freeonthree

My Feedback: (1)

I just used carb cleaner from Napa. If you want to do that, remove the glow plug, and keep the engine inverted. Remove the valve covers too. I'd spray a bit, then turn the engine over, then spray some more and turn the engine over, and do that for about 1/4 to half the can to be sure its all spotless. Then put some oil in the glow plug hole and turn the engine by hand before running the engine.

freeonthree

My Feedback: (1)

I forgot to mention, remove the carb and exhaust, and spray mostly in the ports. Blah... you probably knew that already... I have a tendancy to over explain stuff sometimes.

RVM

It's worth a try. I don't have a Napa here but I do have an AutoZone. I'll go see what they have.

I'm not going to pull the carb off. I'll just spray a bunch into the intake manifold and let it draw in. I'll also put some into the cylinder through the glow plug hole as well.

Should I turn it over with a starter or just by hand?

freeonthree

My Feedback: (1)

Huh ? Props arn't threaded... They just slide on and the nut and washer hold it. Sounds like your not tightening the prop nut sufficiently. Put more wood to it !

Astrodog

RVM,
By stripped I mean the back of the prop has been cut where the knurled flange on the engine holds to the prop. It is cut deep enough that I cannot tighten the prop enough to fly.
Thanks for the quick reply.
Astrodog

freeonthree

My Feedback: (1)

Any carb cleaner will do, Autozone is fine, and just get whatever is cheapest. I'd turn it by hand, and keep the engine inverted. You'll lose all compression for a while as your doing this by the way. All kinds of crap will get into the valves as it washes out. And make sure all the carb cleaner is outta there before ya fire the engine. I'd also hold the engine so any cleaner that got into the crankcase could run out thru the vent nipple after your done cleaning too. Also, make sure you do have valve clearance by just wiggleing the rockers by hand, just to be sure... always double check everything 15 times, I do... lol

Astrodog

Freeon three you're funny.
As I explained in the last post the back of the prop is chew out until it will not tighten more.
Thanks for the reply
Astrodog

rlmcnii

My Feedback: (3)

nismoserspecv,

My .91 runs very well on a ProZinger 14x6, a 15x5 loads it a bit too much. I tend to favor props with a mid-range pitch, 5"or6"; and, tend to like wooden props. Yes, i know they are not as good as nylon, plastic,or composite.

Saitos require quite a bit of running to get them fully broken in; be patient. Also, it is probably not worth worrying about a couple hundred rpms at idle, unless the plane will not quit moving on the ground.

I have no experince with the .65, but agree with the previous poster who said that the .91 is a nice, smooth engine. Actually, the .91 is the final evolutionary development of the .65.

Tune your Saitos well and they will be a pleasure to operate.

freeonthree

My Feedback: (1)

No ! It's only a couple of screws and 2 O rings ! Remove the carb and the exhaust, spray out the ports directly ! Part of the cleaning is done by the pressure of the spray, like a pressure washer. It blows the crap off. First spray some in there and get it all wet, then after 30 seconds or so, blast it good. Then let it sit for 30 seconds, and blast it again, and do that until it all look like brand new in there, and remember to rotate the engine alot during the process too. You want to blast the cleaner into the ports while the valve is open mostly, so do each side while the rocker arm for that valve is in the down position.

DON'T FORGET TO WEAR EYE PROTECTION ! Just had to say it...

freeonthree

My Feedback: (1)

Thats because either the prop slipped, and ground it down, or the collet got pushed back too far from overtightening, or the prop is simply not thick enough. I bought a wooden prop for my 56, but it's alot thinner than the master airscrews im used to, and I had the same problem.
I still have that useless to me prop for some reason. It wont get tight on any of my engines, so im pretty sure my collets arn't pushed back too far on all of em. lol Once a prop gets loose and slips, those teeth on the front face of the drive piece, just grind the prop away fast. I'd say try a new prop and tighten it better. They gotta be tight ! And make sure there's not a bunch of prop material between the teeth of the drive piece. Is that called the collet ? or is the collet the little tightening piece that slips into the back side of that piece. I don't know what that drive thing is called. "Collet" I think

nismoserspecv

Thanks all who have offered help. I will get off work soon and then work on the saito's abit more before flying tomorrow in the 80'degree weather that has final came! Yes if the wind is right the H9 Hell Cat powered by the YS1.10 and the Taxi Cup II powered with the 65 saito will fly for the first of many flights. As for the 91s GK it will need a prop chance and its back to the skys on the Fourstar 60.

I will let all know and post Pics on Monday.

Have a great weekend and thanks again.

Pit-Viper 1

My Feedback: (12)

Something we did on my friends .72 after very poor idle problems. He took the motor apart and and removed the valves, then we used powdered graphite and sprinkled it fairly heavy in the area where the valves seat. Then he reinstalled the valves only and connected a cordless drill to the valve stem and lightly pulled the valve so it was seated and spun them for about 30 sec on each one. Powdered graphite is a neat little product mostly used for lubing, but it actually adheres to the metal and fills the pours. It ran great after that. Worth a shot if you are going to have it apart.

Shane

Astrodog

Freeonthree,
Thats what I think the problem is. I think that the prop is too narrow front to back. I did see the thrust washer for the YS engine an I wondre it there is something for the Saito engine or if the the one for the YS will work. I have my doubts it will.
I really don't want to put a spinner in my big H9 120 Stick but i may have to if I want to use the apc props.
Thanks
Astrodog

freeonthree

My Feedback: (1)

I had to lap the valves on my darn 72 also. It never idled right since new. I used it that way for years though. Now that the valves seal good, it idles with a slight lope, but dependably at 2300 or so. I kinda like the lope !

freeonthree

My Feedback: (1)

Here's what ya do, just find a washer, any washer, that has the right size hole in the center for the crank, it doesnt need to be any larger in diameter than the prop nut really. Put the large prop washer on, then the extra washer, then tighten the nut. It will work great ! I can use this wooden prop I have if I do that too, but I decided I don't like wood props. I love the Master Airscrews !

