FNQFLYER

With all the run in guide lines listed above I always remember the advice I got from the guys at the Saito factory. Follow the guide lines, (usually richer than normal) listen to the engine and gradually lean it out (while following the break in guide) as and when the engine "tells you" Each engine is different and will take different amounts of time to truly break in. Though I do follow the other bit of advice and I did have (and will soon have again) a big trainer that I could mount the engine to complete the break in process in the air. Gentle circuits (boring but ultimately productive) are the go, not flat out but varying speeds and rpm range, use a gentle prop (MS in the middle of the recommended range) and no "hot dogging". Works for me.

Hobbsy

My Feedback: (102)

FN, what is your real name if you don't mind. I may have been playing the devils advocate a little, I actually tried four gallons of WildCat 2/4 which is 18% synthetic and it worked fine. Of course 4 gallons doesn't exactly qualify as a long haul but it ran really well. More importantly .When I would pull a backplate after a few days the internals were still wet.

blw

My Feedback: (3)

a big 10-4 on all of that good advice.

Well, maybe except for some wide open time. Still, just like you said, the engine is telling you things and every engine has it's own personality.

FNQFLYER

I have been lucky in my life, people paid me to go to exotic places (and the USA) and I learnt lots in these places. Hong Kong (The World Model treasure cave of the 90"s) Saigon in the 90's and the beginning of ARF's Japan, Saito and JR radios. Listen to a lot of people in these places and gained heaps of "knowledge". All of which has stood me in good stead. One thing I always remember "you make your own choices as to what you do. Learn to live with them no one else has to"

FNQFLYER

hobbsy how do i private message you

w8ye

My Feedback: (16)

Click on his name and a window will pop up where you can PM him.

cubfloater

My Feedback: (5)

Update! A few pages back I mentioned my stuck exhaust valve on my Saito 72 and after soaking, tapping, pressing, PB blaster, WD40, fuel, bigger hammer you name it nothing worked so I took the jug off and took out the valve and it was so covered with residue I had to soak in Acetone and clean with steel wool and emory cloth. Got it back together and seems to work fine, just hope it runs. And this from using Coolpower 15% Nitro and no caster oil. Engine doesn't have a lot of run time on it at all. So I'm trying adding some caster to my fuel. Thanks for all the tips. It's on a Super Sportster I'm ready to get back into the air. Jim

Cycotravlr

Good evening Gentlemen.

This is my 1st time on this thread so my questions may seem to be a repeat. I recently picked up a Saito FA-91 at an Estate sale for $30. My thoughts are that I will overhaul it and have a nice engine for my future build of a Sterling Stearman PT-17. Can anyone point me in the direction of a Saito repair manual for this engine (if there is such a thing)? You would think that there is some sort of reference manual out there. I am eager to start and looking forward to any information offered.
Thank you,
Perry

NM2K

My Feedback: (14)

Truthfully, I would go with a Saito 1.25 were I expecting good vertical performance from a 7.5 lb model.


Ed Cregger

SrTelemaster150

Adding castor will NOT reduce exhaust valve deposits. You must be running overly rich. I ran over 50 gallons of Cool Power through a Saito 150 W/O any problems.

cubfloater

My Feedback: (5)

you are correct! I do run it rich. I thought it would make your engine run cooler, last longer less chance of burning it up and just have to change glow plugs more. Guess that may be true with 2 strokes? At least that is what I have always heard. So not correct? Thanks for straighening me out.

w8ye

My Feedback: (16)

You just went a little too far with the rich bit. Look at it this way. If you drink too much water, you'll drown.

cubfloater

My Feedback: (5)

Perry, there are some good videos on YouTube regarding tearing down, rebuilding both Saitos and OS Surpass engines. I'm about to put bearings in one of mine and feel confident in doing it after watching two or three videos. Plus if you have any questions on it post it here and these guys are great and will help you out right away as you can read in my post just above here! Good luck.

Jim

cubfloater

My Feedback: (5)

Well I was about to that is for sure and all the rest of mine as well. So what is it 2 - 300 rpm backed off from peak with a tach for the optimum?

cubfloater

My Feedback: (5)

drown that is, tried to quote w8ye!

