Aussie Glow

Gidday Jon, attached is a picture of a Saito FA91 big end ( the Saito in pic #2 ) it doesn’t appear to have a bushed big end. I don’t know this engine history or age as it was given to me in bits and pieces some years ago and not sure if all Saitos use an un-bushed big end. I’ve never had the pleasure of owning a Laser engine, always used Saito 4 strokes and one sweet old OS rear cam 90 engine in a trainer used for ab initio students on club days that just keeps on going. When a Saito finally wears out, I’ll look for a Laser. 😃

Photo 1, a bit hard to see under the cowl but that’s it. Photo 2, the black dot is where I’d drill and tap thread, making sure that you don’t drill too close to the lifter bore, very self explanatory when you have the cam box apart. I use the existing nipple, block the hole in the rear case, make sure the nipple doesn’t screw too far in as it could hit the cam lobe so when tapping thread, make it a tight thread, with the breather tube exit it with some brass tube into the airflow under the cowl or attach to an UC leg, no more oil on model. Works very well for me on 3 Saito FA 91s Good luck. 😃

Hi Guys, getting back on to the topic regarding oil in 4 stroke glow engines, call me mad but I for many years have only run 8% good quality synthetic oil, 10% nitro and 82% methanol and just a shade rich mixture on peak RPMs with a full tank so as it’s probably peak lean on a vertical pull up and when the tank is nearing empty. Im running 3 Saitos FA 91 and 1 very old OS rear cam 90. The only maintenance I’ve done on these high hour engines are the crank bearings and tappet settings. Tappet settings on the Saitos, I set 0 to max 1 thou clearance. One modification I’ve done on the Saito engine is to put the breather nipple on the side of the cam box so all oil vapours go past the big end, through the main bearing with seals removed and exit out lubing the cam lobes and lifters. The old OS 90 breather is next to the cam box/ shaft. Providing you are running a good quality sealed front bearing and the breather is exiting out into the airstream, the model stays remarkably clean and no need to wipe down after a solid day of flying. One of the Saitos has consumed at least 160 -180 litres of fuel, all original apart from usual bearing replacement, I’ve never had the piston out of its barrel so don’t know how much carbon build up but exhaust valve is visibly clean, still has great compression, don’t know if you can actually wear out one of these engines if they are well looked after. The main reason I run a low oil content is it gives very reliable slow idle and super easy starts and no slobbery oil dripping off the model, I have gone down to 5% nitro but I like to keep my engines running just a bit harder to give the 2 strokers a run for their money. I definitely wouldn’t run this low oil content through a 2 stroke, reasons previous mentioned. I’d certainly recommend 10% oil mix with in a Saito with the breather moved next to the cam box, they just run so much better and cleaner. Previous experience with Saitos is the cam does run dry when the breather is at the rear of the case. Thats my 2 bobs worth. Adios 😃