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Like any one really cares. OS has moved the crankcase vent line to the front cam bearings and a line to the intake to improve the oiling of the cam bearings. Thats another great reason to run Saito. No extra moving parts

Well actually, there is more outgoing than incoming on the CC vent. Blowby gasses push oil and other residue out, while the piston moving up pulls in a tiny bit of air. There is actually more coming out than moving back in.
I pulled the back cover off my FG-11 to check on oil and it was nice and wet, with just a little amount of oil still in the crank. This means I got the oil mixture just right.
I also pulled my other 100 apart and replaced the bearings. That motor was not maintained with after run, it was nasty inside.
I pulled the back cover off my FG-11 to check on oil and it was nice and wet, with just a little amount of oil still in the crank. This means I got the oil mixture just right.
I also pulled my other 100 apart and replaced the bearings. That motor was not maintained with after run, it was nasty inside.

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I connect my crankcase vent to a tube strapped to the muffler with the exit pointed toward the exhaust stream like acdii does. They are simple enough to make and the materials are cheap. All you need is a piece of flat brass strip and a piece of brass tubing. I form the slot for the tube around a drill bit the same size as the tube then form the strip around the muffler itself leaving an ear on each end sticking out.. Solder the tube in it's slot, drill a hole in the ears for a small screw to pass thru then install a small nut on the screw to clamp the assembly to the muffler and you're done.

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From my observations the flow is stop and go until about 4,000 rpm and then it is steadily outward. I don't think there is enough "in" to worry about. One of the advantages of the small tubing is that there is not enough time for a full stroke crankcase filling when the engine is running.
Last edited by Hobbsy; 01-03-2017 at 11:36 AM.

I connect my crankcase vent to a tube strapped to the muffler with the exit pointed toward the exhaust stream like acdii does. They are simple enough to make and the materials are cheap. All you need is a piece of flat brass strip and a piece of brass tubing. I form the slot for the tube around a drill bit the same size as the tube then form the strip around the muffler itself leaving an ear on each end sticking out.. Solder the tube in it's slot, drill a hole in the ears for a small screw to pass thru then install a small nut on the screw to clamp the assembly to the muffler and you're done.

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Over the years I've had at least 10 four strokes of which all but 2 were Saitos (40 to 150). From the wealth of information posted here and the guidance of the 'Masters' of this sport on this forum, I've had pretty good luck with the tuning and maintenance of these engines. But recently I was faced with a situation that has me scratching my head.
A club member picked up a Cub with a FA-72 that had been run but was supposedly almost new. No history on how, or if, it had been broken in properly. It wasn't running very reliably (rough low end and a couple of deadsticks) so he brought it around to see if we could tune it up. Checked the gaps and reset them to spec (between .002 to .003). After backing the LSN out to something close to factory spec I started through the regular sequence of peaking the HSN and then very gradually leaning the LSN with small increments with the engine stopped. I was able to back the idle down some and was getting good response on quick acceleration although it was still tending to run ragged on the low end, much more so than I have seen on any of my other engines. After a few repeats of the sequence I happened to notice that the LSN was completely bottomed out.
So what's up here? It doesn't seem like the engine should be running at all at idle, let alone with smoother performance than we had when we started tuning in the first place. Any ideas?
Rick...
A club member picked up a Cub with a FA-72 that had been run but was supposedly almost new. No history on how, or if, it had been broken in properly. It wasn't running very reliably (rough low end and a couple of deadsticks) so he brought it around to see if we could tune it up. Checked the gaps and reset them to spec (between .002 to .003). After backing the LSN out to something close to factory spec I started through the regular sequence of peaking the HSN and then very gradually leaning the LSN with small increments with the engine stopped. I was able to back the idle down some and was getting good response on quick acceleration although it was still tending to run ragged on the low end, much more so than I have seen on any of my other engines. After a few repeats of the sequence I happened to notice that the LSN was completely bottomed out.
So what's up here? It doesn't seem like the engine should be running at all at idle, let alone with smoother performance than we had when we started tuning in the first place. Any ideas?
Rick...
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I have had damaged seats with my TT54 4stroke . It couldnt be leaned out no matter what but that was the H.S. needle . I would say thats your issue but maybe with the low needle . Put some fuel tube on the fuel nipple and with the needles wound in and throttle back see if u can blow air in . If u can theres your prob.

