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Old 10-12-2021, 06:19 AM
  #51376  
1200SportsterRider
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A new one on me, a collapsed Saito valve spring. The pictures speak. It was very easy to push open.


Old 10-12-2021, 09:03 AM
  #51377  
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Engine run too lean for too long? Checking the free height of the valve springs I find the exhaust spring on the short side much more frequently than the intake spring. I have never seen one callapsed like that. Yikes!

Last edited by Glowgeek; 10-12-2021 at 09:05 AM.
Old 10-12-2021, 09:05 AM
  #51378  
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When I removed the little keepers, the spring only rose up level with the valve stem.
Old 10-12-2021, 09:22 AM
  #51379  
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If anyone wants a NIB Saito 90T let me know. I'm not asking much for it. The previous owner thought it had been run because it had been mounted. I pulled the plugs, obviously never run.

Last edited by Glowgeek; 10-12-2021 at 09:25 AM.
Old 10-12-2021, 09:45 AM
  #51380  
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Originally Posted by Glowgeek View Post
If anyone wants a NIB Saito 90T let me know. I'm not asking much for it. The previous owner thought it had been run because it had been mounted. I pulled the plugs, obviously never run.
Please PM what you would need for it and I will see if I can afford it.
Old 10-12-2021, 11:14 AM
  #51381  
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Originally Posted by modeltronics View Post
Dave
I use the Klotz Super Techniplate that is 20% castor. I know your feelings on using castor and I am thinking on switching when my supply is gone. I have had exhaust valves get carboned up on small 4C engines. I have also used a Go- Kart oil called Thor with good results but the price has gone up and it is now harder to find. My normal fuel is 18% oil and 3% nitro. This mix works good in all my engines for the type of flying I do. I am always on the look out for a lower cost oil that is good. The Klotz Techniplate is now about $70 and Super Techniplate is about $60 a gallon on Amazon.

Pedro,

The Supertechniplate is running your castor content up to nearly 5%. By cutting it 50/50 with Original Techniplate you can get down to just over 2%, the difference between the two at that point is noticeable.

At the 14% oil mix I use, carbon is no longer close to a concern. While it was light at 5%, carbon is gone at 2% (14% total oil content).

Very happy with the long-term results.
Old 10-12-2021, 04:17 PM
  #51382  
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Gary
That's a great idea. I do have two quarts of standard Techniplate here. My next mix will be with your suggestion. I need to find a good deal on a couple of gallons of Techniplate.
Old 10-13-2021, 05:17 AM
  #51383  
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Dave, Pedro,

A handy little tool, you may want to make a few. Made a few sets of these for the small machine screw sizes.
They got loads of use over the years.

Made from aluminum brass or steel. One setscrew, lightly snugged does the trick.

Drill on-size to match tap diameter.
Old 10-13-2021, 07:42 AM
  #51384  
1200SportsterRider
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Very nice.
Old 10-13-2021, 08:29 AM
  #51385  
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As for the comments earlier on my rich LS, I will pull the barrel and needle out to have a boo, but have the carb swapped and will try and set up the new carb in the next day or two.

Nothing visible on the old one.
Old 10-13-2021, 09:08 AM
  #51386  
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Originally Posted by Glowgeek View Post
If anyone wants a NIB Saito 90T let me know. I'm not asking much for it. The previous owner thought it had been run because it had been mounted. I pulled the plugs, obviously never run.
Would love one, but nothing to put it on, or time to even build something to put it on. The only time I did anything RC related was the trip to Iowa last month, haven't done anything with it since, tool boxes are still in the trailer. After refinancing the house, I got to work on it clearing out the garage, basement and a couple rooms and filled 2 60 yard dumpsters. I am also starting up a farm on my property and acquired a baler, rake and mower. The baler is in good shape, nothing to do to it but grease and oil it, the rake got damaged during the trip home with it, so being repaired at more than I paid for it, but still far less than any other used one around, and the mower I have to pick up 110 miles away on Friday. Thats what has been occupying my time beside my regular job.

Then the house repairs start, so I will need to put up some shelving, store away my RC projects, clear the benches, organize my tools and get to work putting in new plumbing for the bathrooms, and have someone on tap to hire for some tile work.

Maybe in 6 months I can get back to RC, but for now, it is being put on hold. I have WAY too many projects and the days are getting shorter and colder, and I have 3 acres of fence to take down, a hydrant to move, and some gate repairs to do before winter. Then in spring can attack the pastures and get them seeded, fertilized, and weeds killed off for a first cutting. Going to start with hay fields, and once I have a burn pile cleared, plant some sweet corn and vegetables for a farm stand. Will see how that goes.

