FNQFLYER

The flywheel effect is best used with slow running engines that you want to extract the last drop of fuel with.  It does help start and run the engine but the advantages gained are not worth the extra wear you impose on the engine.  We use big props in Texaco fr just that purpose to extract every bit of the fuel allocation but step down in size for duration (a speed event) so choosing something in between is probably the best way to go

rebranger

Plastic - nylon props have a longer life, no doubt, and wooden props splinter &/or break easily. MY experience with Saitos is that the crankshaft is "soft" or malleable on the outter (prop) end. If you know how to deal with a bent crankshaft, run a plastic. If you can't straighten a shaft or pay to have it done or have plenty of $$ to waste, run a plastic/nylon. "Pay me now or pay me later"
I never run a plastic/nylon prop. Wait until you hit something (ground, fence, hand, fingers, glow driver, etc) with a plastic/nylon. Those props are tough, hard to break. The shaft or fingers will go first!! Props are cheaper than crankshafts, which are cheaper than fingers. Ever try to built & fly a plane with 4 digits, & one hand?

Rudolph Hart

Hi huk i think w8ye mentioned a while back that the 125's don't have them for some reason but most of the engines i have do.I'd love to run wooden props and will soon.My 46 size mumbo jumbo(heavily loaded evil deccy for short)plane will soon benefit from a lighter prop up front so i can move the rear mounted battery pack forward a bit.

Hobbsy

My Feedback: (102)

On the Saitos where the barrel is located by a dedicated barrel location screw the barrel spring serves no useful purpose. Neither my little .30 nor the 2.20 that I sold had a barrel spring.

Rudolph Hart

Yeh thanks mate not sure about that i have both the engines you mention.I think the spring keeps the barrel side ways movement in the groove constant,that is,always on the same side.They are very sensitive to that re low speed tuning.

rajul

My Feedback: (58)

I received my new gaskets for the Saito 125 and 82. There are some viton o-rings which are packed separately. Where would these viton 0-rings be used? I would imagine at higher temperature locations e.g. intake manifold seal with cylinder?

SrTelemaster150

There are usually standard & viton "O" rings for the intake pipe.

The viton ring goes on the end that enters the head.

FNQFLYER

Please define "plastic".  Master Airscrew and APC aren't plastic in the true sense and as for cranshaft bending guess I have been lucky because the old crankshaft problems I have ever had have been breaking diesel cranks when using an electric starter and the engine had a hydraulic lock.  I have sustained vertical full power (one point landings) with my models right down to dead sticks and nosing over in te wind and every thing in between as I said never a bent crank.
However I have burnt a lot of dollars on speciality carbon fibe props (usually costing $50 upwards, guard them with my life) and seciality wooden.  My choice of sports prop is APC first and Masterairscrew second.  Racing is a different matter not for this discussion.
The "plastic" props I referred to were to old Tornado and KO props used mostly on control line but are creeping into some aspeects of R/C flying lately.  

rebranger

Plastic Definition: The typical MAS or APC nylon type props. It doesn't take much of a lick to get a Saito crankshaft outta wack!! I have collected a sack full of bent shafts over the years. When I run outta something to do, I can straighten most of them, but it's time consuming & tedious. Seems like they always bend right past, forward ofthe bearing shoulder. Remember, all models have an "expiration date"; I just hope I don't own them when that date arrives!! I got a Saito 120 that has out lived 5 airframes, a 180 that has outlived 3, an 82 that has survived 2, but my 100 only made it to 2! Good Luck!

flyingagin

rebranger Would you mind passing on to us how to straighten a crankshaft?

Ken

FNQFLYER

What sort of fields do you guys fly on.  There was a scale do on last w/end at a place called Rosewood in SE QLD attended by a number of POMs and Yanks who to all acounts were "impressed" with the grass field and its preparation.  Jets operated off it as did all other types of a/c (models that is).
I guess it you are operating off concrete (hard formed) strips the problem of bent crankshafts might be there, I very rarely operate of other than hard formed grass.  The strips I operate off are formed with rolled termite mounds or similar with grass laid on topsoil over the top.  Hard and as good as concrete for load bearing.
I was just talking to my flying mate (southern one) who has bee flying with Saitos for some 30 years and he has never bent a crank shaft either.  Guess you guys had better more here as an economy measue, after all we have cheaper fuel and our fields are kinder on engines (it would appear)  

flyingagin

I have yet to bend a Saito. But I still have an OS that I bent the crank on. It was pulling a control line plane.I would love to be able to straighten it.

