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Old Aug 30, 2009, 09:58 PM
The reviewer
XJet's Avatar
Tokoroa
Joined Mar 2004
3,827 Posts
Quote:
Originally Posted by kayakcarl
Would someone give me advice on how I might stop the muffler and carburator from vibrating loose on my new Saito 1.50 4 stroke? I am breaking it in on a test stand and this is the 2nd time the muffler and carburator have loosened up. Will Blue Threadlocker(Permatex) work with the heat of the engine?
Run the engine until it's hot.

Stop the engine.

Re-tighten the exhaust.

Works for me (and everyone else that's tried it).

The secret is to retighten when hot.

The aluminum cylinder expands more rapidly than the steel header tube so if you tighten when cold it *will* get lose when the cylinder expands and makes the header tube become a loose fit.
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Old Aug 30, 2009, 10:33 PM
Fly'em like you Stole'em
MikeMcChiken's Avatar
The Gehto,Ca.
Joined Jun 2008
1,117 Posts
Yep , tighten when it is hot . Works for me too . I have never had a carb come loose but my rear housing caps are plastic that the carb screws go into .

Hey Itober , Is there any truth to a smaller saito running irratic if there is an air leak in the valve cover gaskets ? Heard it is very true for a YS but saitos are only slightly affected .
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Old Aug 30, 2009, 10:36 PM
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Joined Sep 2002
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Oh God , please dont make me haft to get those leak proof !
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Old Aug 30, 2009, 10:42 PM
Fly'em like you Stole'em
MikeMcChiken's Avatar
The Gehto,Ca.
Joined Jun 2008
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Quote:
Originally Posted by flyinghigh
Oh God , please dont make me haft to get those leak proof !
LOL
I wasn't going to stress over it . I was adjusting my valves at the field today and a friend there was giving me advice . You know , Field BS'n . He always has great running 4-bangers . Probly cause his job is working on the real ones .
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Old Aug 31, 2009, 02:23 AM
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Santa Cruz, CA
Joined May 2007
86 Posts
Some .45S Advice

If you don't mind me hijacking this thread, I would like to ask for some advice on the above engine. I was wondering what you (anyone) would recommend for a propeller (it's in a sport plane with a 12x7), glow plug (currently an OS F), and a decent starting point (preferably the factory setting) for the LSN.

Currently the engine will not pass the nose up test on the ground (or in the air for that matter) and it will not idle below 4K or so.

I plan on checking the valve clearances as soon as I get some feeler gauges. I know it will get more power, but will it affect reliability and such?
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Old Aug 31, 2009, 02:32 AM
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Sydney
Joined Apr 2009
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[QUOTE=Dad_Roman]Running hot = not enough fuel.

Yes it does come to a knife edge. the engine was originally to be fitted with a close fitting pressure cowl, but this has not been done yet. The prototype flew easily on a Methanol Moki 23cc.

Thanks for the advice. We have not had the reported problems yet, so hopefully the source of the problem reported to us was due to one of the issues mentioned.

all the best.

John
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Old Aug 31, 2009, 09:42 AM
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I TOBOR's Avatar
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Mike, while it is true of the YS it is not true of the Saito, the YS uses the rocker box as part of the intake plenum to store part of the intake charge. On the YS there are four holes along side the intake valve stem that let part of the supercharged intake charge flow up into the rocker box, and then of course it flows into the cylinder when the intake valve opens. Saito have no such holes, you could run the Saito without the rocker cover gaskets and other than an oily head have no issues at all. In fact you could run the Saitos without the cover.

I had 4 YS engines at one time but got rid of them all, they were just too much hassle to keep running. When thy were running right they were schweet but when they decided to be contrary, which was quite often, they were hateful.
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Old Aug 31, 2009, 09:06 PM
Fly'em like you Stole'em
MikeMcChiken's Avatar
The Gehto,Ca.
Joined Jun 2008
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Quote:
Originally Posted by RocketMan09
If you don't mind me hijacking this thread, I would like to ask for some advice on the above engine. I was wondering what you (anyone) would recommend for a propeller (it's in a sport plane with a 12x7), glow plug (currently an OS F), and a decent starting point (preferably the factory setting) for the LSN.

Currently the engine will not pass the nose up test on the ground (or in the air for that matter) and it will not idle below 4K or so.

