wallboy Posted April 25, 2012 Share Posted April 25, 2012 I started off with a completely standard Rad MXL but wasnt happy with the flappy props and little thrust so I decided to have a little project. Take a look at the following photos which ive taken along the way. Quote Link to comment Share on other sites More sharing options...
alan_k Posted April 25, 2012 Share Posted April 25, 2012 Looking very good so far Quote Link to comment Share on other sites More sharing options...
Guest Posted April 25, 2012 Share Posted April 25, 2012 Nice job I had a RAD a few years back and also tried to fit a primer bowl which also (did not work) I can only think that the daphram in the carb is not strong enough to do the required sucking with the added pressure of a primer bowl full of fuel. ?? SW Quote Link to comment Share on other sites More sharing options...
nigel_d. Posted April 25, 2012 Share Posted April 25, 2012 Why wouldn't the primer work, do you mean the fuel wouldn't go up when you squeezed it or the engine wouldnt run with it in place? Just checking that your aware of the need to depress the carb diaghram whilst squeezing the bulb. Nige Quote Link to comment Share on other sites More sharing options...
Guest Posted April 25, 2012 Share Posted April 25, 2012 Thanks Nige That I am aware of, priming is not a problem, but it will run like a bag of poo and if I remember correctly not exceed half revs no matter what you do to the carb settings. SW Quote Link to comment Share on other sites More sharing options...
nigel_d. Posted April 25, 2012 Share Posted April 25, 2012 This reminds me of a debate that me and Pete got into when I mentioned that my old Rad was a pig to start when it only had a couple of litres in the tank. I concluded that the pump was limited as to how far up it could draw fuel, in that a full tank was easier for it, Pete disagread saying that such a carb could pull much higher. Now I would say it is not so much the height but the inertia of an excesive amount of fuel in the pipe/bulb that could be the problem causing running/starting problems. The idea being that the fuel "jumps to the attention of the suction pulses" when there isnt much but becomes more slugish to rapid movement when there is a lot of it. Nige Quote Link to comment Share on other sites More sharing options...
wallboy Posted April 25, 2012 Author Share Posted April 25, 2012 The primer bulb pumps fine but once I connected it to the fuel line and stated pumping, the bulb was really hard and required 2 hands to pump and it sucked a little bit of fuel in then pushed it back out into the tank. Reading the comments above I think I may have forgot to press the decompression button I will get it out and give it another go when the rain has buggered off Quote Link to comment Share on other sites More sharing options...
nigel_d. Posted April 25, 2012 Share Posted April 25, 2012 Sorry Simon, my initial question was meant for the other chap (I'm sure you already knew about diaphragms) but nonetheless raised an interesting problem. I wonder if my theory is correct. Nige Quote Link to comment Share on other sites More sharing options...
Guest Posted April 25, 2012 Share Posted April 25, 2012 Looking at the above, I would say so dude. SW Quote Link to comment Share on other sites More sharing options...
wallboy Posted April 25, 2012 Author Share Posted April 25, 2012 [youtubevideo]http://www.youtube.com/watch?v=efCrg-u7WbQ[/youtubevideo] Slide show with video at the end Quote Link to comment Share on other sites More sharing options...
jock Posted April 25, 2012 Share Posted April 25, 2012 looks good.were abouts in worcester are you.did you make your own prop,sean has a rad arrow.will you be joining the worcester gang in the air,,,,,, Quote Link to comment Share on other sites More sharing options...
wallboy Posted April 25, 2012 Author Share Posted April 25, 2012 looks good.were abouts in worcester are you.did you make your own prop,sean has a rad arrow.will you be joining the worcester gang in the air,,,,,, Im actually from Tenbury Wells but put Worcester as my location as not many people have heard of Tenbury My prop was from Thailand and I may have to pop over once the weather gets better and once ive got more than my current 4 hours air time under my belt. Quote Link to comment Share on other sites More sharing options...
pauldeakin Posted April 26, 2012 Share Posted April 26, 2012 Cage is a big improvement, but have you thought about about fitting some J bars or swinging arms, or would that mean having to buy a new harness? I guess that you can't 'weight shift' with your current setup Quote Link to comment Share on other sites More sharing options...
pauldeakin Posted April 26, 2012 Share Posted April 26, 2012 This reminds me of a debate that me and Pete got into when I mentioned that my old Rad was a pig to start when it only had a couple of litres in the tank. I concluded that the pump was limited as to how far up it could draw fuel, in that a full tank was easier for it, Pete disagread saying that such a carb could pull much higher. Now I would say it is not so much the height but the inertia of an excesive amount of fuel in the pipe/bulb that could be the problem causing running/starting problems. The idea being that the fuel "jumps to the attention of the suction pulses" when there isnt much but becomes more slugish to rapid movement when there is a lot of it. Nige or it could be that you had a weak suction pulse because these engines do not have a reed valve Quote Link to comment Share on other sites More sharing options...
wallboy Posted April 26, 2012 Author Share Posted April 26, 2012 Cage is a big improvement, but have you thought about about fitting some J bars or swinging arms, or would that mean having to buy a new harness? I guess that you can't 'weight shift' with your current setup Yeah I would have to buy a new harness if I got J bars fitted and that would end up costing me too much unfortunately and no im not able to weight shift with my current high hang points which hasnt really been a problem. Well, it kind of was on my very first flight as my arms were aching so I had to keep putting my hands down lol Quote Link to comment Share on other sites More sharing options...
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