Guys . I need a help here. I never use any pump system before, and was trying to break in my OS160 connected with the perry pump, but the engine just won't start. The vent line is open to air, and the needle-valve was set to 2-2 1/2 turn as the instruction says. It flood all the time. I reduced the needle valve, the results was the same. The engine was set up with a header and quite pipe .

Any suggestions and comments is really appreciate.
Thanks a lot.

Mike Shih

You will have to lean the low (idle) needle alot. I carefully screw the low end all the way in and then back out about 2 turns. If it still floods, screw it in a bit more until it will start and run at idle. You can also try to reducing the pump pressure setting by unscrewing the setscrew (mine has about 3-4 threads showing outside of the pump).

Once you get it running it will be easy to adjust and you will be very happy.

The best way is to start the motor without the pump in line and get a decent needle setting. Then put the pump in line and adjust the pump only to get it to run correctly again. My OS 160 / Perry pump set up worked flawlessly, but you will need to lean out the pump quite a bit or it will flood.

Guys, thanks so much !!
I break in the engine today. It is not perfect yet, and I need to adjust more of the low (idle) needle and perry pump.

One thing interesting is that when I reduce the needle valve, the RPM drop ( without connected to the pump) and then stop.
I am guessing it is due to the pressure loose by unplugging the pump line or a bad fuel tank position....?

Mike Shih

Mike:
Yes, once you lean out the low end needle to work properly with the Perry pump, it is going to be at far too lean a setting to work without it at and below the mid-range throttle setting. The other replies are similar to my experience too - I back off the pump pressure a turn or two, go way in on the low end needle and it works great. Have done 3 setups this way now.

Thanks guys
I tried your way today and it works great . I am going to put the engine into the plane and fine tune it.
I guess I need to drill another small hole for accessing the low end needle.

Mike Shih

Keep in mind that as the motor breaks in, the low end may need a touch more tweaking to the lean side......at least that has been my experience.