I have had damaged seats with my TT54 4stroke . It couldnt be leaned out no matter what but that was the H.S. needle . I would say thats your issue but maybe with the low needle . Put some fuel tube on the fuel nipple and with the needles wound in and throttle back see if u can blow air in . If u can theres your prob.

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Two items on this page will fix you up, the idle needle, (actually a sleeve that slides in and out over the spray bar), and the spray bar itself.
http://www.horizonhobby.com/72-aac-w...3A-rr-saie072b
For some reason the whole link does not paste, just click on parts and accessories.
http://www.horizonhobby.com/72-aac-w...3A-rr-saie072b
For some reason the whole link does not paste, just click on parts and accessories.
Last edited by Hobbsy; 01-04-2017 at 05:44 AM.

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I'll have to pull the carb and have a look at the tube. It doesn't seem to be screwed that far in compared to the others I have so perhaps that's the problem. Before I pull it down I'll try the blowing in the fuel tube trick mentioned by 'The Pope'.
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Mine was left at its original settings when mine went kaput too . I never wound mine all the way in except maybe when brand new . I imagine vibration could be at fault .

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Yep, that's the new 585 cubic inch Turbo Diesel one.
Good morning Pete, I have a new CH Ignition system coming for the Saito 1.50, the old 1997 system Hall effect sensor was getting intermittent.
Good morning Pete, I have a new CH Ignition system coming for the Saito 1.50, the old 1997 system Hall effect sensor was getting intermittent.

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This is an excerpt from LASER engine instructions, I like it, it's honest and spot on.
2. What are the needle settings for the carburettor?
There are no ‘correct’ settings for the carburettor. Each engine will have to be tuned to suit the specific installation. Other factors that affect tuning are propellers, glow plugs, fuel and atmospheric conditions. As a base setting set main needles to 2.5 turns and slow run needles to 6 turns on large single engines (120, 150, 155, 180) and 7 turns on small engines.
2. What are the needle settings for the carburettor?
There are no ‘correct’ settings for the carburettor. Each engine will have to be tuned to suit the specific installation. Other factors that affect tuning are propellers, glow plugs, fuel and atmospheric conditions. As a base setting set main needles to 2.5 turns and slow run needles to 6 turns on large single engines (120, 150, 155, 180) and 7 turns on small engines.

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The suction will be optimized by the way the pipe is cut. I'm sure it can be found easily with a search. I've seen a nicer look on a model that had copper tubing flush with the leading edge of the landing gear to pull the oil down and away from the fuselage bottom.

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Hey quit stalking us or we'll all gang up and report you
how are you mate?
Dave hope that ch ignition calms the 150 down a bit,would be good to see prop figures if you do them.
I've been spraypainting motorcycles for years and something unusual popped up the other day.It was ridden in by a big fully tatted (we call them tramp stamps here) guy and his attitude.It had a 350 chevy ls3 v8 in it and i reckon if you lift the seat you'll find an a4 sized hospital four star food menu guide..

Dave hope that ch ignition calms the 150 down a bit,would be good to see prop figures if you do them.
I've been spraypainting motorcycles for years and something unusual popped up the other day.It was ridden in by a big fully tatted (we call them tramp stamps here) guy and his attitude.It had a 350 chevy ls3 v8 in it and i reckon if you lift the seat you'll find an a4 sized hospital four star food menu guide..
Last edited by Hobbsy; 01-07-2017 at 03:37 AM.

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Hey Pete, I'm good, in my book there is no such thing as too much compression, my old .80 is 15.5 to 1 and the 1.50 is 11.24 to 1. My neighbor has a bike with a 350 Chevy in it, it only has 280,000 miles on it. It rarely sits still. We are supposed to get in the neighborhood of 9 inches of snow today, got about an inch already. A good day to burn wood and read a good book.