jaybird11

WONDER IF I CAN GET IN?? I HAVE A 56,82.AND A 125 AND WILL NEVER RUN ANYTHING BUT A SAITO!

blw

My Feedback: (3)

#550 colmor

#551 jaybird11

You have some good engines.

thrashin

Hi Guys,

I have a 2mtr Cap 231 with a saito 120s in it and it's got good performance, but limited vertical pull. Can do nice big loops but can't hover or keep climbing up. I am thinking of replacing with a 150bk I have seen come up for sale. Would I expect a marked increase if I switched to the 150?

Cheers.

w8ye

My Feedback: (16)

The 150 will turn a 1 inch bigger prop at the same rpm as the 120.

RCWI

Im sorry about the confusion... the 85 Deg was the temp outside, (air temp). didnt check the engine temp. And im still running the plug that came with it.

thrashin

Hi there, so I should not expect this plane to be transformed by replacing the Saito 120 with a 150? i.e. do you believe I will see a marked difference?

Cheers

w8ye

My Feedback: (16)

There would barely be enough difference for you to notice. You need to go with a Saito 180

scratchonly

At 85 degrees and high humidity you will notice a drop in power, as there is less oxygen in the air therefore you can't burn as much fuel.

RCWI

Thank you, I was really wondering if I had something tuned wrong or if there was a problem with my engine>>>

thrashin

That's the answer I was looking for.... thanks! So.. anyone out there got a Saito 180 in good nick that they're looking to offload?? ))

iflyfisher

Got the issues with the Saito 150 resolved this evening. Solutions to some of my issues may be obvious to many of you, but I'll share my experience with the forum nonetheless.

Slipped back out to the field this evening after having added a separate fuel dot for the vent. I started with the HS needle open at three turns and had some success getting the engine up over 8K rpms, found the peak and backed the needle back out a touch to lower the rpm. I thought, cool, I have it. I then ran the rpms up a few times and back down. All seemed well until I opened the throttle full and left it there for a minute or so. The engine loaded up and died. I went through this a couple of times, each time resetting the HS needle. I just couldn't figure out what was going on, so I decided to check the LS mixture. As I peered into the cowl, I noticed fuel running out of the carb. I couldn't figure out why the carb was dripping fuel then it dawned on me about the one way check valve I had put in the vent line. I unscrewed the HS needle and got a geyser of pink Omega a good two inches high. I had never used a one way valve before, but thought I wouldn't hurt. Well, with these engines, apparently it does. I was getting so much pressure built up in the tank that carb couldn't properly mix the fuel and air. My issues last week of not being able to unload the engine were due to this blasted valve. Once I took the valve out, the engine ran up great, and I was able to set the HS needle without a hitch.

I ran the engine up a number of times and all seemed well, so I brought it back down to tweak the idle rpm. It seemed to run fine but then would quit. I restarted a few times with the same result. Idle 30 seconds or so then quit. I backed out the LS screw a quarter turn, but that wasn't enough, a little more, and I had a nice consistent idle at 2800. I let it run for a good 10 minutes, occasionally running up the rpms then back down. The Saito was finally dialed in, but I was out of daylight, so the Ultimate has to wait for yet another day for its maiden.

Thanks for all the tips.

w8ye

My Feedback: (16)

Glad you got it. I bet, looking back, there was nothing to it??

Sometimes it's mighty hard to get from point A to point B.

kryptonite

There were a couple of comments a few msgs back about the Saito 125 and props.

I've experimented with a number just last week and keep coming back to the APC 16x6. I'm getting 9100 rpm on 15% nitro and using a digital fish scale this prop packs the most punch in terms of thrust - something like 14 lbs! On another forum, the same consensus was reached - the APC 16x6 consistently provided the most thrust with the Saito 125, so that is easily the best choice if you want to do 3D.

thrashin

Can the same be said for the Saito 120s - a 16 x 6 prop is the best choice? Is there much difference in performance between the 125 & 120s?

w8ye

My Feedback: (16)

The original reviews proclaimed the 125 to be more powerful. I do not have a 120S. I have a 125 and a 150.

