rc.hackmaster

My Feedback: (4)

i started my os 91 df in my f16 today. ears are still ringing. i have never heard a big 2 stroke turn that hard. was kinda makin me nervous runnin that high of rpm's. kept thinking the fan would shred my plane and my arm . had the needle about 4 1/2 turns out and that thing SCREAMS. i used to race 1/8 buggies with some pretty pumped up 21's but man.... i have never heard a motor scream that hard. cant wait to get it in the air. i am also getting a yellow a4. that one has a pumped k&b 45 i think, turbax fan unit. was never completed. i am going to finish. it also has the sport wings so i think i will fly the a4 first. do you guys think i should put my dynamax/os91 combo in the a4? or leave it in the f16.? i am not sure of the engine size as i dont have it here yet. should be here in a week or 2. i have found out that it is the older a4. so i will be asking q?'s very soon. thanks for reading, doug

Stratotanker

My Feedback: (3)

Was the 4 1/2 turns what it took to make it run rich or was that just being safe? Just curious, my A-4 had very close to that setting using pitot pressure on the fan and I smoked the piston/liner quick. After I went to pipe pressure it was down to about 2-2 1/2 turn range. Don't mean to be nosy or insult your intelligance it is just that the 4 1/2 turns brought back a bad and expensive memory! Being around the cars, I am sure you know how easy it is to burn one of these hi performance 2 strokes up. How about a pic of the F-16!

Chris

JohnnyA

My Feedback: (1)

I agree....4 1/2 turns should be slobbery rich. If it's screaming at that setting, you might have a restriction or need pipe pressure to richen it up....
Johnny

Shaun Evans

Hi,

Yes, it should sound like an old typewriter at 4.5 turns out. If it's screaming and your ears are ringing, these guys are right, you probably have something wrong. Are you running large fuel tubing? If not, switch to large diameter tubing right away. If the setting stays the same, try pinching the line BRIEFLY (like as fast as you can pinch it and let go) and see what happens. If the engine RPMs decrease (even for a split second), then back the needle out even more and try it again. If the same happens, then stop because you definitely have a problem. With that many turns out on a .91, you should get a gradual increase in RPM followed by a momentary scream as it comes on the pipe.

Oh yeah, forget about the pumped 7.5 in the A-4. Use the .91!

DF_Flyer

Doug -

Please do yourself a favor, and get yourself some hearing protection. Not only will it help you to get rid of your nerves around the screaming .91, but it will help you to save your hearing. A nice set of sound reducing ear muffs costs between ten and 30 dollars. Then you can keep on using them even after you've bought that expensive turbine some day.

best regards,
DFF

rc.hackmaster

My Feedback: (4)

ok, will use my shooting muffs nxt time. i WAS loud. uh fuel lines are differing in size. will change to large diam lines. useing pipe press. engine would flame out at any thing under 4 turns when it came on the pipe. did some pressure tests on the fuel system and found lots of leaks. robart pump is mighty handy for pressure tests. also fixing leaks in air system. how long should it hold air? i took it to 80 psi and a hour later it was at 55psi. is that ok? or should i test for mare leaks. fuel system needs new line through out the entire plane. shoud i use the yellow plastic line for gas? has some allready installed but should i replace all? now have digi cam but dont know how to post. could email to someone and have them post. i can make them small. at least i figured that one out.lol. still cant believe the rrr's that thing produced. man! thanks guys, doug

Stratotanker

My Feedback: (3)

as far as the tubing goes, stay with the silicone large diameter and change the brass to 5/32 in your tanks if it is not to big of a pain. How are your tanks set up?, if they are in parallel make sure that the lines from both tanks are identical in length pressure and fuel. I don't really know on the pressure test as I have never tried that. I would say to just R2 all the tubing and safety wire all the connections or stretch a 1/4'' piece of tubing over the lines to keep air out.


Chris

rc.hackmaster

My Feedback: (4)

yep tanks are in parelel. lines are = . there were many leaks. will change lines this weekend. just noticed you (stratotanker) are from spokane. you ever go to jets over whidbey? i will be attending this year. f16 looks ugly right now. paint half stripped and needs some glass work b4 i prime. thing was kinda a basket case when i got. but working out the bugs slowly. thanks, doug