Ok here is the brief story, I just recently had one of my favorite planes stolen at a local field,The plane had a saito 100 on it and it was just the best engine I think iv ever had, I have 3 that are just incredible engines but the problem is I didnt do any of the tuning a friend of mine has always tweeked mine and set them up to run there very best, But a few months ago I lost that friend to cancer and I could just kick myself for not paying attention to what/how he did everything to these 100. I just finish building a funtana and I put one of my new 100's on it and I must say I'm having the worst time with it I cant get it to do anything, for example when I start it if I move the throttle at all it wants to die, so I'll mess with the needle alittle and maybe then I can get it to move alittle more but then it dies but then something else like I'll take of the glow nicad starter and then it dies again, so I'm so confused, I dont think there anything wrong with the glow plug cause the engine is bran new, When I put the engine on a test stand to break it in it ran fine but then again I wasnt cycling the throttle, So can anyone give me a good starting point on this engine and and any other info would be great, I really wish I would have learned alittle better from my friend but hopefully you guys can help. Thanks alot

Randy

It sounds like you are really rich! Your symptoms indicat that you have too much fuel on the low end. First off we need to know how many turns out you are on the hi end. Lets strart with 4 out and go from there. Start the motor, with the glow attached, try to advance the throttle(slowly!). If it dies then turn the hi speed needle in 1/4 turn and try again. Continue until you can get the motor to full power. Once you have full power, remove the glow and tweek the hi speed for max rpm and then back off 500 or so. Bring it back to idle and try to accelerate. If it sputters or dies then kill the motor and turn the low speed IN(clockwise 1/8 turn. Start and with the glow on go to full throttle and readjust to peak -500. Back to idle and repeat low speed adjust. Continue this until you have a reliable idle, good transition and good hi speed. Dont forget the steps... you need to readjust the hi end after each low end adjustment. Take your time and only do 1/8th on low end at a time.

Let us know and I'm sorry for your loss (plane and especially your friend!)

Sorry to hear about your loss.

Saitos come factory set very rich at the low end for running in (which should be done at below 4000 rpm).

Have you run it in fully yet? (30 minutes at the above speed) you will probably have to leave the glow clip connected to prevent it dieing.

Once you have done this, you can start leaning out the low end. All my saitos (I have had 3 so far) have needed at least 2 (yes 2) turns in before getting something like a consistant idle without the glow attached. Turn in half a turn at a time at this point.

When you get to this point, follow deputydogs description of what to do. You will probably end up going in for at least another half turn, and remember to reset and check the high end as well.

Once you have done this, you should have a good running engine, and can now go fly if you wish, but keep it rich at the high end, but there is still more to do to get the best. You need to check and reset the valve clearances, usually they are factory set very conservitively, great for running in, not so good for performance. I will assume that you don't know how to do this either. use the instructions in the manual as well as my description.

When you get home after those first flights, and the engine is nice and cold (v important, valves must be set when the engine is completely cold) take the valve covers off. Use the tools supplied with the engine as they are metric, you may only have US sizes. First make sure that it is all well oiled in there. Then turn over the prop a few times till you get to top dead centre on the compression stroke, as this is the point that both valves are fully closed.

Use the little spanner and hex key to undo the adjustment bolts on the rocker arms. The spanner is for the lock nut that holds the bolt in place. Use a feeler guage to set the clearance, this clearance is at the other end of the rocker arms, between the arm and the top of the valves. From memory you don't get a feeler guage with the 100 (you do with the 72). If you don't have a feeler guage, get a set from an auto supply shop. I can't remember the clearance in inches (we have metric on our side of the Atlantic, where it is 0.05mm to 0.1mm), but I think it is given in the manual.

The way I use the feeler guage is to use the one for the smallest gap (I use 0.05mm) and keep turning in (clockwise) the bolt till it grabs the the feeler guage, then open up a little bit so it is free again. Then turn over the prop to reset the rockers, back to TDC, and test again. This time check that the smaller feeler goes through easily, and then check that the gap is not too big by trying a feeler at the top end of the suggested range (in my case 0.1mm), to see that it does not go in, unless forced.

Now tighten up the lock nut on the bolt. Hold the hex key in place while doing this or you will change the setting. Turn the prop over once more, and give a final check. Then set the other valve using the same method.

Next time you fly, you should have a Saito 100 just like the old ones you loved. It may still need some fine tuning on the low end, and I usually check the valve clearences again after about another gallon has gone through it, just to be sure, but this should not be necessary if you did it right first time. The valve clearances should be rechecked every now and then. I do it about once every six months or so, but others here on RCU say once a year is enough.

Hope this helps. Let us know if you have any further queries, or need clarification on a point (I have covered a lot of ground). It takes a little while to do this, but it is worth it.

Thanks alot Sprink , That was a lot of info so i'm just trying to digest all of it...





Take care

Randy

Check this website out [link=http://saito-engines.info/]Saito Tips[/link]. It's got a lot of good info.

The reply's above also have good info. My low end on my 100 was very rich from the factory. It took several turns to get it tuned. Runs like a top now. Great running engine.

Print it off and file it if you need to refer to it (I don't know about you but I don't tend to have a conection to RCU at the field[&:])

I completely forgot about the Saito info site. It is a good resource for all things Saito.