I plan on checking the valve clearances as soon as I get some feeler gauges. I know it will get more power, but will it affect reliability and such?
I just redid the valves on mine with help of friends . I put some new seals in it and reset to factory settings for kicks and giggles . It wouldn't even run with the LE even with the throttle arm . It would run a few seconds and slober oil all over itself like a newborn baby . Nobody I know does a nose up test with a 4-banger . Don't know why . Seems unnecessary .

I would prop down a little . The biggest prop the book talks about on a .50 is 12x6 .

Itober probly knows that motor . I just have newer ones so I am not sure what type of carb is on there . If your lost thought , factory settings is always a good start point.

Hey are you the rocketman from ebay with all the older kits ???
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Old Aug 31, 2009, 10:32 PM
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Joined May 2009
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I just bought 2 Saito 72 .. for a twin project .. I ahve heard great things about this engine and seen and hear a few .. 1 question I do have is the age old ... how does it do on drawing fuel over a distance of say 8" ...and has anyone run without muffler pressure with no draw problems ?

Thanks ... love the idea of the Saito forum

have 220 & 180
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Old Sep 01, 2009, 01:50 AM
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United States, GA, Ringgold
Joined Oct 2005
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Quote:
Originally Posted by ceeg
I just bought 2 Saito 72 .. for a twin project .. I ahve heard great things about this engine and seen and hear a few .. 1 question I do have is the age old ... how does it do on drawing fuel over a distance of say 8" ...and has anyone run without muffler pressure with no draw problems ?

Thanks ... love the idea of the Saito forum

have 220 & 180

An 8" distance to draw fuel is asking a lot of a suction fed engine. Add to that, or subtract, actually, the fact that you are thinking of running the engines without muffler pressure and you end up with a high probability of unsteady engine runs and perhaps deadsticks, resulting from poor fuel feed.

Enter the Perry VP-20 (oscillating) fuel pumps. A pair of these (one for each engine) could turn your project into a winner with no extra setup adjustments to make.


Ed Cregger
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Old Sep 01, 2009, 07:54 AM
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I TOBOR's Avatar
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Bob. a 12x7 is more suited to the Saito .62, a 12x5 or 11x6 would be more suited to the .45. The .45s is a strong engine with the right prop.

Ceeg, your setup is a perfect place for a couple of Cline regulators, you'll have complete piece of mind from full to empty. Using the Clines you save a lot of fuel because you no longer need to set the engine 300 rpm rich to prevent leaning near the end of the tank.

The Perrys will work if you get two that are adjusted properly, they are real pain to adjust yourself. At best you'll still a very rich midrange using them.
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Old Sep 01, 2009, 08:35 PM
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USA, TX, Teague
Joined Jul 2007
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Quote:
Originally Posted by OZPAF
Yes it does come to a knife edge. the engine was originally to be fitted with a close fitting pressure cowl, but this has not been done yet. The prototype flew easily on a Methanol Moki 23cc.

Thanks for the advice. We have not had the reported problems yet, so hopefully the source of the problem reported to us was due to one of the issues mentioned.

all the best.

John

I dont have one of these beasts but I have run many many industrial 2 strokers in various applications (including a world record holding 1/4 scale sprint car **practically no cooling***)

Some engines are very finicky about their mix ratio and even brand of oil.

Let us know if you hit any more problems!
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Old Sep 02, 2009, 05:25 AM
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Santa Cruz, CA
Joined May 2007
86 Posts
Quote:
Originally Posted by MikeMcChiken
Hey are you the rocketman from ebay with all the older kits ???
Nope, sorry. I do fly older stuff, but no.

I flew a few days ago, turned in the LS about 1/8 turn and it's champion! I guess I could try a smaller prop too. Is there any downside to using a slightly bigger than recommended prop?
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Old Sep 07, 2009, 08:58 PM
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United States, CA, El Mirage
Joined May 2007
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just got my first ever Saito , need some advise please. I know that reading through this entire thread to find the answer could take all day so I'm going to ask.

what does the plumbing diagram look like ? my new 115FA has a muffler tap and a crankcase tap , which goes where ? and do I need a one-way valve ?
I have owned dozens of glow engines but never a 4st so I could use some advise.
this new eng will be installed in a fusionX .
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Old Sep 07, 2009, 09:18 PM
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I TOBOR's Avatar
Joined Feb 2007
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The crankcase vent just vents to atmosphere below the model, the shorter the better. No check valve is needed unless you're using a regulator like a Cline or IronBay.
Do you have a test stand, that is by far the best way to break it in. Connect the muffler tap to the tnak vent just like a two stroke. If you see black stuff in the expelled oil from from the vent do not worry it is only black grease from the bearings, rod and cam.
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