Astrodog

Thanks freeonthree
astrodog

freeonthree

My Feedback: (1)

I forgot to mention, if ya have the weird double nut stuff on there still (I use the acorn style) your going to have to get a prop washer that fits the crank snugly first.

Pit-Viper 1

My Feedback: (12)

You can also use a piece of leather or emery cloth on the backside of the prop. This is what they recommend for YS motors due to backfiring and stripping the flywheel and backplates. With the emery cloth I believe you use the gritty side against the back of the prop.


Shane

RVM

I couldn't get the .82 to start at all. It would pop the prime but would not keep going. I left and bought a bottle of carb cleaner and used half of it in the engine. Compression neither increased nor decreased. I rinsed the engine with fuel and tried to start it. Nada. I hooked up my electric starter and gave it a go and that finally got it going. I was able to get the lowspeed needle adjusted where it has a relatively smooth idle around 2100 RPM. Transition isn't great but I haven't had a chance to really tune the highspeed. I let it run around 3000RPM for about 5 minutes. Out of curiousity I then picked up the plane and rolled it inverted (putting the engine in an upright position - it's installed inverted) and it lost RPM and died. The RPMs were fine while I held it vertical, just not with the engine upright. The regulator is working properly so fuel flow isn't the issue.

I went to flip it by hand and it started after a few tries. Then it died. I can't get it started by hand anymore - it has to have the starter.

It moderately surges at any and all throttle settings. Fuel flow is fine. Glow plug is brand new Saito (thanks Hobbsy!). There are no air leaks anywhere.

Compression is gone right now. Literally gone. I can't backflip it to start it, or turn it through compression to start it because I can't feel the compression stroke. At all. zilch, nada. I imagine once the engine cools off it will go back to its valve hissing state.

It runs very smooth (except for the surging) in the middle RPM range, say 3500RPM - 7500RPM. Is compression less critical in this RPM range? It seems to make sense that it would be.

The valves are pretty clean. I looked through the ports at them and what you could see was a little varnish, but bright silver rings where it seats. I don't think there is crud or build-up blocking them. I have no idea how Hobbsy had good compression when he had it. Maybe something in our air down here?

The valve clearance is still at .004".

This is all pretty much what the engine was doing yesterday.

I'm going to fill the cylinder with carb cleaner and let it sit inverted overnight and see if that solves anyway. I don't anticipate that it will, considering the copious amounts I just put through the engine, but we'll see.

By the way, I'm doing this all on my plane because the vibration from the engine while I was trying to get it set up (before I sent it to Hobbsy to look at) destroyed my test stand. It stripped out the screws holding it down.

Now the vibration has just about destroyed another set of crappy nylon gears in my 811 servos. *sigh*

I hate this engine.

RC Specialties

Hobbsy,

Just completed the test on the Saito 1.80 TurboHeader and thought I would post the results. The in flight audio is already out there. It has a great tone.

Ambient Temp: 85 Degrees
Prop: APC 16x8
Fuel: Cool Power 15%

Stock Muffler
Peak RPM: 9200 RPM
Idle: 2300 Steady
Noise: 92 dcb at 10 feet.

TurboHeader
Peak RPM: 9450 RPM
Idle 2250 Steady
Noise: 100dcb at 10 feet

Jim

freeonthree

My Feedback: (1)

If it cools, and you get the compression back, I bet your running it too lean and overheating it, or you simply don't have enough oil in your fuel or something. Im stumped beyond that without it here on my test stand. It shouldn't vibrate that huch either. Has that engine ever been in a crash ? fallen from hanging position in the house or anything like that ? Ya know, if it's vibrating badly, it may even be foaming the fuel. New props are not balanced from my experience either, there all way off, and that can cause alot of vibration. Hey, if ya think your having fun now, try a heli ! 10 times the moving parts ! Is your tank center line at the center line of the carb ? Im suspecious of the funny running when ya rotate the plane...

freeonthree

My Feedback: (1)

Since it ran good for Hobsy, I think you have a funny fuel causing the engine to run real hot, at least that what it kinda sounds like to me. See if it does the same thing if ya run it real rich, and of course, start off with the engine cool. Open the LSN 1/4 to 1/2 turn, and the high speed about 1 turn richer and try it. Man, im running out of idea's here. If it has compression when it's cool, it's definently getting way too hot.

TimC

It could be a crack that is getting larger with the heat. Is the hissing definitely coming from the valve seats? I had an aluminum intake manifold that was cracked and when hot, the crack would open up enough to where the engine wouldn't idle.

RC Specialties

Guys,

It if was running good before for Hobbsy, you should not have to adjust all the needles testing it. If it is hissing from the valves then they are not closing for what ever reason. RVM, make sure the valves are adjusted to .004. If it is running hot richen the high side alone. The low side is not causing it to run hot at WOT. It sounds like the valves are adjusted too tight and it is way too lean. Start with the right valve adjustment and 4 turns out on the needle valve. Then start you adjustments from there. Go back to basics.

Jim

Hobbsy

My Feedback: (102)

Tim, on the last run I did, I ran it at 7,500 rpm for 16 oz of fuel about 22 minutes and it ran pefectly. So.