john melia 1 Posted April 13, 2017 Share Posted April 13, 2017 i've just bought a saito 125a fs ,and installed it in a seagull glasair , the tank came with the model , and has a built in mount in the fusalage where i have duly installed it the engine is mounted horizontal as per the manual , but the fuel supply from the tank is approx 2 1/2 inches below the carb i have not got any experience of fourstroke glows , only two strokes glows , and petrol engines would this cause a problem , if so is there any type of pump i could use , and where could i get one Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted April 13, 2017 Share Posted April 13, 2017 first of all john the saito 125 is a very nice engine for general information about saito this website is very good. ideally the centre line of the tank should be level with the carb or a little lower. but I would just try it as see if it runs ok it might work out fine, if not a perry pump or Cline regulator would help Quote Link to comment Share on other sites More sharing options...
Jon H Posted April 13, 2017 Share Posted April 13, 2017 Lower is better than higher but a quick look at the manual does confuse me a touch as there seems to be no reason why its not mounted higher up. I would see if you can raise it up to the square cut out in the firewall, or see if the location is better with the engine inverted. Clearly the latter is only an option if the cowl has not bee cut yet Quote Link to comment Share on other sites More sharing options...
.. Posted April 13, 2017 Share Posted April 13, 2017 As above John it should run fine like that. One thing to have in mind with the Saito is that they rely on the low end needle for around 70% of operation so tuning one is slightly different than othe two and four stroke engines (not any harder just different). The 125 is a fantastic motor , very powerful and extremely light too, love mine. Quote Link to comment Share on other sites More sharing options...
john melia 1 Posted April 13, 2017 Author Share Posted April 13, 2017 When i put my finger over the carb or exhaust , the fuel is drawn up into the carb , but it drains back down the pipe again , it doesn't stay there Quote Link to comment Share on other sites More sharing options...
Jon H Posted April 13, 2017 Share Posted April 13, 2017 while not a good sign its the running performance that matters. If you aren't happy then move the tank> it might be a hassle but its only wood, time for the old cut and stick Quote Link to comment Share on other sites More sharing options...
cymaz Posted April 13, 2017 Share Posted April 13, 2017 Posted by john melia 1 on 13/04/2017 19:00:39: When i put my finger over the carb or exhaust , the fuel is drawn up into the carb , but it drains back down the pipe again , it doesn't stay there Would a one way check valve help that? Quote Link to comment Share on other sites More sharing options...
john melia 1 Posted April 13, 2017 Author Share Posted April 13, 2017 Cheers cymaz , I've just ordered that , can't do no harm Quote Link to comment Share on other sites More sharing options...
.. Posted April 14, 2017 Share Posted April 14, 2017 Have you actually run it up in the airframe yet John ? I would defiantly do that before trying to cure faults that may not be there. Quote Link to comment Share on other sites More sharing options...
john melia 1 Posted April 14, 2017 Author Share Posted April 14, 2017 It's already in the model Justin as per opening post Quote Link to comment Share on other sites More sharing options...
john melia 1 Posted April 14, 2017 Author Share Posted April 14, 2017 i knew i should of stuck with petrol and bought a two stroke Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted April 14, 2017 Share Posted April 14, 2017 Posted by john melia 1 on 14/04/2017 10:06:27: i knew i should of stuck with petrol and bought a two stroke oh please no. the noise from these horrible motors is horrendous to the point that I hate a busy club day. I used to love a good turn out. plus without testing it you don't yet know if you do have a problem Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted April 14, 2017 Share Posted April 14, 2017 Woe John, It is very common to have a tank height discrepancy, and it is much better to have this lower than high, as syphoning from a high tank is a nuisance causing hydraulic locks. Your four stroke will have no problem lifting that fuel; it is a quiet motor too and will give great progressive throttling to the Glasair You have the best of everything on your bench right now, and will have great flights Quote Link to comment Share on other sites More sharing options...
