Saito 82 Tuning

[Scruffmeister]

 

Hi guys - struggling tuning my Saito 82B engine, appreciate any help those more experienced with four-stroke engines can offer (this is my first).

 

 

Propeller is a Graupner 13x7. Fuel is 15% nitro, 20% synthetic oil from Souther model craft.

 

 

I've followed the (extensive) run-in procedures to the letter, but in a nutshell I can't seem to get a nice reliable low-speed idle. The best I can manage is something that stutters and coughs, occasionally resulting in the engine backfiring and restarting backward!

 

 

I took a video of it showing speed through the range, effect of quick throttle change. At end of video (around 25 seconds in) you can see what happens when I close the throttle and let it idle ... not good.

 

 

Any advice where to go from here? I haven't touched the low-end needle at this point as was my understanding that is was fairly well set at factory. High-speed needle is open 3.5 turns which (with my unreliable tacho) gives my an RPM of around 9500.

 

 

Here is the video!

 

https://vimeo.com/63751899

 

 

Thanks in advance.

Edited By Scruffmeister on 10/04/2013 18:34:23

[ken anderson.]

hello SC ........you normally find that the bottom end needle will need a slight adjustment done to it to get a decent tick over.......i would make a mental note of where it is and screw it in(no more)than 1/4 of a turn......from what you are saying it sounds as though its too rich......you'll notice a difference straight away......you may need to alter it very slightly...some more.....and you'll need to retune the main needle also..........take your time when doing the alterations......i do it with the engine running .....

ken anderson ne...1... 4 stroke dept.....

[YakMad]

13x7 is too small for the 82, best prop is APC 14x6, the Saito 82 is difficult to tune correctly, I find that the low end needs to be slighty rich to get it to throttle correctly, I tried mine on various props it would run ok on a 13x8 but the 14x6 transformed the engine, it really needs 20% fuel to perform at its best, I know this could open up the "my engine does not need nitro" debate but all four-strokes love nitro the 82 just pefers a little bit more. The idle needle on a Saito engine affects about 80% of the throttle range, if you don't believe me take out the main needle and watch the engine continue to run without it, so long as the throttle is not opened fully.

[YakMad]

Sorry should have added the low end needle on all Saito engine is set very rich from the factory to ensure you don't get a lean run while running the engine in, it will need adjustment as Ken has stated above.