Topic: Saito FG 36 Feedback

Can any owners of this engine share their experience to date.

I bought one myself (to put into a stearman) a few months ago but have yet to run it.
However, I have read numerous 'threads' on this engine (as you do) and have become a little alarmed at some of the negative responses.
Like many, I have owned and enjoyed some of the larger saito glows in the past but have opted for the cheaper  running (and paint friendly) Petrol jobbie.

I do not expect mind blowing power, but would hope for faultless reliability and the ability to swing a decent size prop.

Any honest feedback before I commit to a model that I have invested a lot of time with would be very much appreciated.

Thanks.

Hi, I have one of these engines and until recently I was very impressed with it. It was powerful, clean and had a great sound about it. I have just changed the crankshaft and can't seem to get it running as good as before. Hopefully a little bit more tinkering and I'll get it running just right. Here's my 36 in my 74" wing-span EF Yak 54.

Sent from iPhone

Simonslim,
That's reassuring to hear.

I've read lots on overheating and 'cutting out in the air etc whilst running fine on the ground' ...there have also been complaints of poor(?) power on some forums.

Questions.
Why are you having to replace the crankshaft and what sort of size props have you tried?
 
For the record I am hoping to haul @20lb's of biplane with mine (albeit in a scalelike fashion and I am neither expecting or requiring sportlike performance)

By the way I couldn't see any upload on your post.

Thankyou.

Send 'SteveR' an PM....he 'had' 2 of these in a twin until earlier this year......recently replace by ZG38's........that may give you an idea as to why?

Phil

I replaced the crankshaft as this engine had been fitted to a helicopter in a previous life, and had it's crank shortened to fit the clutch-bell and restricted the fitting of other types of props and spinners. The Yak would prop hang, just, but was totally trouble free and a great plane to fly and it never cut out once or gave any cause for concern.  It has since been fitted to a Precedent T240 which takes off on 3/4 throttle and chugs around on half throttle. On a 20lb biplane I think it might struggle a bit and might be on the edge of fun, not-fun.

here is a video of a club mates FG-36 in a Hanger nine 150 size P-47, they weigh around 17-18 pounds,
The engine is now 2 years old and no problems with it as far as I know.


Simon

P47 Thunderbolt

Hi Simon

Its worth checking the valve timing on saitos they are a bu@@ar to reassemble accurately .I have done work on several different glow saitos and found the valve timing to be standard (I make a timing disk before dis assembly). I can't comment about the petrol though. The glows do run with the timing a tooth out but not very well. You can make a tool to hold the cam shaft gear still while assembling the valve gear

Alan

Hi Alan, is it possible for you to send a picture of this tool, as I have been hoping when replacing the timing gear housing that it has not moved a tooth.

I dont have a pic, I use a timing disk , RGN on here has though. Im sure he will respond to a PM otherwise search the forum he did post a pic a few months ago

Alan

I dont have a pic, I use a timing disk , RGN on here has though. Im sure he will respond to a PM otherwise search the forum he did post a pic a few months ago

Alan

Can any owners of this engine share their experience to date.

I bought one myself (to put into a stearman) a few months ago but have yet to run it.
However, I have read numerous 'threads' on this engine (as you do) and have become a little alarmed at some of the negative responses.
Like many, I have owned and enjoyed some of the larger saito glows in the past but have opted for the cheaper  running (and paint friendly) Petrol jobbie.

I do not expect mind blowing power, but would hope for faultless reliability and the ability to swing a decent size prop.

Any honest feedback before I commit to a model that I have invested a lot of time with would be very much appreciated.

Thanks.

I had one, was very easy to start, very economical but not that powerful. Had mine in an EF yak 54 and was not enough for 3D.

If you do get one then make sure the carb is fed with fresh cold air, mine suffered from burping. It throttled fine to full throttle on ground but in air and half way through take off and  in rolls, off would cough / burp.  Very annoying considering the cost.

Do a goodle search on FG36 Burping and read the reasons why. Ended up selling my one and got a faultless DL50 (sounded Carp compared to the saito though)

I’ve read and studied all the threads too.