I have visited Perth a few time (US Navy). Loved it, wanted to see the rest ofAustralia, but never got the chance. Seemed like a good place to live.
I couldn't spend much money there. Locals took good care of us.

Ken

FNQFLYER

Thanks for the compliment.  Here in FNQ I have met up with a lot of ex Yanks most Vietnam vets of various colours and persuasions and occupations.  Most notable are the Air Americia guys who worked in Laos and Cambodia etc, but they mostly have an aviation background as a common background.  Makes for interesting times when the "war stories" are told 

rebranger

Here in the Southeastern US when have a phenomenon called "rain". I spent 3 seasons, 91 -93, in Moree, Guniwindi & Towomba NSW. They said it rained the year I left!!!
We have tarmac & concrete paved strips. Also ground gets hard sometimes. Flying daily, gravity & experimentation can take it's toll! Wings fold, break, tails come off, new fangled gyros fail, disorientation,
To Straighten crank shaft:
Chuck CS in drill press or lathe, threaded end in chuck jaws, position dial indicator on front bearing race or journal, hit with brass hammer. Turn shaft by hand, note roll out, Hit A little harder, etc. That's whats tedious. After a few you kinda get the feel of just how hard to hit. Some you just can't straighten, especially a double bend, but most you can if you are patient.

FNQFLYER

Toowomba. Goondiwindi, both are in SE QLD, Moree is in NSW where the cockroaches come from, we have climate change up here in FNQ each and every year.  Re bent crank shafs, bitumen and concrete are hard on anything from rubber to metal but even with hard strips we are hard pushed to bend crankshafts but why worry at the prices you guys get them for I wouldn't worry about straightening them.
As Bob Munn once said we are blessed here in OZ with to many things to list.

flyingagin

Thanks rebranger
Sounds simple enough. Makes sense. Another use for my little lathe.

Ken

Rudolph Hart

That's itas soon as i'm done flying the deccy i'm going to kill myself

Quikturn

My Feedback: (12)

I bent a crankshaft on an OS once. I dropped it. [:@]

There was a thread I read years ago where someone offered to straighten bent crankshafts free of charge. Just cover the shipping. He had some sort of lathe setup and a micrometer to measure any imperfections. I wish I knew which thread that was.

I too was in Perth Austrailia when I was in the Navy during the 80's. Wonderful place. We took a wine tour on a boat in Fremantle. Too much fun.

hsukaria

I am told that I have a distant cousin who immigrated to Australia, but don't know where. Does that count?

Regarding bent shafts, I would consider how much I like the engine first. Then, if I like to keep it, I would buy a replacement crank. None of that *****-o-meter setup.

FNQFLYER

Don't kill yourself Old Fart, Colin and Tony need you during the year to help out.  After September you can do the deed, but first send me a list of all your modelling stuff, it might be worth a visit.
I have been reading the latest missives from the MAAA, MAAQ and te AWU ad they all sound the same but on different themes.  That combined with the change in weather lack of internal lubricating fluid causes aberations.
BTB when was the last time you bent a crank shaft on a Saito.  That being sad I am about to order a spare for each type Saito I own, Sodds Law and all that 

flyingagin

Quikturn, that wasFlyboy Dave who was fixing bent cranks.

Here is the thread.
http://www.rcuniverse.com/forum/m_69...tm.htm#6948801

But on post 347 He states he is not fixing bent cranks anymore, the very last post in the thread. That was3/24/2012

It maybe tedious, but does not sound that hard to do.

Ken

rebranger

Bent Cranks:
I wonder if metal has a "memory" ? Anybody know? Something scientific, data, tests, studies?
I think it does..sometime all is takes is one lick (hit) in the right spot & Wala! They're back straight..Go Figure??

rowdyjoe

My Feedback: (9)

Ah Ha ! My brain just engaged ...thanks to FNQFlyer. My FA-80 develops 8400RPMswinging a 14x6 Xoar prop and a Turbo Header installed. Irun 20% Power Master fuel. This engine appears to be getting stronger the more Ifly it so, maybe it's wearing in a bit more.

Checked my FA-80GKfor springs and screws and they are all there. Maybe I need to tighten the screw more. I'll have to "play" with it some more Iguess. When I installed the new low end needle in the carb, was a change in retaining screw required? It now has the new style plastic barrel. Iguess I could put the old needle back on and see if that cures the problem.

RJ

blw

My Feedback: (3)

I think he is totally out of the hobby. In any case, it was mostly a bang with a big hammer operation.

blw

My Feedback: (3)

I think he is totally out of the hobby. In any case, it was mostly a bang with a big hammer operation.