My 150 does a APC 16-8 at @9200

RC Specialties

thrashin,

I have both and can't tell any difference in the two engines. I have to say that the 1.25 has not been airborne yet. The performance varies between airplanes. To accurately compare, they would have to be tried on the same plane. However, on the bench it doesn't seem to have any more power. The 1.25 is fairly new and seems to like the 15x8 APC better than the 16x6. There is not that much difference in the props. Maybe it will change with more run time.

Jim

Ken6PPC

Don't forget the weight difference between the 1.20 and the 1.25!

The 1.20 weighs 10 ounces more than the 1.25!

Let's assume you have two identical engines, spinning identical props, at identical RPM's, mounted in identical planes. The lighter "ready to fly" plane will perform better, simply because it has less mass to move through the air.

Unless you need the extra weight in the nose to balance your plane, the 1.20 will have quite a bit lower performance as compared to the 1.25. This is irregardless of how you measure "performance" - acceleration, vertical flight, 3-D, or whatever.

Whoops! I just thought of one area where heavier weight might be an advantage - if you are trying to see how large a hole you can make in the ground. (Like I have done with a few of my planes!) HA!

blw

My Feedback: (3)

I think that Saito rates the 1.25 as having 10% more power over the 1.20.

RC Specialties

Ken,

You are absolutely correct about the weight issue. You would see a little increase in performance with less weight. Maybe this is where they get the 10% more power. It would have some increase, but I am not convinced it would be a notable difference. Hey, every little bit helps. One thing I have noticed is the fuel consumption. My 1.20 drinks the fuel like crazy. The 1.25 seems better on fuel.

Jim

Jimmy Hoffa

My Feedback: (3)

Does the "dot" on the connection rod go towards the front (prop) or rear (carb, backplate)?
Phillip

Ken6PPC

Jim, I think that losing 10 ounces would make quite a difference in a fairly light weight plane.

If we are talking about a six-pound plane, that would be roughly 10% of the total weight. If the plane is eight pounds, it is only about 8%. In a ten-pound plane, it is only 6.5%. So, the heavier the plane, the less you would likely notice a performance increase by losing 10 ounces.

If you can reduce the weight you have to pull around by 8% or more, I think you WOULD notice the difference!

Of course, all of this is pure speculation, since those identical planes I wrote about could never exist. They would both HAVE to be balanced, and the lighter one might require the additional weight up front anyway!

w8ye

My Feedback: (16)

The "DOT" goes where ever it wants to. Ignore it.

What's important is the chamfer in the ID of the big end of the rod. This chamfer goes towards the crank.

chrome350

My Feedback: (66)

Hi All,
I've got a Saito 100 with about 2 hrs runtime on it, 15x6 APC, OS F Plug, using 30% cool power heli fuel. I've slowly tuned the engine to lean it out to where it's been running perfect. Then I had a dead stick. I found that the glow plug had burned out and the muffler had loosened up. I replaced the original Saito plug with an OS F plug and tightened the muffler. After doing this the engine would not idle well. The low end became so rich that I had to turn in the low end screw 3-5 turns. Originally after I first tuned the engine, the low end screw was a little below flush with the throttle arm. Now after retuning, it's very far in, like an 1/8 of an inch. Is ther anything else that could make the low end become so rich all of a sudden??

Thanks,
Larry

RC Specialties

Ken,

I don't disagree with you. I am going to try it in my Ultimate. With the 1.20 I had to add tail weight. In this case it will make a difference. I will let you know.

Jim

w8ye

My Feedback: (16)

I've experienced the low end rich syndrome with two Saito's. Don't know the cause? Seems to have something to do with the spray bar? That's what it took to fix it.