.. Posted April 14, 2017 Share Posted April 14, 2017 Posted by john melia 1 on 14/04/2017 09:03:56: It's already in the model Justin as per opening post Yes I realise that John but from your post I was unsure if you had tried to run it or not ? Will it not fire at all then ? Quote Link to comment Share on other sites More sharing options...
john melia 1 Posted April 15, 2017 Author Share Posted April 15, 2017 Had it running for a full tank , takes some starting by hand though Could i put a 16x8 prop on the saito , only reason i ask is it's the only prop i have available, i did have a master screw 16x6 but it kicked back when starting onto my stick and took a chunk out of the blade Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted April 15, 2017 Share Posted April 15, 2017 Why not use that tendency to kick to your (and your prop's) advantage by adopting the reverse flick method? Quote Link to comment Share on other sites More sharing options...
cymaz Posted April 15, 2017 Share Posted April 15, 2017 What does the manual say? 16x6 maybe?? Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted April 15, 2017 Share Posted April 15, 2017 Posted by john melia 1 on 15/04/2017 10:58:23: Had it running for a full tank , takes some starting by hand though Could i put a 16x8 prop on the saito , only reason i ask is it's the only prop i have available, i did have a master screw 16x6 but it kicked back when starting onto my stick and took a chunk out of the blade with the tank lower you may find it more difficult to draw fuel into the carb to get it running but once started it should be fine. a 15x8 is a good prop for this engine a 16x8 is a bit to much I think and if it is a fairly new engine I would defiantly not use it. I always preferred an electric starter as the kick back can be strong Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted April 15, 2017 Share Posted April 15, 2017 You probably know that the 16 x 8 is top end with this motor John, and the motor may even turn it OK when run in, but right now this will overprop the motor and not help run in. The guys have suggested the best start size and to use an electric starter as there is only one ignition to every 2 revolutions, your hand flick barely gets it up to speed, but after the run in is complete, a hand flick may do it Edited By Denis Watkins on 15/04/2017 12:01:13 Quote Link to comment Share on other sites More sharing options...
john melia 1 Posted April 15, 2017 Author Share Posted April 15, 2017 Thanks guys the motor is already run in , by the guy i bought it off Compression is very strong , and as you say that kick back is severe , i cant use a starter at present as i don't have a spinner , tried reversing the rubber insert on my starter to fit on the prop nut but it just chewed it up Quote Link to comment Share on other sites More sharing options...
john melia 1 Posted April 15, 2017 Author Share Posted April 15, 2017 Thanks guys the motor is already run in , by the guy i bought it off Compression is very strong , and as you say that kick back is severe , i cant use a starter at present as i don't have a spinner , tried reversing the rubber insert on my starter to fit on the prop nut but it just chewed it up Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted April 15, 2017 Share Posted April 15, 2017 buy a spinner or dome prop nut and save yourself some agro Edited By Phil 9 on 15/04/2017 12:17:44 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted April 15, 2017 Share Posted April 15, 2017 As I suggested earlier, the reverse flick may be your friend. If you're unfamiliar with the method it's fairly easy and a lively engine like yours should respond very well, as should any reasonably well set up one. This should work on almost any engine, 2 or 4 stroke. In case you're not familiar, you prime the engine so that there's fuel in the cylinder, wind it backwards until you just feel compression, attach the glow (keep body parts clear of the prop arc as it isn't unknown for an engine to self start if you've left it compressed) and give it a smart flick backwards with your stick (or chicken finger with a smaller engine). If you have a spinner, you can often just give it a flick with the fingers. The compressed fuel/air mixture in the cylinder should ignite, giving the piston plenty of impetus to complete the next cycle and continue running - the stick will slip out of the prop arc during the first compression phase... While an electric starter is probably the safest method for the fingers, I often use this technique for smaller engines as my starter is a bit of a beast - or when I just feel like showing off! Quote Link to comment Share on other sites More sharing options...
ASH. Posted April 15, 2017 Share Posted April 15, 2017 I'm always 'showing off'..Back flick everytime usually starts first time. Saito engines need to be nice and wet to fire up. Once you get the hang of it it's a doodle.Edited By ASH. on 15/04/2017 14:07:04 Quote Link to comment Share on other sites More sharing options...
gavinman Posted September 12, 2018 Share Posted September 12, 2018 Just brought a Saito 125a to put in a Seagull Spacewalker 120. Reading the manual it recommends a 16/8 prop but reading this thread it looks like I might be better with a smaller prop .What would be the best prop for this 125a and a Seagull Spacewalker Quote Link to comment Share on other sites More sharing options...
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