Rudolph Hart

I'll second that!..slopoke?

earlwb

I have twin Saito FA40a engines on my P82 Mustang plane. it flies really well with them too. It doesn't need much of a takeoff roll either.
I'll get a video of it the next time I go and fly it.


Although they aren't Saito engines, I also put on two cute OS FS26 Surpass engines on my Twinstar plane.

mike early

wonderful!

w8ye

My Feedback: (16)

Earl, good planes, enjoy

mike early

How common is an intake leak at the o-ring? I've never had one. What are the symptoms?

blw

My Feedback: (3)

Mike, it is a common fault with 72's that have the old style backplate. Sudden and/or intermittent lean conditions are the most common symptoms. There was a mention or two of this happening to the 82.

mike early

Thanks, this particular engine is a .91 that I bought used. It has the metal throttle arm. I will replace that eventually, PITA adjusting the low end in a fully cowled engine. Maybe I could glue a very short piece of fuel tubing on there to help center the screw driver.

Anyway, my problem is that the idle hangs for a while before settling down to normal. It's a high pitch prop and I need it to slow down on landing. Any suggestions?

Rudolph Hart

Hello mike,i've just bought about 30 o ring and gasket kits for all the saitos i have,they are quite cheap.Stripped one of my 82's last week and gave all the old o rings and washers the flick.The old o rings were flat and hard,you would'nt believe what the washers looked like it's something i'll be doing more than once every two years or so now!

blw

My Feedback: (3)

Mike, I like cowled models. Using a long jewelers screw driver thru a small hole in the cowl works well. You soon get a feel for the lsnv screw.

FNQFLYER

This business with the plastic back plates warping and leaking.  While not on a Saito I have had a similar experience with a 2 stroke and I did a field fix (at  comp a long way from home) of acquiring a tube of RTV 506 (orange) put a good bead of said sealant around the mating surfaces and then bolted them together, them cleaned the excess of with initially a rag and then when dry a sharp knife.  That was 2 years ago, just sold the engine and the back plate is still in place with no leaks. 

Sharpeye22

I am confused,
I thought it was leaking around the intake manifold where it enters the engine, I also thought it did not matter if it leaked around the backplate since that area was vented anyway.

w8ye

My Feedback: (16)

The plastic back plates warp, get soft, and flex. They let the intake manifold move in and out of the head.

The intake manifold starts leaking where it goes into the head as the o-ring wears out.....

Hobbsy

My Feedback: (102)

Good morning Jim, did you notice the ad above about the 2.00 triple being out?

slopoke

My Feedback: (16)

Yeah they do sound good, but I'm still tuning them. Hope to fly today.

One of the guys at the club has a B-17 With 4 Saito 40's. They really sing.

angel18

Yeah.....weekendi'm have a long timed to play....

blw

My Feedback: (3)

The 82 new style metal backplates slipped again, and missed the April ship date as originally promised.

w8ye

My Feedback: (16)

I see it is the old 170 with 72 jugs instead of 56 jugs on it.

Rudolph Hart

And it's supposed to be lighter?? you tube has some good vision and sound with a 200 bolted to a fockewulf 190,enjoy

w8ye

My Feedback: (16)

http://www.youtube.com/results?searc...0&oq=saito+200

[youtube]http://www.youtube.com/watch?v=Ld88cJgf2XI[/youtube]

[youtube]http://www.youtube.com/watch?v=FEtbDsBTg4g[/youtube]

FNQFLYER

That RTV I talked about also takes care of the warpage experienced by these plastic back plates as well as sealing them.  It is also oil and fuel resistant

mike early

besides the plastic back engines, intake leaks are very rare?

Rudolph Hart

I'd like to see some photo;s re the plastic backplate issue,preferably while the plastic backplate is attached to the engine as i expect the engine to look red hot in the pic,and i really mean red hot plural.I have no issues with the plastic backplates on mine apart from flat old o rings and maybe a stripped thread or two.I tighten mine up till it strips then back off a quarter turn

earlwb

If I remember right, the plastic backplate allowed the carb and intake manifold to move a little more causing the O-ring seal in the intake manifold to wear out faster too. I think the guys with the profile 3D planes tended to have the most trouble with it as the vibration was higher in those types of planes.
a old thread about it here http://www.rcuniverse.com/forum/m_9013675/printable.htm
another thread, where someone was making new aluminum backplates before Saito did so to fix the problem.
http://www.rcgroups.com/forums/archi.../t-993891.html

mschulz531

I have a Saito .72 that was given to me because the previous owner had nothing but problems with it and was so frustrated with the operating characteristics of the engine that he would no longer trust his plane with it. I took it, did some research (including finding this forum!), discovered the problem, ordered a new backplate and some new carb screws, put the engine back together, and fired up the engine on a test stand. The engine runs great and will be installed in my GP P-51 .40 size plane that I built from a kit last winter. I can't imagine why Saito ever designed a plastic back plate on any engine; as for me, I'll trust the newer aluminum back plate over a plastic one any day.
-Mike

earlwb

I think the plastic backplate would have worked Ok, if the carb wasn't mounted to it as well.
On those 2 stroke engines with plastic backplates, they didn't have any issues with them.
That was probably what got the Saito bean counters to think they could save some money there with a plastic backplate. It also likely worked OK with limited testing too. But when it got out into the real world is where all the problems started occurring.