freeonthree

My Feedback: (1)

Yep, I would pull the cylinder, remove the valves, and clean and inspect the valves, springs and seats. Sounds like you got some crud in there somehow. Sounds like an hour of fun to me ! Dennis

freeonthree

My Feedback: (1)

When you checked for compression, did you have the throttle wide open ? Open the throttle up all the way, and try to turn it again. Let me know...

RVM

Wide open.

freeonthree

My Feedback: (1)

OK, I think you got some crud between the valves and the seats, or some buildup on the stems that's keeping them from closing properly.

rajul

My Feedback: (58)

I have a 82 on a profile and never had any problem with it, except for some minor oil leak from the front. I use 15% coolpower with 2 ounces of Klotz castor mixed in. Could be the type of castor or amount in your homebrew?

freeonthree

My Feedback: (1)

I think you just solved the delema... Bingo ! I bet if he removes the exhaust, he will see alot of black soot in there.

RVM

It was a pure synthetic that I added 3% Klotz Benol to.

I don't know why the valves aren't seating. There really isn't any crud on the seats and there is a shiny silver ring around the valves.

freeonthree

My Feedback: (1)

Well, lets verify that the valves are leaking. Turn the engine over and listen carefully to the exhaust and carb openings for a hissing sound as it goes thru compression. If ya hear a hiss, the valve is leaking, probably due to some crud in there.

freeonthree

My Feedback: (1)

When you adjust the valves, set them so there's no drag on the feeler gauge once. Those little valve springs are so soft, they can fool ya sometimes. If you feel any drag on the feeler gauge, you may be holding the valve open slightly. Just a thought... I always wiggle them by hand after I adjust mine, just to make sure.

TimC

RVM, if I'm not mixing your engine up with another Hobbsy worked on, he took your muffler off and ran one of his. Could there be something loose inside yours causing this problem. You might take the muffler apart and see if it's OK inside.

Hobbsy

My Feedback: (102)

Bob, the last time I ran your engine it turned the APC 14x6 at about 9,500 rpm. I checked the valve lash afterward and had to loosen the glow plug to get it on TDC, the compession is that good. Now, barring the mailman running over it with his truck or you setting the valves too tight again it should run perfectly. I ran both WildCat 15% Premium Extra and PowerMaster 15%/ 18%/syn castor lube. I ran it at 7,500 rpm for 16oz of fuel and then checked the valve lash and it stayed exactly on .004 inch. All the deposits on the valves and the piston just wiped off.

RVM

I just don't know. I haven't changed a thing. I took it out of the box, put it on the plane and started it. That's all I did. You're much more adept with these and whereever you set it I'm going to leave it, doing exactly what you say to do.

I will go and try it again this afternoon before I go to work.

I've got the tools to do everything but take the bearings out. I may just pull it completely down again and see if something dried out on the valves or valve seats while it was in transit here. That really wouldn't make sense though, because there was plenty of oil and what appeared to be ARO in it.

nismoserspecv

Good Afternoon:

Wow I am very new to this site and I have stumbled upon this form and I have been trying to read all the post for that last week and I am a little overwhelmed by the amount of good information here.

So I was hoping that I would get some great feed back on two Questions.

1. I was given a saito 65 that still has good compression and has cleaned up well. I have taken the crank case back off to see a lot of sludge. I have clean this out with Q tips and brake cleaner. I have also checked the valves and used the little metal tab that came with it to check the clearance and it slides between the valve and the arm with just a small gap. I am going to run it for the first time tomorrow and I am using 20/20 Power Masters fuel. Do I need to check anything else before test running the motor?

2. I also just bought a Saito .91 GK from online and I have ran it on my four star 60. After a ton of tuning it still seems to not want to Idle down past 2200rpms with out quitting. I been using the same 20/20 fuel that I use on YS1.10 which has no issues. Can you help me?

Also will running SeaFoam work? I know it works wonders in a car.

Thanks for your time.

RVM

Welcome.

1. Sounds like your .65 is ready to go. I would squirt some oil (castor, light air tool oil, etc.) into the cylinder, crankcase and down the pushrod tubes. You probably don't have to, but if you just took the engine apart and cleaned it with brake cleaner, then there might not be lube on some of the parts. The first few seconds of running could be a little harsh on the engine, especially if it has quite a few gallons through it.

2. The .91 is an amazingly smooth running 4-stroke and I was able to get mine to idle around 1900-2000 RPM. What kind of prop are you using on yours? If you have a light, smallish diameter prop it may not have enough of a "flywheel" effect to let the engine idle really low. If you are idling at 2200 RPM and it is smooth with a good transition to full throttle, and you don't have any other issues, I wouldn't worry about it. Since you stated that you just got it, I imagine that you may not have enough fuel through it for it to be completely broken in yet. If that is the case, try to tweak the lowspeed needle a bit after a few more tanks of fuel and see what happens.

I was wondering about the SeaFoam as well.

One of our late members put together a document file with a lot of good information about Saitos. It's up to date, as the last version was released in November. I'd be happy to e-mail a copy to you if you like.

nismoserspecv

Yes I did put after run all over in side and down the pushrod tubes and in the valve area and in the crank and down the Cylinder.

