Question about LA-S OS in FS

LAST EDITED ON May-12-04 AT 04:53 PM (CDT)
 
My kid replaced the OS-40 in his Flite Streak with an OS-25 LA-S. He says he can't get the motor to 4-2-4. Is that smaller motor supposed to 4-2-4 or should it be 2-stroking away the whole time?

Cheers,

Andy,

A good friend is using 25 LAs on a couple entry-level CL models, including a Flite Streak ARF, and he pretty much sets the needle to just pound around in a constant two-stroke.

The setting does of course vary somewhat depending upon what the model is being asked to do, but what is referred to as a "wet" two-stroke is the closest his engines ever get to breaking into a four-stroke.

I think he is using APC 10-5 props, not certain of this. What is known is that he is using stock muffler, stock remote NVA, the motors are completely stock, 4-ounce clunk tanks assembled per factory-supplied instructions, muffler pressure.

Just puond er; around with a 9/6 or 9/5 zinger prop!! Take yer pick!! Those grey apc props have been proven to be garbage, in case you havent heard!! Paul

9x6 is way to much prop for the 25LA. Run the APC 9x4 and let it eat. APC are great props, I've used them for years without a problem.

Geez, Paul.
I wouldn't say that APC's are garbage....although there are some flaws (of late?) with the center holes. The APC's that I have fooled with all have a constant pitch (meaning that a 10X4 purchased today seems to have the same pitch as one purchased three or four years ago) and almost NEVER need balance. I have about 3 dozen of them in my field box (I try to help folks get the right prop) and all have the center holes drilled so that the tips are the same distance from center, and all are balanced well enough that only minimal sanding was required.

My guess is that Howard, or someone else that they know, has contacted them about the drilling issue, and that the folks at Land are rectifying the problem.
They will continue to be the non-carbon prop of choice for me, and for lots of folks that I know.

See Ya

>Just puond er; around with a 9/6 or 9/5 zinger prop!! Take
>yer pick!! Those grey apc props have been proven to be
>garbage, in case you havent heard!! Paul

WHAAAAAAAAAT !?!?!?!?

Use a 9/4(almost any) or even an 8/4 and the OS muffler. It will run anywhere from a solid 4 stroke to a solid 2 stroke, depending on the needle setting. Even 4 stroking on an 8/4 it will have more than enough power for a Flite Streak.

Yes your right peabody and freinds, I jumped the gun on this one!! And the 9/6 i mentiond ws a typo, i meant to say 9/4. And as for the 9/5, someone told me they liked it that way. Peace-- Paul

I checked today and Rick is using APC 10-5s on his 25 LAs. One of the 25s is fitted to an ARF Flite Streak, the other is installed in what was originally a Top Flite Tutor, a mere 25 years old.

The Tutor got smacked pretty nicely at the Helmick-sponsored Trim 'n Compete weekend we had last year at Arlington, WA, and as the wing was not damaged much at all, Rick built a new model around it.

The point here is that he likes the motors, even though one is powering a flap-less ARF, the other is having to deal with not only a heavier model but one with flaps as well. And another 25LA is destined to power his abuilding Oriental from a Brodak kit, this having been a prize I won at a contest last year.

So while I continue to be less than impressed with the raw power of 25 LAs, they appear to work quite well in a wide variety of applications, are readily available for not much money, are not fiddly at all.

We did try a couple Real Deal B-Y&O 10-5s. At first Rick thought he had better line tension, but after a couple more back-to-back flights he changed his mind and what with the wooden props not being available went with the APC numbers.

Incidentally, I have in the past made him try an APC 9-4 a couple times. Didn't like it, although I cannot remember why.

Thanks for all the help, guys!

Sounds like a 9/4 and fiddle with the tuning!

Cheers.

Dan,

I have a number of 25LA's and a couple 25FP's and I have to admit the FP seems to have more power. However, that being said the 25LA has more than enough power and is a great Fox replacement in airplanes weighing 32oz max. I have tried the 25LA with a 10x5 APC and in my opinion the 9x4 is a way better choice.

Bottom line is you can't go wrong with the LA's or FP's!

>Dan,
>
>I have a number of 25LA's and a couple 25FP's and I have to
>admit the FP seems to have more power. However, that being
>said the 25LA has more than enough power and is a great Fox
>replacement in airplanes weighing 32oz max. I have tried the
>25LA with a 10x5 APC and in my opinion the 9x4 is a way
>better choice.
>
>Bottom line is you can't go wrong with the LA's or FP's!

I have to hope you are wrong as to the 32-ounce maximum weight. While Rick can in fact build light, he began with a stock kit; I see no chance at all of having his Oriental come in at less than 36 or 37 ounces, see 38 to 40 ounces as more likely.

On the other hand, my still-new Skyray 20 (35) is 34.5 ounces and the box-stock O.S. 20FP has yet to notice the model came in about 2.5 ounces heavier than I would have preferred.

With that in mind, plus the ever-present option of hitting his 25LA with more nitro, I don't think there is a problem.

Agreed about the APC 9-4. Universal *good prop* for 20s through 25s, I still don't understand why Rick didn't like the one I made him use.

Also agreed on the 25 FPs and LAs. Remarkable motors. Wish I had paid much closer attention to what Brett was saying five years ago as it related to the 20FP.