Which operating instruction manual have you got?  The original Saito one is rather poor, and the one to use is version 2009 published by Horizon Hobby USA which can be downloaded from the horizonhobby.com website:   http://www.horizonhobby.com/ProdInfo/Files/17326_SAI_FG14_FG20_FG30_FG36_Instruction_Manual.pdf

There might even be a later version.  A clubmate has just taken delivery of a FG-20 which has a manual incorporating some of the suggestions below.

After reading the threads, I bought a secondhand unused and NIB FG-36 from a chap called Tony (Thonnor on the RCU threads) who won’t run anything but Saito petrols, and who currently flies two 20cc in a ASM Tigercat twin, two 30cc, and a 36cc in a H-9 large P-51 which weighs about 17lb.  Tony demo’d the T’cat and P-51 for me at Merryfield when I went to collect my FG-36 from him, and both models flew exactly as they should for WW2 fighters.  And they sounded good too.  As I was just moving back to i/c after 13 years of solely electric flight (which had followed 40 years of i/c flying!) the way these engines performed and sounded was most encouraging.

Tony gave me the following advice for the care and feeding of Saito petrols:

Before running the engine, put plenty of oil in each rocker box, and replenish every so often until fully run-in.  Otherwise the valves can stick before they’re run-in.  I remember that this advice was given by Laser for their engines when I operated them back in the  1990’s, so that didn’t seem an unusual or excessive rquirement to me.

For the oil, the Evolution Oil as distributed by Horizon Hobby UK is the stuff to use as it runs cleaner with less carbon build-up than other oils might do.  Code no EVOX1001Q synthetic 2-cycle oil.

http://www.horizonhobby.co.uk/aeroonline/e9evolution/e9acc/e9afteroil/e9afterrunoil.html

 It’s about £11 a US quart and available from any Horizon dealer (ie any shop that sells  Hangar-9, Spektrum, E-flite etc) – I get mine by post from Kessock Models in Weymouth as we don’t have any model shops within 60 miles of where I live in North Devon.  Any high-quality synthetic 2-stroke might do as well, but none are any cheaper and the engine uses so little fuel that I can’t see much point in experimenting.

The old manual recommends 30:1 petrol:oil after running-in on 20:1, but don’t make the change, and carry on using 20:1 ratio for all flying as the lubrication is needed.  Again, the engine is so economical the oil bill is affordable.

Use only a 4-cell nicad, or 5v regulated supply as a 5-cell risks burning out the ignition.  Tony did burn out an ignition module on a 5-cell nimh, so now uses a cheap 5V regulator with a 2-cell lipo.

Tony has ignition lights on his models.  He uses a blue flashing LED which you can buy from Maplin.  Connect it across the ignition battery input, and it’ll remind you when it’s switched on.   http://www.maplin.co.uk/Module.aspx?ModuleNo=33347

The carb is dead easy to prime.  You fully close the throttle barrel, and then pull the barrel out sideways and flip the prop over a few times to suck-in.  The way Tony does this is to attach a small tie-wrap to the throttle arm and have the end poking out of the cowl.  Pull on the tie-wrap to pull the barrel out for priming

Run the engine in for an hour on the bench.  To do this, Leave the low end needle on default but richen the top end so it will only run 4000rpm max for a couple of tanks. Then over the next 2 or 3 tanks lean the top end out until it holds full throttle without fading or missing.

Once you've achieved this you can alter the low end needle (normally by leaning) to achieve good idle, mid-range and transition.

The transition from low to high throttle should be progressive and, you should avoid slamming the throttle open - This tends to cause the motor to suck in too much fuel too quickly and can choke the engine a bit causing it to stutter.  (It’s probably worth slowing the throttle channel speed somewhat)
 
They need to be mounted firmly and not on rubber mounts. If the engine wobbles too much it upsets the carburetion - it's a pumped and regulated diaphragm carb and too much wobbling will upset the regulator. Make sure your test mount is nice and stiff.

Use the supplied alloy mount in the model, as it acts as a heat-sink.

