You mean drilling holes in the engine mount for the nose gear? They might be pre-drilled, based on some of the engine mount pictures you've posted.

Tom

Hey TriSquire - I enclosed some pictures, the NG stuff is already done, I am thinking of drilling thru what is there, get fuel feed thru even with carb. Gotta watch, the NG can rub the fuel line, make a hole.

Vince

I wasn't commenting on anything that you said, Taurus Flyer. At least not intentionally.

I like Cline/Iron Bay regulators and homemade systems that function like them. So, I'm on your side, believe it or not, Taurus Flyer.

I think the real problem is the remote needle valve feature, even if it isn't causing Crankpin's problems specifically. Heat transfer and additional air ingress points are part and parcel of this type of NVA. Notice that OS' latest two-stroke glow engine (IIRC), the OS.55AX, is equipped with a carb that has the needle valve back where it belongs.


Ed Cregger

Ed,

I was triggered because you wrote:

"We used to fly without them back then and never had any kind of a problem with fuel feed."

But you are right, we are on the same "wavelenght".

My opinion is that every glow engine has more or less the same problem, It depends on the exhaust pressure, tank position, carb ventury, etc. and that is solved by a regulator.
With a regulator you can get more power out of your engine because it is not necesairy to richen the adjustment of the air fuel ratio, so he also uses less fuel (Most important Dutch argument). It's a better solution than a remote adjustable needle valve,in the early days used by Webra, and maybe other Brands.
Overall pro, position of the plane has nearly no influence. When you realy have enough pressure you can place the tank in the center of gravity, but then you need a tap on the crankcase of the engine.

Warning for every 61 FX pilot, do not lean your adjustment to solve any problems!!!!!

A NVA on the front end of the engine is allways the best, but dangeraus for your fingers, the second point is the reason they build NVA on the back side I think.

Cees Wester

Vince,

I don't think that your problem is related to the rear placement of the needle valve assembly. After all, the venturi and the fuel inlet tube are still in the usual position up front. The fuel draw is determined by the venturi, not the placement of the needle valve assembly. After all, the NVA is just a metering device and it can be located anywhere in the path of the fuel line. As noted in an earlier post, the real issue is the location of the tank centerline relative to the spraybar in the venturi.
As to your specific problem, it is likely that there are several contributing factors with the most important one being the low end mixture - it is probably too rich. You might also try increasing your inflight idle setting. On my Cutlass I set the idle on the ground so that with full forward throttle trim I have a fast idle for airborne maneuvers. For landing I pull the trim back ten clicks (on a Futaba 9c xmtr). This gives a slow idle. I find that using a higher inflight idle setting helps with spin entries, acceleration after downlines, and stall turns. It yields more predictable throttle response during maneuvers.
As for fuel, I have been using Cool Power 20% ProPattern with no problems at all in my 61 FX. If you are having problems with Cool Power this may be indicative of operational settings or fuel system problems rather than problems with the fuel itself.


Jeff

Please guys, don't reach out and smack me for this post. I was reading all of the posts responding to Vince's initial fuel problem and all the ways that have been used/tried to solve or eliminate the problem. Last year and the year before I went through these problems with two airplanes. Each different in design, but with a fuel tank/engine placement incompatibility. After pumps, different motors, etc. they each got a YS 61 and no more problems. They each run flawlessly and never even care where the tank is located. It is a shame that there are no longer any in production two strokes in this size(61 to 90) available.

Many of us have been the YS route and choose not to go there again. Some of us, like me, are hard headed and keep going back anyway. I'm down to one YS .60 SE short stroke engine, with no plans to increase that amount. They are great when they run right. They can be miserable when changes have occurred in the design/parts that you or no one else still living knows about. Ditto OS pumped engines. I haven't had a problem with Enya geared pumped engines because they do not rely upon a silicone diaphragm that wears or tears from old age or being doused in an improper solution. Don't ask.

Were I a young'un with lots of energy, YS would be mandatory. But I'm a geezer that would rather spend his time snoozing in front of the TV periodically than chasing down extinct engine parts, praying that they will be available, the correct part and within an affordable amount.

Ed Cregger

The YS diaphram is used on present day four-stroke engines and is available from YS Parts for about $2 to $3 as I recall. I bought a couple as spares as there was discussions about them getting old and wearing out. I haven't used one of my spares yet. They are simple to replace, if necessary, and are still available. I even asked Richard at YS Parts if I should buy a few more so I would always have a spare. He said not to bother as it was a commonly used part in several engines and would be available indefinitely. I'm not trying to push YS two-strokes. Just like religion and politics, everyone has an opinion. But I do think in Vince's particular application, the YS 61 would simply solve his problem. There are still new YS 61s that show up and the only part that could possibly need attention would be that $3 diaphram.

If you knew just how many times I have heard that over the decades. For me, there are simpler solutions that do not introduce additional problems.


Ed Cregger

Hé airbusdrvr,

What did you do with all these motors you talked about before you bought these YS 's.
Because I have a lovely home for all these unwanted motors.
Two pictures off two of them, left by there owners and never one dead stick with me.
7,5 ccm MVVS on my video Jonni and the second a MVVS 10 ccm on the Taurus.
Third picture the datalogger on the Taurus to measure the motortemp during the flights.

Taurus Flyer

I sold a couple on eBay. I still have a used and very new OS 91 FX. I have a Cline Proportional Contol Fuel System. Make an offer.

Airbusdrvr

I am only interested in really unwanted glowplug ignited gravity compensators. You think your's is still wanted!

Taurus Flyer