Freddy

My Feedback: (3)

I am recently breaking in a new YS170DZ engine and ran several tanks of Cool Power YS 20/20 fuel through it on the ground and use the APC 18.1x10W prop. On the ground the idle, mid range, and top end are perfect but as soon as I get airborne on the downwind leg the engine just quits while at a mid to mid/high throttle setting. The needle is open 2 turns. I was afraid to close it more as the engine is still new. Or should I just close it to 1.5 -1.75 turns?

I put the engine in a used Angel's Shadow which came with a long pipe see picture. Could it be that they only run well on the Hatori short pipe? Have you guys had experience with using the long pipe for the YS170DZ?

Thanks in advance for any ideas.

Don Szczur

My Feedback: (1)

Do this, that, that and this and then solved..

Regards,
Don

P.,S., likely fuel issue. I have my needle at 2 1/4 to 2 1/2 turns out on my 170. Overheating check ventalation for exit air. Check valves working ok. Tank is getting vent and no suctioning, Do you run a fuel filter between the tank and the needle valve. Pull the needle valve out and push fuel though it just in case. When it quits does it knock hard or just quit smoothly. Take a video and post to youtube. Best, Don

apereira

Freddy,

Close the needle to 1 1/2 max or go directly to 1 1/4 turns.

Regards

Alejandro

kenh3497

We have one person that says 2 1/2 turn out on the HS and another that says 1 1/4 turns out. That is a VERY wide range for the same engine. There must be something amiss with one or both of those engines

I agree with Don's post "When it quits does it knock hard or just quit smoothly". This info will help diagnose the issue. In addition have you used a tach to adjust the high speed mixture? Peak the RPM with the tach and then just slightly rich. I'm fairly new to YS so I'll stick my foot in my mouth and say 300 RPM rich.

Ken

apereira

Freddy,

I did not see the picture last night, is that a two stroke pipe or four stroke muffler?

Regards

Alejandro

bjr_93tz

I'm betting it's a non-cdi 170 so the richer of the two needle settings might (?) be the right one. If it's the cdi version, the leaner recomendation of the two would be closer but I've only ever used the low oil, cdi version. The needle settings decribed are only ballparks, a tacho is your best friend then fine tune in the air. I'd tend to agree and think it's a fraction rich top or bottom or both.

I had a cdi issue a few years back which drove me mad doing exactly what's described. You could tune it all day on the ground and it would quit on the downwind leg after takeoff, it turned out the sensor in the crankcase was intermittantly faulty in a strangely consistant type of way??

drac1

My Feedback: (4)

Ys's will usually run very rich without quitting, so I don't think that is the problem. Could be a lean regulator.

drac1

My Feedback: (4)

Doesn't look like a four stroke muffler. The 160 runs fine on a long muffler, but haven't tried 170 and above.

apereira

It's because I have a Long Hattori which looks like a two stroke pipe.

Regards

Alejandro Pereira

Freddy

My Feedback: (3)

I will use my tachometer next time before setting the needle to go airborne. I am not sure what type of muffler this long one is 2 or 4 stroke. I believe they used it with a YS140FZ. It is pretty small in diameter. If I recall it just lost rpm rapidly and quit.