As commented earlier, make sure that the carb gets a good supply of cooling air blowing over it, using ducting if necessary.  Attached pics show what Tony did to duct air to the carb in his P-51, and another shows my running-in mount on an old picnic table.

I’m building a 27.5% (about 6ft span) Bucker Jungmeister for mine, though many distractions are slowing progress.  I have finished the plans at last, and cutting-out the parts will start next week.  I’m not into 3-D aerobatics though (I’m too old and slow for that) but I’m looking forward to lots of prototypical ones.

I have run my FG-36 in as detailed above, and another clubmate with a FG-30 followed the same advice.  Both our engines are trouble-free, though they do need a minute or so to warm up on the ground before flying.

Gordon

All, Gordon,
Thank you very much for you help.

It is encouraging to see that some people have success, although somewhat a pity that Saito has produced something not particularly user friendly (perhaps) in this instance.
As I stated in my earlier post I have had nothing but great success with glow versions. However I have found them very thirsty in the larger sizes (hence my change to Petrol).

Gordon.
Any idea what size props this engine can handle comfortably?

Fingers crossed.

Happy Flying.
AM6.

Thanks for all the user info regarding the Saito petrols Gordon.

I'm seriously contemplating the purchase of either the FG20 or FG30, and am still evaluating which one would be better suited to the models I'd use it in. I did read a few comments on a US forum earlier this year regarding what appeared to be suspect quality ignition systems, but hopefully Saito have resolved any issues by now.

@ am6:  Saito recommend using a smaller prop for running-in, and I’m using the APC 18x8 wide blade which I used for running-in and will continue with that for another couple of hours in the plane until I’m certain it’s fully loosened up.  Then I expect to increase prop size to a 20x8, which is what I’ve seen recommended by some FG-36 users.  At around £52 from Probuild I don’t fancy the price of the Mejzlik, and a 3W beech for 13 quid, also from Probuild, is what I’ll get next.  The APC 20x8 is about £28 at Inwoods.

One neat aspect of the engine is the way that the exhaust pipe can be positioned so that the muffler is just about dead centre behind the cylinder head, which will be very convenient when mounting it inverted in the Jungmeister’s radial cowling.


@ Brian:  I’ve read the comments regarding ignition system problems too.  However, when I was flying high power (4kW) EDF, there were always guys around on the forums who would rubbish the Stumax fan and Schulze esc I was using, despite the power system’s reliability and the model’s genuine jet flight performance.  Conversely, there were loads who said how wonderful various lipo makes were, and these puffed and suffered cell failure when I tried them.  It was my experiences with the expense and short life of lipos for high power electrics that drove me over to a MW44 turbine for jets, and the Saito for props as being both cheaper and less hassle!

It’s funny, but I’ve been flying a scratch-built 1/5th scale Tiger Moth on around 800W electric for about 9 years.  It began life with a geared inrunner which produced annoying gear noise.  So 6 years ago I fitted an Axi outrunner, which since then has generated an annoying whine which I presume is the esc frequency.  Now that Saito have produced the FG-14, I can see my Tiggie getting its third engine transplant and a decent sound at last!  And before anyone suggests it, there’s not enough room in the slim Tiggie fuz to house the speaker for an electronic sound system, even if the plane could stand the excessive weight increase.  The nice thing about the petrol Saito is that the cellulose exterior finish wouldn’t need any fuel proofing.

Gordon

I had two FG36's and an FG20 and now I dont, for the money they are not as good as they should be.

Kniverflyer,
I am assuming that the fact that you now have neither of the 36's (your post) was because they didn't suit your needs/application (or similar?).

Could you elaborate a little?
I need 100% reliability....might I find this not be the case?

I am soon approaching the stage in the finishing where an engine swop would be very difficult..and would therefore appreciate as much 'heads up' as is possible.

Thanks,
Am6.

Had our Saito FG36 now for well over two years.

Not had any problems, easy to start. Runs on a 20x8 prop.

We use GOOD 2 STROKE OIL eg Silkolene which is around £8 a litre but believe in using good quality oil.

Only maintenance done on it slight carb adjustment according to weather, summer, winter etc and the tappets twice in two years.

