I am going to re-direct this question since the YSSupport forum seems to be inactive.

I have been sitting on a 170 for a while now and finally putting into an airframe. What is the purpose of the foam fuel tank pick up supplied? (other than additional filtering?)

Will the Tetra bubbless tank work with this engine being it's vented instead of pressurized? I am currently setting up a standard Dubro tank since I am unsure.

This is not the CDIVersion although I am running the Sullivan programable glow driver (M060http://sullivanproducts.com/ModelProductsMainFrame.htm )since it's mounted inverted. Powered by a 6.2V - 2100mah LiFe pack.

Fuel is YS20/20 for break-in. I have cool Power 30%Heli available as well.

The above question and any additional tips appreciated. This is not my fist YS(They are all I use).... although my first run at the 'vented' instead of pressurized YS.

I am also looking at the Hyde Adjustable rail mount for use (non-nose ring) - Type AJ... since this going in a sport plane. Any info on this mount without using a nose ring is appreciated as well.

The foam clunk is there to try and prevent bubbles from entering the fuel lines. The pump has a small piston and small stroke so any air in the system in the pump or downstream from it can upset it's ability to generate full desired pressure and/or draw more fuel from the tank. Just think of air trapped in your car brake system, the fuel system gets a bit spongey untill the bubbles pass through.

A bubbleless tank will perform the job provided you get all the air out.

The pump will self clear bubbles 99.99% of the time, it has to as I break my fuel lines between the pump and tank to fill it which can leave an inch of air in the line, but I wouldn't want to be a full throttle when that inch long bubble hits the pump, just in case of a lean misfire.

I have no experience with the non-cdi version, but rumour has it they need to be run fairly rich?

Cheers

THanks for the reply.   The foam 'wetted area' is something I can see helping.   The Tetra tank has a bladder and a fill vent to extract air while filling.  It is pluged in flight.  There is a seperate pressure line that puts the pressure between the tank and bladder.  May pull one from the parts drawer and see how it will work with this on the stand. 

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I had a new ys 170 and I had trouble breaking it in. I gave it to Mickey L. and he broke it in for me. He said you need to use fuel with castor oil in it for break in.

Interesting.... I use Omega (castor/syn blend) my other engines and in the older YS120 _ (it's about 18 yrs old... the first 120 offered by YS and still running strong.). but the literature says it's ok to do so... but limited to 2% castor on the 170. I am using VP 20/20 for breakin then planning to use 30% pattern or Cool Power 30% Heli for flights.

Never use castor on a Ys , never, don't use the bubleless tank, just use the foam clunk, the foam clunck is the modern equivalent of the bubbleless tank, it works perfectly, use the CDI included with the engine, Sullivan? Why? Thenoriginal setup is perfect! And it is trouble free. Don't reinvent the whell with all due respect.

I have 2 YS170 CDI. For breaking I run a couple of 16oz tanks with 30% Cool Power fuel. For the breaking I used glow, instead of the CDI. I do it because on glow you open the needle to a richer mixture, and that way preventing any over heating. Also, for breaking I use a 18.1 x 10 APC prop. I use the same prop for the first 4-5 fligths, swithching to 19 x 11 later.
I use the foam cover clunker. When done with flying, I run the engine dry, and left the remaining fuel in the tank.
Last engine that I sent to YS Parts and Service, was installed the last day of 2012 Nats, and run without problems until about 3 weeks ago when started having some issues idling. It had a total of 278 flights.
Time that I reset pump/needle: 0

Very, very nice power plant if you do not screw around with it.

Good luck

Rene

I am guessing from what you have posted that it is the glow version not the cdi. If it is the cdi then use the ignition system that came with the engine. If it is the glow version, there is definitely no need to run an on board glow driver. If the engine is tuned properly it will idle forever (inverted), and not die when throttling up.
All YS's from the 140DZ onwards are pumped, therefore no need to pressurize anything.
I have been using the Tettra bubbless tank for over ten years on the 140DZ, 160DZ, 170DZ cdi and the 175DZ cdi engines and never had a engine stop due to air in the fuel system. This is the most reliable fuel tank i have ever used. Set up the fuel tank exactly as the instructions show.
The nipple on the tank that vents to atmosphere is not a pressure fitting. As the engine is pumped, the pump will draw the fuel out of the tank without any pressure required. This vent must not be plugged. It allows the bladder to collapse as the fuel is drawn out. If it is plugged it will create a vaccuum as the pump tries to draw the fuel out starving the engine of fuel. It is a good idea to run fuel tube from this nipple to outside the fuselage (through the floor), so if there is an internal leak anytime the fuel will not be soaking the inside of your model.
Most YS users have there own preferred fuel mix and i am no different. In glow engines i use 30% nitro, 19% Coolpower purple oil and 1% castor. In cdi engines i use 30% nitro, 8% Coolpower purple oil and 1% castor. I've never had any problems using these fuel mixes.

Once the needle and reg are set. RESIST THE URGE TO FIDDLE.

Removed double post.

Good Info guys and I appreciate it.   YES, this is the glow version.   The tetra tanks are my favorite on the pressurized version and I see no reason why it wouldnt work.  I should have the engine ready on the stand tonight to start break in.   Will be using a 18x10 prop on the stand to keep the load down and VP/Powermaster YS20/20 for the first gallon.  Subsequently I will go to the 'standard' Cool Power 30% Heli. ( I do not mix my own fuel).  
RE:Fuel...   I was talking to the tech guy at VP yeserday and he was saying they are selling alot of 40% Pattern blend.   40%Nitro /20% Synthetic.  That is interesting although seems like a lot.  

AGREE on set it and dont fiddle with it.  I have an old 1.20 that is about 20 years old that still runs great.  I did put a new diaphram in it once a few years ago.