Until then, just have to give my Saitos a good oiling and put them away for now.
Old 10-14-2021, 02:52 AM
  #51387  
1200SportsterRider
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That valve spring was real easy to compress for about .125" then felt pretty normal. I didn't look at the cam, maybe I should.

Old 10-14-2021, 02:56 AM
  #51388  
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Originally Posted by 1200SportsterRider View Post
That valve spring was real easy to compress for about .125" then felt pretty normal. I didn't look at the cam, maybe I should
Eeeer uuuugh, yeah.
Old 10-14-2021, 03:02 AM
  #51389  
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Based on thee pics and glow plug hole, (or lack of it) assuming this spring is on intake? I have seen most affected on exhaust with the increased heat and contamination.
Old 10-14-2021, 03:56 AM
  #51390  
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Originally Posted by Cougar429 View Post
Based on thee pics and glow plug hole, (or lack of it) assuming this spring is on intake? I have seen most affected on exhaust with the increased heat and contamination.
Same here. On used engines if I find a short spring it's normally on the exhaust side. As a rule, if I find that one spring is shorter than the other by more than .010" I replace them both. Cheap insurance.
Old 10-14-2021, 04:12 AM
  #51391  
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Yep,
The exhaust side is generally the hardest worked side. All the way back to the cam and lifter.

Aside from perhaps an even earlier failure ; A defective spring doesn't care which side it is on.

That spring is just dead, most likely a bad heat treat.

Last edited by Jesse Open; 10-14-2021 at 04:26 AM.
Old 10-14-2021, 04:25 AM
  #51392  
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Here's a thought. I wonder if the previous owner of that 120 overheated the top half of that intake spring during an attempt to remove the rocker pin, or even the keeper C-clip. One of those little butane torches would make quick work of taking the temper out of the top half of a valve spring. Just a few seconds of misdirected flame is all it would take. Always safer to use a heat gun.

And yes Dave, I'm wondering again,

Last edited by Glowgeek; 10-14-2021 at 04:59 AM.
Old 10-14-2021, 06:56 AM
  #51393  
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Originally Posted by Glowgeek View Post
Here's a thought. I wonder if the previous owner of that 120 overheated the top half of that intake spring during an attempt to remove the rocker pin, or even the keeper C-clip. One of those little butane torches would make quick work of taking the temper out of the top half of a valve spring. Just a few seconds of misdirected flame is all it would take. Always safer to use a heat gun.

And yes Dave, I'm wondering again,

Yep,

Very possible.

Any tech worth his salt would never bring a torch flame near that spring.
My favorite heat source in close quarters is a soldering iron or gun.


At the shop when rebuilding cylinder heads, we 100% checked seat pressure at installed height. Any springs not within mfg spec were replaced.


Last edited by Jesse Open; 10-14-2021 at 07:24 AM.
Old 10-14-2021, 08:08 AM
  #51394  
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Ok Gentlemen. To "can't" or not to can't. Please opine, its a Saito 150 on a 89" 15 pound ish golden era of some unknown type. Gonna use the 1/3 chord general starting point for the cg. I don't have the factory spec.

Last edited by Hyjinx; 10-14-2021 at 08:11 AM.
Old 10-14-2021, 10:06 AM
  #51395  
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Here you go Aaron.

https://rcplanes.online/cg_calc.htm

Hope it helps, has worked well around here anyhow.


Grandpa used to have some great advice on
"Wondering". When you don't know something and don't have a clue on how to find out, wondering is about all you can do.

On the plus side, at least you realize that you don't know

Old 10-14-2021, 11:37 AM
  #51396  
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Nice looking airplane!
Old 10-14-2021, 12:36 PM
  #51397  
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Originally Posted by FlyerInOKC View Post
Nice looking airplane!
Thanks Mike. It was an errant pandemic purchase. Good place to park one of my 150's. Make a good winter ski plane.
Old 10-14-2021, 01:10 PM
  #51398  
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Looks like a Monocoupe 90
Old 10-14-2021, 01:35 PM
  #51399  
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Gary, thanks for the CG calc link. I haven't seen that one before.
Old 10-14-2021, 02:42 PM
  #51400  
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Originally Posted by Hyjinx View Post
Thanks Mike. It was an errant pandemic purchase. Good place to park one of my 150's. Make a good winter ski plane.
I have been known to pull the same stunt but I can't blame it on the pandemic.

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