Its cheap to run, and been pleased with it since we bought it 

Oh it is in a Hangar 9 P47........

150 size

Never had any problems with lack of power or anything......

Also forgot to mention about running in.......

It took around 2 1/2-3 Gallons of fuel before it settled down and was run in.

Saito FG-36 first run

Short video of the saito on its first run......

P47 has changed a bit since then 

All,
I have finally got around to using my Saito FG 36 and thought that I would post my findings to perhaps help others who have had similar worries about what this engine will (or wont) do...
Basically I had read far too many on line reports and become very concerned with the amount of negative
reviews and the amount of problems that others had seemingly encountered.

I have used a well flown 50cc size airframe (Yak 54) as a donor to gently get some 'gentle' flying time in.
(86'' wing @ 18lb - using 18 x 8 Prop for break in as per Saito).

Firstly I pretty much followed the Saito instructions for the first runs and spent a couple of hours with ground running to start the break in process.

I then progressed to flying and thus far have about one and a half hours 'air time' on the engine.

What ''I'' have found so far....

The engine has started by hand 'from the off', using the Saito procedure, either first or second flick every time.

The performance seems at least on par if not better than the 180 glow version (had one for many years).

The engine has been particularly messy, although the amount of 'black gunk' is getting less as the break in progresses.

The performance in the above airframe at this point in the proceedings (very earl;y days yet) is sufficient to fly very safely, requiring a little more than half throttle to maintain level cruising circuits. 

At full throttle it will haul the airframe through 'small Ioops' but as yet I have tried nothing too adventurous so as not to overload the engine whilst still tight.

One thing maybe worth noting is that it was obvious on the first flight that the low end was very rich, so I adjusted the the low end by 1/16 of a turn with the intention of gradually 'sneaking up' to a better setting.
However, this '1/16th' done the trick completely - so tiny setting adjustments are the order of the day on the carb it would seem.

To sum up 'my findings'.

My Initial concerns were unfounded as the engine has run faultlessly.

Reliability 'so far' 100%

The engine uses 'absolutely tiny amounts' of fuel...although I had read this elsewhere, it never ceases to amaze when I refill following flights.

The engine is very messy....but becoming cleaner.


I hope that this helps others who may be pondering the fg series, certainly if you want a very quiet petrol engine, that sips fuel, this could well be worth looking at.

Point of note  - slightly related, a fellow club member is running an FG.20 and has had no problems either. (I have seen it fly plenty of times- and it goes very nicely indeed).

Happy Landings.
AM6.



 

Here are a couple of ideas for dealing with oil splash.

The first pic shows how I'm collecting crankcase breather oil.  The FG-36 is mounted inverted.  Works well as there's no dark oil residue on the airframe.



I found the following pics on a thread somewhere, possibly RCU, and I might just try it out as my FG-36 does leak oil from the exhaust valve rocker cover.  The theory is that the exhaust valve chamber collects oil blown by the valve stem, whereas the inlet valve chamber oil is scavenged down the valve stem by the induction stroke.  So the intake valve apparently collects the exhaust valve blow-by.









Gordon

Gordon,
I have seen sight of these mods elsewhere, but I was not keen to recycle oil that had already been used once in the engine, particularly that within the combustion process (the thick oil deposits that collect, and then leak out, via the exhaust rocker (and smother everything in it's slipstream)).

What I ended up doing as a 'semi fix' was to fit a nipple into the exhaust rocker cover and by way of a short piece of silicon tubing 'tee into' the crankcase breather that I have extended to a convenient point below the fuselage.

Used oil still needs wiping away of course, but now tends to be a lot more localised to the bottom of the airframe only and keeps the engine bay a lot cleaner.

Happy Landings
AM6.

All,
After 10hrs of 'flying time running' I thought appropriate to update earlier findings..
 
I had originally been running an 18 x 8 Xoar (7500rpm).

By and large it has performed well, although I have noticed the burps etc when rolling, but the engine has never stopped and I have still been pleased overall.

However, I recently started experimenting with different size props in an effort to see what performance I could expect to get out of the engine..

