and a tooth brush being sure to dry it before oxidation sets in on the metal and install the new bearings using a zip wire tie to squeeze the crank ring while pushing the crank in the final bearing seat. it takes a bit of patience but its not that difficult.
gary
gary
#17

Thanks Gary, I just pulled the bearing apart last night and I found the inner race damaged in a local area. I have only ever had one bearing with this type of race damage and it was a stainless/ceramic hybrid front bearing used in my Hanno but as I hand start that I caught it early before it fell apart. I replaced it with a new OS part and it's still going strong..
#18
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From: huntsville,
AL
I'm no rocket scientist but that looks like a metallurgy issue. Not necessarily a ys quality problem more of a bearing supplier issue. But I hope they will warranty it either way.
gary
gary
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From: Perth, AUSTRALIA
Yeah, I'd say the same, looks like porosity, it may have been just under the ground surface, or juuust poking through, but after a few thousand balls have run over it, it may have chosen to part company.
#20

Good News!!,
word from YS is they'll fix it under warranty so it looks like I will be shipping a box of bits to Japan.
Interesting, they suggested I try the new APC 20x10.5 prop when I get it back.
Google doesn't seem to know much about this prop???
word from YS is they'll fix it under warranty so it looks like I will be shipping a box of bits to Japan.
Interesting, they suggested I try the new APC 20x10.5 prop when I get it back.
Google doesn't seem to know much about this prop???
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From: oakland,
CA
ORIGINAL: bjr_93tz
Good News!!,
word from YS is they'll fix it under warranty so it looks like I will be shipping a box of bits to Japan.
Interesting, they suggested I try the new APC 20x10.5 prop when I get it back.
Google doesn't seem to know much about this prop???
Good News!!,
word from YS is they'll fix it under warranty so it looks like I will be shipping a box of bits to Japan.
Interesting, they suggested I try the new APC 20x10.5 prop when I get it back.
Google doesn't seem to know much about this prop???
I have just started using this prop about a month ago on my cdi with CP 20% fuel, it's turning about 7,000 on the ground, but you'll have more than enough power for the verticals. Down line is nice & slow.
You can order from Central Hobbies or direct from APC.
Adrian



