stssa

after a 3 weeks vacation to northern california im finally back. so here is the latest update. I ran the magnum today. I got it to idle around 1600rpm w/o glow. with glow It idles around 1400rpm. and full throttle I can get it to run around 7000rpm with a 18x6 prop using %15 nitro with castor. These numbers are with the high speed needle 2.5 turns out. when I set it to 2.0 turns out it does 7400rpm. Im waiting on some parts from china since globalhobby doesnt have the parts I need. I will do a complete rebuild on the right side. hoping it will get better if not im still planning to use it. I love the sound of this thing.

Rudolph Hart

You can't beat the sound they make it's awesome.Flew one in a taylorcraft last sunday.

stssa

I have changed out the right side, sleeve, piston and ring. Now slightly more compression than the left side. right now its running 18x6 at 7700 rpm and 16x8 at 8200 rpm. I will go ahead and replace the left side sleeve piston and ring and try to get more out of it.

Im still upset at the fact that right side still smokes less (leaner) after a 10 min run, right head reaches 179f while left side is around 135f which is a huge difference imo.
im thinking about using a hotter glow plug on the left side hoping to burn more. What is the hottest 4 stroke plug can i use other than OS F?

also, right head valve lash is adjusted to .20mm and left side is at .04mm. trying to compensate for the lean condition.

kenh3497

Reffering to the cylinder head temp..... It's not unusual for one cylinder to run hotter or cooler that the other using a single carb and a manifold. This is true for ANY engine with any number of cylinders that is not fuel injected and even fuel injected engines can have this problem. It's all about airflow! Nothing you can do about it except live with it. You might check the intake manifold to make sure something is not obstructing it?????

Ken

SrTelemaster150

That's exactly why I opted for the dual carbs when I bought my Saito 300 TTDP. Every single carb Saito 300 I saw in use was having problems balancing the cylinders. (at least at idle anyway)

It took some fiddling W/the dual carbs but I was able to get both cylinders balanced. I had to set the right cylinder carb richer on the idle to get even running & similar "smoke" on the idle & midrange. I'm not sure how the HS needle adjustments compare as the HS does not offer a "visual" reference like the LS.

stssa

there is no obstruction inside the manifold and this engine alternates on the intake strokes so its not like one side is sucking more causing the other to starve. I've read lots of postings here and pretty much everybody is having this problem. Like I said Im hoping to get the temps. closer when I use one hot and one super hot glow plug.
if that doesnt work, im going to do a twin carb set-up however, I dont know where to start. What kind of carb can I use and how to do the adjustable linkages on it? Do you guys know of anyone who has done this on a magnum 160 or an os 160?

Rudolph Hart

I've heard that some guys are running the os carb off the gemini 160.