Before I started I thought best to check plug and tappets etc. to ensure optimum conditions.
When I cleaned and checked the plug I found that I had originally 'wrongly' set the gap to 20 thou (per CM6 instructions) as opposed to the saito manual (which states .6-.7mm)  - so reset to just under 0.7mm.

With the plug gap at this 'new setting' the engine performed very poorly, misfiring badly at anything over @ 1/3rd throttle.
I tried various carb settings but could make no appreciable improvement...eventually 'remembering' that the only thing that I had changed from the earlier flights was the plug gap(?)....so back at .5mm on the plug and try again...whereupon the engine was back to previous 'good running'.

However, when going up to a 19 x 8 (menz wood 6700rpm) the engine ran well up to about 85% of throttle travel whereby it would misfire slightly refusing to clean up.

I then tried a 20 x 6  ( JFX wood 5800rpm) where the same symptoms occur ed?

I am starting to wonder if I 'may' have an ignition problem that is coming to light?

I must stress that the engine has had many acceptable flights previously....

Any thoughts appreciated?

Thanks,
AM6.

It sounds as if your ignition battery is giving up the ghost and can't handle the ignition system current bursts any more.  Or maybe there's a high resistance connection or switch contact in the ignition battery supply.

A couple of Saito petrol users I know had similar problems when using 4-cell eneloops or instants, I can't remember which, and cured the misfiring by changing to nicad/nimh.

Gordon

Gordon,

That's a good train of thought that I had read elsewhere at some point.

In preparation for my next outing I have fitted a 'sub c' ignition pack feeling that perhaps the colder weather (and uncowled installation) may be making my original pack (eneloop AA) struggle.

I will provide an update following following my trials to rule out ignition.

Fingers crossed...

Just out of interest - what prop/rpm combos have you found yours capable of.

I was a little dis heartend comparing mine to factory - but have not tried carbon and wondered if worthwhile to gain that bit extra?

AM6.

Mine does 7800 on APC wide blade 18x8 and Menz wood 18x8.  I bought a 20x8 Mejzlik for it but that turned only 6800, and possibly less as I can't really remember, which would have been OK for a WW1 floater I guess, but I didn't feel it would have the required oomph for my Jungmeister, which goes just right on the 18x8s.  I haven't tried any other props.  The only rpm figure quoted in the user manual for the FG-36 is 8300 on an 18x6 APC wide blade, compared with which I feel that 7800 on an 18x8 is rather less than it should be if Saito are to be believed.

I'll save the 50 quid Mejzlik prop for a bigger engine if I ever get one, and stick with the APC for the Saito.

Gordon

Update.

I tried various things to get around this 'misfiring'  problem in my earlier post - including fitting a sub c ignition pack and checking all connections etc.etc. but could make no real improvement.

At a list ditch attempt I replaced the Saito ignition with a RCXCEL unit and ''Bingo''.

Engine now runs with .7mm plug gap.
Menz 19 x 8.
idle rpm - 1400 Very reliable
Max rpm - 6800 Smooth and steady.

Gordon,
I have found that this unit performs very well on the Menz wood 19 x 8 and perhaps worth a try for better overall performance?
Certainly livened up the 18lb 'Donor airframe' that it is currently being tested in.

Happy Landings,
AM6..

AM

How old is your FG36? I ask this because I'd heard there were a few issues with some early ignition units supplied with the FG36. It's good you've finally got it sorted though.

I'm thinking about the smaller 20cc one. Maybe I'll take the plunge later this year.

Brian,

My engine is not one of the early models....@ 15 months old.
 ''Perhaps'' there is either an underlying 'ongoing' problem or I was just unlucky?

Worth also noting that this problem did not really come to light until I started loading the engine with larger props - so it may never be noticed in lighter use (Unless of course you 'normally fly' at very high throttle settings?).

AM6.

It shouldn't do at any throttle setting AM. I'd send the ignition unit back, asking for it to be checked and tested......

Update.At a list ditch attempt I replaced the Saito ignition with a RCXCEL unit and ''Bingo''.

