Ken6PPC

No problem here! You are right that needless disassembly is more likely to cause harm than good. However, if Rexracer finds that he has the old style backplate, at least he will know what to replace it with - IF it needs to be replaced!

In any case, I'd certainly try running it first to see how she goes!

tailskid

My Feedback: (34)

Anyone know the bolt size of those machine screws that hold the backplate on a Saito 100? I know it is metric, what what?

Hobbsy

My Feedback: (102)

M3 I believe, I'll use a screw checker tomorrow if no one answers that tonight.

tailskid

My Feedback: (34)

Thanks Hobbsy

w8ye

My Feedback: (16)

To my knowledge all the 82's had the new style back plate.

But, I have seen new style plates on 72's that were bad.

The intake tube is different on the 82 abd they are generally not subject to trouble.

rexracer

My .82 definitely has the new style backplate. I'm still going to take it off, though. Running it right now is not really an option since it's 15 degrees outside. Too cold for me, and probably too cold to try to start this thing. I am a little worried about this engine. Even though it turns fine and has compression, there are a few things that bother me. I tried to get the backplate off, but it was stuck. there are signs of melting on the top by the cylinder. At first I thought it might be some silicone or gasket goop on the top of the backplate, but it's definitely part of the backplate. If you look at the engine from the back, the apparent melting goes from about the 11 o'clock position to just past the screw at 2 o'clock. The backplate is stuck in this area, so I have a disassembly question. With the screws out, can the backplate rotate in the case? If so, I may be able to loosly clamp it in a machine vise and rotate the engine to pop it loose. Whoever had it before me also decided to slot the top of the high speed needle with a hacksaw, and hacked into the set screw for the needle extension. [&o]

Capt Lou

w8:

I have a new Saito 100. What is the benefit to putting a velocity stack on this engine? Also, if I were to put one on my engine, I probably would use an air filter (such as the Bu Line), do you see a problem with this?

Thanks

Capt Lou

w8ye:

I have a follow-up question to my velocity stack question. I notice that every new Saito engine (.65, .72, .91S, 1.00) I buy the carburetor is affixed so that the needle valve adjustment is on the right side of the engine (as you face the front) coming out under the exhaust port, and the the servo linkage arm is on the left side. This set up seems akward to me as to adjust the needle valve while the engine is running, you must maneuver around the exhaust pipe. The first thing I do with a new engine is reverse the carburetor to avoid this. My question is, am I missing something that Saito intended by using this design? I will continue to reverse the carb unless I find that I am doing something wrong.

Thanks again

blw

My Feedback: (3)

Rexracer- They didn't need to hack the hs needle as you can loosen the set screw and put in a wire extension. I always use the Allen wrench that comes with the engine. As far as I know. all .82s came with the newer style backplate. It looks like a good idea to order a new one for your engine. They are around $6, and it sounds like you need one.

Lou- The stack helps prevent excessive fuel spitting out of the carb. I had an engine that began doing that and the stack cut the problem down a lot. There may be a slight benefit of helping fuel economy. The carbs are easy to reverse, but I've not done this on any of mine yet.

w8ye

My Feedback: (16)

Lou,

You are not doing anything wrong by reversing the carb.

Both OS and Saito ship the engines new with the carb this way. It makes the engine more compact.

Some planes it works out better to have the lever on the left and others on the right.

rexracer

BLW,
That's why the needle hack made me mad. It's so unnessasary. I'll probably buy a new one and put a 2-56 allen head machine screw in the extension hole. That way I can use an allen driver thru a hole in the cowl, but the cowl will still come right off with no interference. I'll get a new backplate, too, if I can get this one off.

w8ye

My Feedback: (16)

Rex,

Due to vibration, you'll never be able to get the wrench into the socket with the engine running.

Capt Lou

blw & w8ye:

Thanks for the responses and information. I'll continue to reverse my carbs as I find this to be a better position to adjust the needle. I also just ordered from Horizon velocity stacks to try on my .91S and 1.00. Thanks for the good information.

w8ye

My Feedback: (16)

It is with pleasure that BLW and I are happy if you are happy. Your choices sound good.

Don't forget the O ring that goes between the velocity stack and the carburetor. You can use an old manifold O ring or buy one from the hardware store?

Tripp2loo

My Feedback: (15)

Prop Question for anyone.

I have a Saito 150 and a 182TD both in scale biplanes. The maximum prop recommended, is 18x6 for these engines, but this prop is really too small for the scale of the planes. The engines are plenty of power, and fly the planes well, but just look too small.

What are the issues and risks if I used 20" props?

Cheers.

Hobbsy

My Feedback: (102)

The backplate screws are M3 with a .5 thread pitch.

JNorton

My Feedback: (2)

Real simple think of it this way. You have a ten speed bicycle. It looks better to you with the gear shifter straight up. However the gearing is now in 8th gear and you are stopped. How easy is it for you to pedal the bike? Do you overheat? What happen to the performance of the bicycle? Over propping an engine is exactly the same.

Use a display propeller for static and the correct prop to fly it. You'll be much happier so will the Saitos.
John

w8ye

My Feedback: (16)

The 18-6 itself is a little big for these engines but should fly a Cub type plane fine.

rexracer

The good news is that I got the backplate off my .82 and everything inside looks pretty clean. I found out why I was having trouble getting it off. It was melted and there was a lip on the inside of the case holding it on. Has anyone seen anything like this, and do you know what might cause it? It obviously got pretty hot.

w8ye

My Feedback: (16)

Looks like you had a crankcase fire

If the crankshaft was rubbing it would be burned where the crankshaft goes around?

rexracer

Crankcase fire? Does that happen? There is a slight swirl mark from the crankpin, and the melt looks like it started from touching a hot crankpin at TDC, but the crank and rod look fine. I just finished making my new test rig, so hopefully it will get up to 40 degrees or so next week when my new backplate arrives and I can start her up. I'm planning on mounting my test stand on slides with a digital scale to get thrust #s. Should be fun!

w8ye

My Feedback: (16)

Well, no use going on a witch hunt. Put it back together with the new parts and see what you got.

Your test stand seems exciting. Try some different props and give us a report

Jim

rexracer

Just got another package in the mail! This one's an FA-45. I'm hopeing to get some info on this. Does anyone have a PDF of the manual? I know it's discontinued, but I believe Hobbsy said it shares some parts with the .56. Any chance I could get a list of some of those parts? Any help, info would be appreciated. The only thing I can see wrong with this one is a slight dent on the intake tube. The guy I got it from says it runs great, and he ran about 1/2 gal through it last summer. It's a little oily and smells like fresh glow fuel, so I think it's all good. I think I'm gonna be busy this weekend...I even have a 12-5 prop to try on it to see how it compares to Hobbsy's FA-45.

w8ye

My Feedback: (16)

I think there are some different models. There is a 45S that looks just like a 50 or 56.

All the 45's I've seen looks like Hobbsy's and I think they are called the MKII. I've probably seen a dozen of those.

The MkII has a different cam/cam box than the 45S. The intake manifold is also different.

rexracer

This is the MK2