Hello everyone, has anybody used a perry pump on an O.S 1.08? and if yes could yuo tell me how it works, and give me the tips on it. I´m planing on using one on mine so I can place the fuel tank back on the C.G of my plane. Thanks much!

You will find the the carb on the OS108 will not allow you to adjust the low speed low enough to get it real clean unless you bleed off some pump pressure by running a bypass. I also removed my restrictior sleeve as it is not needed with a pump. See this thread for details.

http://www.rcuniverse.com/forum/m_28...tm.htm#2835580

With a pump my OS108 spools instantaneously. Click here for wave file of it spooling with a 16 x6 prop. http://home.comcast.net/~ccrsfield/108FSR16x6zing.wav

Thanks my friend, I would apreciate if you explain me clearly about the Y on the fuel line so I can do it just like you did, maibe with a grafic or so! I am down in Venezuela, I will let you Know the results. Expect back from you soon, I will wait for your reply to make my instalation!!!!!!!!!!!!!

Start with your low speed leaned all the way on the 108 and the pump fairly lean. My high speed needle is 2 turns out and not sensitive. I run 15% fuel.

You can T in to fill the tank at #3 or #6 below. If you T in at #3 (clunk) you will be able to drain the tank easy, but if you have an air leak you will have problems. Enjoy.

Hey STG! This is the first time I have heard mention of stretching the spring in the pump. I suppose this is to increase pump pressure. Could this be part of the reason I need to use the restriction in the bypass line? That engine is going back on my flying wing, and the tank is close to the engine. It will be interesting to see if it acts any different with shorter fuel lines.

raimondi STG and I have the same setup, with the exception of the muffler. He's getting a few more revs than I am with a bisson pitts, but the engine runs sweet with this setup. It will take a little tweaking to get it right, but it's not much work, and it is definitely worth the effort. I had to restrict the bypass line to the tank to get enough pressure to the main needle. Once I did that, all is well.

I forgot that was part of the instructions. Not sure what this accomplishes? I have not done it. Sorry for the confusion.

I think the Jtec does give better numbers as I seen a 300 RPM increase from the stock muffler. It is very loud though. I am thinking seriously about trying one of those Turbo-Jett mufflers. Might pick up another couple hundred and quiet down.

My 1.08 gets compliments on the sound it makes when I fly it now. The 16-6 prop pulls better at lower revs, and with the pump working right, it never sounds thin or tinny like it used to. I am totally satisfied with the performance of the engine. I just need to put it on a lighter plane by about 1 lb to get the performance I want. Now I'm itching to get to that G2300 that's still in the box!

I picked up a 1.6FX new in box in the market place so I looks like I will not go the ST for now.

If you are going to use a pump on the ST2300, my guess is that this bypass system will be the way to go.

I'm sure you are right about that. I'll be trying it stock first, just as a baseline. I think the pump and bypass system is probably what will keep me into the two stroke motors. The four strokes don't have much at all on a well set-up two stroke, not even sound.

I love the 1.60, but my budget just wouldn't allow it. My friend has one without a pump, and it sounds a little thin in the midrange, even though it is plenty rich up top and idles well. He's got it on a 15 lb scratch built model. Hauls it out of sight, no problem. You'll have to use a throttle stop with the F90 to keep the wings on! It'll be a whole new airplane, and much more fun to fly.

It was to good of a deal to pass it by in the Market Place. Not sure if it will go in the F90 or the Yak. [&:] I sold the YS110 that was in the Yak--just did not like the cost of high nitro fuel.