Wich RCXCEL unit did you buy? Any adjustments or just to swap the unit? I do have top setting trouble. idle to mid is good but seems like I am not able to tune the top. Engine is struggling, but it works ok if I do the transition very slowly and do not have the WOT but keeps it to 90% open....

For the cost of this engine there should be no issues. There are and that's why many folks have sold them. Really poor of Saito to release such a lemon.

Affas,
The replacement ignition that I have used is the standard RCXCEL single CM6 Plug type.

The only work involved will be to re-time at @ 28 BTDC.
To enable this to work I ended up using the larger of the two supplied sensor clamps, utilising only one of the arms of the brackets to get it to align correctly.
I also drilled another 3mm hole to clamp it securely (using two fixing points in this one arm...see pic).

Seeing your comment re high end misfire made me smile...
At one point on a very cold day I ended up utilising only 80% throttle travel via ATV on my radio
to get a couple of flights in with the larger props...so as to stop the misfiring.

Happy Landings.
AM6.

FWIW....

I had 2 Saito FG 36's....both were initially run for an hour on the ground on a test bench....using all the above mentioned tricks..(right oil, filling rocker covers with oil, ratios etc) and the engines ran great.

Fitted each engine in turn to a 1/3rd scale Chiltern DW1...and on the whole they ran well. Over about 3 hours of flying I only had a engine quit once and that was mostly my fault as I had been playing with the mixture...flying in bad weather when the hail started...a hurried approach went wrong and opened the throttle too quickly.....end result was a deadstick landing in the adjacent field and a cold forehead while retrieving the model in the hail storm!

I did have the occasional issue of the engine coughing during the initial application of power on the takeoff run..but this never caused too much alarm ( I always consider myself to be fairly careful with opening throttles...never to slam then one way or another (cause I know the end result!). I also had issues with the engines 'burping' or coughing during the inverted portion of a roll. Again, the engines never stopped but it was and annoying issue more than anything else. I tried all sorts...but could never totally get rid of the issue. I did end up feeling confident enough with the engines to fit them to my new twin (the Libellula) for the test flights....

99% of the time the engines ran fine in the Libellula....still the occasional misfire or cough during the takeoff roll....this now causing a slight swing into the 'coughing' engine and I aborted a few takeoffs....just in case.

I also had a few misfires in the air...usually after about 5 mins of flying at a constant throttle setting. Nothing serious, but it made my heart jump everytime and usually ended in me curtailing the flight for a stiff coffee!

One day....I rolled up at the field. (warm day....25-27 degrees) and one engine just didn't want to run. It would start...but wouldn't go much above idle without misfiring, popping, gurgling and spitting...and then stopping. Cowl off...it ran better, not perfect, but better. Cowl on again...nothing.

Maybe there was some issue with the airflow within my cowl. That may well be my fault...maybe an ignition issue or whatever....but I had about had enough so the two Saitos got the boot and two Zenoah 38's installed. The Zenoah 38 doesn't quite have the power of the FG36...no surprise really as Zenoahs aren't known to be powerhouses...but they are ultra reliable and do the same thing day-in, day-out.

I wish I had had more success with the Saitos....some people seem to really rate them. They are certainly built nicely and have lots of power. They were a breeze to start and had a lovely and slow tickover........ in a single engined model I might just have another.........perhaps.

I hope this helps.

There should not be issues with an engine that costs as much as this. Just unacceptable IMO. 

Just a thought Saito glow engines have a high compression ratio ,maybe they haven't reduced this enough for a petrol conversion .The petrols do look like my glow 180's so I suppose the petrols are conversions .High compression ratios lead to pre ignition in petrol engines could this be the problem? It could be worth putting an extra head shim in to see if this helps.
Alan

Alan that isn't possible. Saito engines have no separate cylinder head. The head and cylinder are cast as a single unit.

Yes you are quite right Brian a bit early this morning!! .Putting a shim between the barrel and crankcase would have the same effect though

Alan

Hi,

Is it possible to use unregulated 2S LiFE with a nominal voltage of 6,6V when charged?

Thanks
Alf Hansen