I recently had my YS 91 returned after the gasport mod by YS Service. After running PM 30 Heli fuel and an APC 15-6 prop the engine drips large amounts of fuel, for a long time, out the muffler. Is this normal?

Some leakage is normal, but just a drip is more normal. Turn the regulator 1/4 turn clockwise and it should improve. Always relieve the tank pressure after shutting off the engine.

Dave Shadel
Recently purchased a YS 91 AC to get my feet wet on YS engines. Engine arrived with a bent needle valve, so I ordered a new one from Central Hobbies. I noticed that the changed from buying individual components to a needle assembly that said YS 140 on package ( 1 YSE2740 ). It looks slightly different that the stock one. Am I safe to use it or should I question Central Hobbies? Any help would be appreciated.

Doug W.

No problem, it is the later version. It should work just fine.

Thanks Dave Also by the way. Who or where is YS support?

Doug

I don't understand your question. Do you mean the service dept?

Sorry for the confusion. Yes is the service department an authorized division of YS and something established here by say Horizon Hobbies or separate from all the above? I see all these references to YS service and wanted some background if I need to deal with them.

Doug

YS Service is not a division of YS in Japan, but is the factory authorized repair facility for the Western Hemisphere.

YS Performance is the importer for YS engines here in the USA. They have no connection with any other company.

Dave Simple question. Hobbico ARO, is it safe, or necessary for YS engines? I have always used it on my other engines when they will not be used for a week or so.

Doug

ABSOLUTELY NOT! 99% of commercial after run products will destroy the silicone parts in YS engines. For a compatible oil, go to www.pspec.com It's known as Ultra Oil, and is fully compatible with all model engine brands.

Dave
I have a YS 63 that has been sitting and I though it would be a good idea to send it in to YS service for a check-up prior to installing. Can you tell me what is involved, I.E. complete tear down, new gaskets, reg. diaphram? And the average cost to return to running condition? Engine was running prior to storage one year ago.

Doug

It is impossible to give an estimate on repairs without seeing the engine. Service charges $30 per hour plus parts and return shipping.

Your best approach is to send the engine with a request for an estimate, and give them a daytime phone number. That way there are no surprises.

YS Service
1295 Industrial Court
Gardnerville, NV 89410

Thanks Dave
That makes the most sense. Also maybe you can shed some light on valve cover gaskets that Central Hobbies sells. They now only offer them in a complete set that cost $12.95.(91AC) Awful expensive price to pay when valve clearance should be checked regularly and new gasket installed each time.

Doug

Use the stock gaskets, they work just fine.

Dave (Stock gasket)? Do you mean reuse the one that's on?

Doug

If it's not damaged, why not? What I meant was use stock gaskets and don't waste money on the aftermarket replacements.

Dave
The following is my observations of a problem that someone else and myself were having concerning deadstick problems with YS. Engine was adjusted on the ground and top end was richened down 3 or 4 hundred rpms and low end would idle at 2100 forever. Prop was
APC 15 x 4W, fuel Wildcat 30%(Jack Youngblood 23% oil)

"I had the same problem with my 91AC. It ran great on the ground and quit in the air. One thing you didn't mention was whether the engine was hot or not. When my engine quit, both times it was too warm to keep your hand on even though it was uncowled. I was flying at 1/2 throttle or less both flights. I richened the reg. and am now waiting on a decent day to try it out. If the low speed needle controls 1800-2400 rpms, and high speed control top end, then is it possible that the mid-range is controlled by the regulator, and running too lean will cause the over-heating and dead-sticks? Just askin?"

This is from the YS Club forum. Any ideas would be appreciated.
Doug

I think maybe I've said about a hundred times that the reg controls mid range. If you are constantly running in the mid range, maybe a little richer would help, but it may foul up the transition somewhat. The only thing to do is try it.

My hunch, though, is that you are hovering the airplane in the mid range constantly and not getting enough cooling airflow around the engine. Don't forget that hovering loads the engine very heavily and they will tend to run hotter than they would at full throttle in level flight.

Good Luck!

Dave
Sorry for asking redundant questions. I should have checked the other forums first.
Actually the mid-range flying is being done on a Waco bipe that weights 7 1/2 lbs. and
flys around beautifully at 1/3 throttle on the 91. (no hovering here). Which I guess really surprized me when the engine quit. Where should the temp be on a engine flying w/o much load and flying a 51 X 4w prop. Is it possible that the pitch prop I'm using is not moving enough air over engine?

Doug

The prop you are using isn't much prop, but at partial throttle, it should not be causing a problem. Try dropping back to 20% nitro fuel. If the problem goes away, the culprit is excess heat from the fuel. We use Cool Power 30% heli here and have great success with it.

Good Luck!

Thanks Dave
You may have something there with the fuel. I had bought a gallon of 30% Wildcat (23%oil) to try in my YSs because all my other fuel had castor in it for my Saitos and I didn't want to take a chance with that fuel in my YS. Dang!

Doug

I can tell you from a lot of experience that YS engines are the most fuel critical engines on the planet. If you have trouble right after switching fuel brands or even a new gallon of the same brand, check the engine again with a "known" good fuel.

Dave does anyone make muffler adapters to bring the muffler straight out from engine instead of pointed rearward? This is for the YS63.

Doug

I know Dave Shadel makes some mufflers for the 4 stroke engines.

try

Performance Specialties

http://www.pspec.com/results.asp?category=4

Troy Newman
Team YS performance

Thanks Troy
Have you taken over for Dave in the forums? Really great being able to get sould advice on RC problems and especially on YS engines.

Doug