This weekend I run my Poulan again. This engine is loud - I need some better muffler. The good thing is, that the engine test stand was far away from the pits, so nobody was pissed when this sucker run WOT for straight 30 minutes.

The results were quite optimistic. I run "lean fuel" (1 part of 15/18 Power Master glow fuel = 5 parts of Chevron 91 oct gasoline), that is very convenient as 15%nitro fuel is the most common used in USA and available in almost every hobby shop. Starting by hand just sucks. Not because it doesn't start, but because it starts backwards almost every time.[:@]. The engine starts after 4-6 flips but if 9 of 10 times it starts backward, that makes 40 flips to start it. After a couple tries I grabbed starter and the next second the motor is running pushing the air over the cylinder.

After I tuned the carb I got steady idle 1900 rpm and WOT 7600 rpm. The head temperature (it was over 90 under the sun) was about 215 F. After while I noticed that rpm dropped to about 7200 rpm. I checked the fuel and temperature and everything was OK. Then I connected voltometer to the glow plug suspecting burned plug, but I noticed that my battery run out giving out about 0.6V. I disconnected the battery and let engine run like that. The engine keept running 7200 rpm without missing a bit. However idle was not good any more. Going below 2500 rpm I was risking the engine would die. Also transition was not smooth. After long idling at 2500 rpm it took a long time with slowly opening the throttle to get full rpm again.

At this point I had about 2 oz fuel left. I opened the throttle and let it run till dry. It took 12 minutes WOT to burn this fuel. The mileage is really impressing. I checked the glow plug - still intact. I'm quite happy of this test. The next time i will run it, it will be in the plane. I found very good candidate for this engine: [link=http://www.spadtothebone.com/SPAD/corocub/Corocub_1.htm]Coro Cub resized to 90 inch span[/link].

The other problem I have with this engine is the muffler. I had to run gutted stock muffler (loud like hell) because I need to fix my regular muffler again. I got this muffler from Whackerengines (the one I showed in[link=http://www.rcuniverse.com/forum/fb.asp?m=3196537]Step by step converting Poulan 25cc FL trimmer [/link]). Two tubes supposed to be screwed into the muffler's body and secured with tail pipe sealer. This doesn't work and whatever I do, both pipes vibrate loose after few minutes of running. I need to find some shop, that can weld aluminium to secure these pipes once forever.