Jim Branaum

My Feedback: (3)

Rolling up all of your earlier comments and questions into one because I am lazy. You do not want to use excess fuel to make any 4 stroke run cooler. It has a natural temperature it LIKES to run at which is hotter than most 2 strokes for several reasons and using fuel to cool it loads the exhaust circuit up with coke - which is that gooey stuff you see that has been burned. Four strokes NEED to run hotter to keep the plug working. They run hotter because there is not a power stroke every cycle, which is when they cool down. You cannot tell if a 4 stroke is about to croak because of over lean without a tach which will show you the rpm dropping just after you hit peak but well before things get too hot.

I tune for max rpm and then richen it about 200 rpm to keep it from going lean on the verticals. The problem is that you must use a tach, our ears just ain't that good! It is amazing to see how much more rpm you get and not hear much in a note change.

*I* would NOT add castor because I have had some negative experiences with castor and 4 strokes. There are many who swear by it but I swear at it.

YMMV

Good luck.

blw

My Feedback: (3)

The low speed needle is the most important one on a Saito.

frets24

My Feedback: (15)

The 1.25 should haul an 8 pounder unlimited vertical with power to spare. I'm running an Fa-125 on this Ki-61 with an AUW of 14.5lbs on a 71'' wing and it will hold a 60* climb forever. It's running a 15x8 MAS classic composit prop using 15% cool power at 9800rpm...May need to go to a 3 blade to back it off a bit, can't really add too much more diameter due to clearance and a 10'' pitch would be unlandable. (The Graupner in the pic is just a display prop)

Hobbsy

My Feedback: (102)

The drown would refer to the plug drowning from a too rich mixture, as JB said the fourstroke needs to run on the hot side to keep the plug lit and to gain thermal efficiency. In my book 300 rpm rich is too rich, 200 rpm, set with the tank half full is more better, or 100 rpm rich of peak with a Cline regulator.

Frets, would a 14x7 three blade Graupner fill the bill?

Papa51

My Feedback: (3)

Good Evening,

I have serveral Saito's, some still NIB but mostly have been running .50s in various aircraft for about 10 years. I recently took a NIB .80 out and installed it in a Midwest .60 P51 Mustang. For the life of me, I cannot get this engine to stop knocking and pre-detonating! I pride myself on being able to tweek a Saito engine and get it to run great, but this .80 has got me scratching my head! This .80 is probably a 1990s version. I've used 10% and 15% nitro fuel with half castor and half synthetic oil. This is what I've always used in my .30s and .50s. I've tried different plugs with little or no relief. Obviously, this engine is of higher compression ration than others I have had. Should I try shimming the jug or just go to 0% nitro? Any help I can get will be appreciated.

bchapman

Just received my new FG-21 and was wondering if any of you had any tips for me. It's my first 4 stroke engine.

Thanks!

Hobbsy

My Feedback: (102)

My guess that it's way rich, I hate working on engines in the plane, you can't see what you're doing. If you have a test stand get it out where you can tell what's going on. That will help a lot.

Jim Branaum

My Feedback: (3)

Close BOTH needles and start all over. 3 turns open for the high end and 2 for the low end and give it a go. My guess is that you will probably wind up somewhere around 2 1/4 on the high and 1 5/8 on the low, but YOUR engine needs your tuning with a tach.

mike109

G'day hsukaria

The 82 is a recent design. The 91 is from an older, now mostly extinct, series. The 91 has not been made for several years. I think if you want a 91, then100 is the current replacement for the 91.

I have an 82 in an Astrohog and it does not overpower it. I also have a Four Star 60 which originally flew with a 72 but now has a 100 in it and flies much better.

There is also the 115 which I believe is quite compact. A friend had one in a Pulse 60 and loved it. I think it is the same size as the 100 or am I confusing it with the 125? I am sure someone else will chime in and correct any errors I may have made here. The 125 would certain liven things up in a 60 size model.

Cheers

Mike in Oz

Pete Bergstrom

Mike - Actually the 91S is still being manufactured and available new.

The 91 and 115 share pretty much the same case and bolt pattern. The saito 100 and 125 share pretty much the same case and bolt pattern.

Pete