I was running a 12x7 on the 91

and 11x9 on the 65

scratchonly

Sounds something like WD40. I don't think it's the same as marine fogging oil, which works just fine. I would hesitate to use it.

RVM

Your .65 should be good to go.

The 12x7 is nowhere near enough load on your engine. If you want a 7" pitch prop try the APC 14x7. I think that's the best overall prop for the engine unless you want to do IMAC or 3d.

freeonthree

My Feedback: (1)

I run a 12x6 on my 65 on a 46 size Decathlon, seems about right for it.

RVM

I just ran my .82. The compression before I started it was better than it has been in awhile. A lot less hissing coming from the intake and exhaust valves when turning it through compression, though it was definitely still there. I turned the lowspeed out a full turn, filled the tank, put a few drops of fuel down the carb and started it. It fired first flip. Idled around 2200-2300 RPM just fine. I let it sit there for a few minutes to warm up and get everything lubed. After about 2 minutes I started to lean the low end just a bit. I got the idle smooth at 2100 or so, which is fine for me. I raised the throttle to let it sit around 2400 RPM for a few more minutes before I started tuning the transition. Within 30 seconds the engine just started rapidly losing RPM and died. I go to restart it and there is not enough compression for it to start again. A stiff breeze could probably turn the engine all the way through compression right now. I'm going to give it a few minutes then go back out there and check it again.

Horizon said since I don't have a sales receipt they most likely won't honor the warranty. The guy said that the engine having been disassembled is actually much less of an issue than the fact I don't have a recepit. blargh. I'm pretty sure I'm going to have to figure this one out myself. If I don't have something accomplished with it by the end of the day Sunday I'll go ahead and send it in anyway I guess.

*sigh*

freeonthree

My Feedback: (1)

After you run it, and the compression goes away, remove the glow plug and put a few drops of oil in ther, replace the plug, and check for compression. If the compression comes back bigtime, your problem is not the valves, but rather in the piston/cylinder/ring area, and at that point I would say pull the cylinder and look at the ring. Maybe the ring is sticking in the groove when it heats up. Maybe the ring is even broken ! I've seen em run with a broken ring before, but not well at all. The idle suffers the worst. I think you may be getting a seal between the piston and cylinder when it's loaded with lots of fuel (rich) then when ya lean it down, you lose what seal you have there. It's worth a look !

RVM

Hobbsy pulled the piston and if there had been a ring problem he would have found it. Also, I don't think that is the case because there is a definite leak around both the intake and exhaust valves. If the ring were broken this would not have been a gradual problem, but rather a sudden one, and I see no reason for the ring not to make a seal.

Regardless, I need to figure out why the valves aren't sealing before I go trying to figure out if there is another reason it isn't running right. Fix the obvious first, then if the problem persists look down other roads.

freeonthree

My Feedback: (1)

Oh, I forgot ya heard the hissing. Yeah, he sure would have noticed a busted ring. lol I need more coffee this morning I guess. lol Yep, you got a valve problem all right. There should be no hissing whatsoever. At this point what I would try first is adjusting the valves loose. I'd set them at about .006 to .008, and let them rattle a little for a while, and see if it keeps running good. Before you adjust each valve, loosen the adjustment a little so there's lots of lash, push down on the rocker arm, and let it snap back up slamming the valve closed good. Then adjust it. When I had one of my engine apart for bearings recently, I made the mistake of squirting some carb cleaner in the exhaust and intake ports, to clean them a little, and I lost all the compression for a bit. All the crap from the port went into the valve seat area, and it lost it all ! The next time I try that stunt, it will be while the valves are not in the head. lol

RVM

What kind of carb cleaner do you use? I may flood the engine with some strong cleaner and see what happens. As long as it won't destroy the seals I think it should be alright.

I'm going to try running it a bit more before I go adjusting the valves. Hobbsy had them set at precisely .004, and I don't want to mess with that right now. There seemed to be a problem with the adjustments before when I had them set. I kept them down to about .0015 or so and it ran fine (though still a bit short on power, which, except for Hobbsy's experience and one or two exceptions that I've seen, it has consistently been a weak engine) and helped make up for the lack of power the engine had. Then, gradually, but very quickly, the engine just started losing compression.


Stupid glow igniter died so I gotta let it charge for a little bit before I can go try the engine again.

Astrodog

Hello All,
I am new to this forum business but I have a question that may have been already answered in a previous reply. I have a Saito 180 on my H9 120 stick lite it will do anything I want and more. recently I bought a new 18X6w prop to replace a badly out of balence master airscrew. It was perfect until I did flew it inverted a ways. when I returned to level flight it died. I curled the pickup tube in the fule tank. I fixed that problem with a little brass tubing. then I noticed another problem. The prop was stripped. At first I thought it was just a loose lock nut but after a few turns i realized it was not going to tighten. I pull out the direction which said to insure there was enough surface are on the thrust washer.

Finally, to my question; does anyone know where I can find some sort of adapter or large surface thrust washer to solve this problem?
Thanks in advance for putting up with my ramblings.
Keep the rudder toward the sky and the wheels toward the ground, well at least when you land.
Astrodog

RVM

What do you mean by "prop was stripped"?

You can get big thrust washers for YS engines here, but I've never seen one for a Saito nor heard of one being needed.