freeonthree

My Feedback: (1)

Thats why I used toothpaste, it all looks so delicate. I will try the eracer next time though.

RC Specialties

W8ye,

Thanks for the information. I was wondering whether it would cause an intake restriction on the 1.00 due to the smaller diameter. I think I will give it a try.

Jim

RVM

Yeah, I am not going to polish the valves or the valve seats. If I send this off to Horizon it's going to be a pain to get them to repair or replace it under warranty as it is. If I go lapping the valves or valve seats I've got no hope.

I was thinking about just taking it to the field today and flying it to see what happens but I can't keep the engine running long enough for me to feel comfortable with it in the air. I'm going to be working on it this morning, but I'm not anticipating anything different. I just checked it and sure enough, there is very little compression. I'm going to pull the valve covers off today and snap the valves a few times and pull it up into the head with some pressure then see what happens. I'm not going to do anything that requires disassembly at this point.

I really need to fix my test stand.

RVM

It wouldn't start because it had no compression at all. I couldn't even find the compression stroke turning the prop around by hand. When it cools down it regains a bit. Then, sometimes, it doesn't get any worse after running for a few minutes. There is still plenty of hissing from the intake and exhaust manifolds regardless of whether it is warm, cold or otherwise.

Yeah I've done that, and Dave already cleaned 'em up real good. It ran fine for him. I am at a complete loss as to what is going on. The air here must be toxic to this paricular Saito or something.

RVM

Well, I ran the engine for a good 20 minutes this afternoon. It seems to have improved slightly. It doesn't leak all the compression within 2 seconds. Rather, it is taking around 5 seconds now. I'm going to go to the field and see if I can keep it running. If a couple more tanks through it (barring it dies in midair and the plane crashes or something) doesn't improve anything it's off to be looked at.

Thanks for all the advice and help so far!

proptop

My Feedback: (8)

Just to clarify something...
When I am talking about using the cleanser and oil mixture, you are not necessarily "lapping" the valves...you don't have to do it for more than a few seconds to knock off the pounded in flake of carbon or whatever...and, chrome is not THAT delicate...it's very hard and will take a few seconds of "cleaning" but not a lengthy "lapping" with a coarse cutting compound.

Another thing...you need to be careful which type of eraser you use, because the gray "pen" erasers can be a LOT more abrasive (coarse) than a Comet / Bon Ami cleanser and oil mix. And the eraser does nothing to clean the seating area on the valve face.

You just need to be "touched" [sm=bananahead.gif]...er..I mean you just need a delicate "touch" that's all...[sm=thumbup.gif]
You are just twirling the valve stem between your thumb and fore finger...


Edit: Just had a thought (ouch!) do you suppose it could be slightly warped valve(s)? They might be only slightly deformed or defective when cold, but that gets more pronounced when they get hot?

RVM...if you get tired of it and want to dump it, let me know, aye?

RVM

Two flights, one deadstick. I tried a few different fuels at the field with no difference. It sags and surges a lot, particularly on uplines. That would tell me it is too lean except for the fact it's got a pressure regulated fuel system so the fuel flow doesn't change. I richened it up anyway and it still sagged and surged. The fuel system will hold pressure for days, so I know it doesn't have any leaks.

The only thing I can think of that might not be working right is the regulator. It's still leaking a bit of air between it and the carb, but I didn't have these problems before and it was leaking then. It had the same problems on the test stand without a regulator anyway. Also, it doesn't explain the valve problem. At least Iron Bay is replacing the unit for me.

I've got a blowtorch that would not mind going on a date with some aluminum...

freeonthree

My Feedback: (1)

Have you removed the HSN and blown fuel thru the inlet nipple on the carb yet ? Probably a silly question, that was probably done as soon as the problem started...

RVM

Yeah I did that a long time ago. I fly on a dirty field so anytime I ever have any kind of engine problem the first thing I do is clean the carb and needle valve. Believe it or not this is rarely ever a real problem.

RVM

Unfortunately the November notes were the last addition Bill made. Not too long after this his home burned down and then he passed away.

I have thought about trying to continue to keep the Club Saito roster going, and keep the Notes updated, but unfortunately I don't have the knowledge or experience to fill his shoes.

NM2K

My Feedback: (14)

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Just a guess, but I would shorten the fuel tank intake line a bit. It could be that the fuel tank clunk is intermittently contacting the rear of the tank and shutting off fuel flow in little time segments, if that makes any sense.


Ed Cregger

blw

My Feedback: (3)

Jim,

I have the same velocity stack on a .72, .82, and 1.25. Is that what you were saying with that part number?

w8ye

My Feedback: (16)

Barry,

don't know which "Jim" you are talking to but it was what I was talking about.

Jim

RC Specialties

blw,

I was inquiring about the use of that stack on the 1.00. Thanks for the input.

Jim

RVM

The clunk, at its farthest, is about 3mm from the back of the tank. I checked that. The fuel system has been working fine for months. I just replaced all the fuel line and it held pressure overnight with no leakage.

That said, it's a good idea, and worth double check. Maybe I didn't measure it right the last time I did it. Thanks!

blw

My Feedback: (3)

W8YE,

It was to you. I didn't catch that the question was about Jim's question on the 1.00.

rg

Has anyone had a problem with the exhaust manifold breaking on Saito 91's it's the angle one not the fully threaded straight one. I have 1 Saito 65, 5 72's, 2 100's and 2 125's plus the 91 and it the only one which breaks the manifold I have now broken two both in normal flight.

w8ye

My Feedback: (16)

Vibration is most likely the cause of your problem on this one engine.

Did you balance your prop?

Jimmy Hoffa

My Feedback: (3)

Also check the spinner (if it has one) for balance.
Phillip

scratchonly

I have glued an aircraft ply wooden washer to the back of a wood prop that was too thin I make them with a 1" hole saw. I have also made spacing washers for behind props made from 1/32 aircraft ply with 340 wet and dry sand paper glued to both sides of the washer. I've used these on wood and composite props.

scratchonly

You can affect the hi side with the low speed adjustment. Trying for a low idle, if you lean the low speed too much it will prevent richening the hi speed enough and it could heat up.

freeonthree

My Feedback: (1)

Some Saito's will idle very smoothly (no lope) while others like the 72, idle like they have a big cam. I believe it's mostly in the carb they used on a particular engine. My friend had a 65 that would idle at 1800-1900 rpm all day long, then the carb got munched in a crash. He bought a new carb, and now it won't idle below 2100 dependably. We really miss that old carb. lol He use to land and shut the reciever off and let that sucker sit there and idle as we all watched in amazement waiting for it to load up and die, but it would just keep idleing away until he shut it off. I'd love to buy a whole bag of those particular carbs. My 65 (picked up for $60.00), idles good, but not even close to Greg's old marvel... That 65's idle was rather famous in these parts, but now it's just a memory for us all.

scratchonly

Can you support the muffler in some way?

krop

My Feedback: (19)

Jim,
The weather broke nicely and it was 65 today.
So, I ran the SAITO 82A with a stock muffler and the Turboheader.
Omega 15% is the fuel.
Idle Hi Speed
Stock 2200 rpm 7800 rpm
Turbo 2100 rpm 8000 rpm
Turbo with
new bafle 2100 8125 rpm.
The sound is even better. A truly awesome combination.
Thank you very much.
I'll keep you posted.
krop

N1EDM

My Feedback: (2)

Thanks for confirming that, RVM

Bob