Breaking in the YS

First a few tips to get started:

Use the APC 18.1-10 or 19-11, Cool Power 30%LS Low Smoke or regular Heli fuel to break in and for normal flying longevity. Don`t use the 10% oil fuel it`s too brutal on the Pump and will prematurely wear it out along with cooling problems. I recommend Cool Power 30% nitro Heli or low smoke fuel.

If you are using the glow version get a Glow driver with a start delay . The 1.7 can be brutal on the first starts without a delay. Do not attempt to ever start it without a delay on your glow driver. You can break the front of the cowling when it backfires. Call Central Hobbies for the Rcats glow driver, they also sell a Couple of other brands, I recommend the RCAT.

I would suggest to run the motor on a test stand if possible for a few tanks before installing it, to get used of it`s quirks. If that is not possible, because of the tight fit at break- in the engine can run hot so I would leave the cowling off for the first run or two, or until you get a good cool run and the correct needle settings.

I would get to know the 1.7 some before installing it. It is a beast of a motor, but once it is set it is the most reliable, powerful, and consistent motor YS has ever produced.

Next a few quick warnings:

This motor can and will throw the prop if you carelessly operate it, you have to be very careful while operating it during break in.

If the pump is too rich it will buck and bark, in the low throttle transfer and mid range, and spin the spinner and prop on the thrust washer and ruin the thrust washer, so be sure you tighten the prop good!

This motor can get HOT and Vapor lock. If it happens during break in, or flying, let the engine cool and retry when it cools down.

If you are using a YS mount it can lead to loosening your mounting bolts. Also it will put undue stress on the CDI plug cap/wire connection and could possibly break the plug electrode.

So lets get started, shall we?

1.  Pull the cam cover , and add a 4-5 drops of synthetic Klots oil
2.  Remove the plug and spin the motor up good on the stand by hand  to make sure the motor gets well lubricated do not put fuel at this time.
3.  Set the main needle to 1.5 turns out and the pump about 1/2 turn in from flush to start. 4.  Next add a few drops of fuel in the carb, and spin it up by hand again.
5.  Install the plug.
6.  Next hook up the fuel line, hit your delay button on the glow driver, and start it.
7.  Keep it on a high Idle for a while. Slowly advance it to about 1/3-1/2 throttle no more on the first run.
8.  If it seems to not want to take fuel (slow -delay to respond to throttle input) when you advance the throttle, turn the pump regulator screw in 1/4 turn at a time (richening the pump) until it advances smooth.
9.  If it barks and stumbles. Turn the regulator screw out 1/4 at a time slowly check the throttle advance again to get a smooth transition.
10.  After you run the tank out of fuel, let the motor completely cool .
11.  Refuel and start it again only this time you can advance to high throttle. Try to keep it running as rich as possible with out barking or burbling.
12.  You should be able to get a consistent run after your second- third tank. And you will need to lean the motor pump and high needle a little after about a gallon of fuel when the motor loosens up some.

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