Macsw Posted August 15, 2011 Report Share Posted August 15, 2011 The other night while taking off, I accelerated and the engine bogged down. Slow throttle to full was ok, faster caused the bog. I replaced the fuel pump, all lines and the filter. I checked the needle adjustment and the fuel mixture. All where they should be. I blew out the carb ports. Filtered all my fuel. I learned that if I had the filter installed the bog would happen. If not installed, it excelled OK. I cleaned the filter, but it still bogged. Without the filter, I noticed a spray mist of fuel when I excelled coming from where the filter attaches. I put my hand by the opening and it was sprayed with fuel when if did the excel. With the filter on, it acts like it is flooding...I am loosing some good flying weather here in Wisconsin and need to get back into the air...HELP! macsw@hotmail.com Link to comment Share on other sites More sharing options...
Tad Olmsted Posted August 15, 2011 Report Share Posted August 15, 2011 couple of questions: 1 last carb, fuel pump OH 2 What are you using for a pulse line 3 are you running a silencer or K&N filters 4 are you running an oil injector or pre-mixing fuel 5 are you running dual or single carbs The carbs will flutter or stumble a bit if the throttle is opened very quickly. This will happen in the 912 as well. If you have a short throw on your throttle linkage, you may be opening the throttle too fast. Sounds like it works fine when you go slow. To know for sure you will need to record your EGT's when this occurs. If you have a fuel starvation problem it will show up in your EGT indication. My bet is your pulse line is collapsing and/or you are running an oil injector that is not working properly. I'll be around the computer all day today and keep an eye out for you to see if there is anything we can do to get you back catching wind. Link to comment Share on other sites More sharing options...
Macsw Posted August 15, 2011 Author Report Share Posted August 15, 2011 Replaced fuel pump. Current Carb has 50 hours. Is a Bing 54. Is a single carb with no silencer or oil injector. I pre mix. Pulse line also less than 50 hrs. Cleaned my K&N filter, still no results. Question, is it normal to get fuel spraying out of the carb inlet when the Air filter is not installed upon initial throttle? have been using the throttle opening speed since I got it without this problem occurring. Seems like it is flooding when I excel hard. I tested this by applying some primer when it bogs, just makes it worst and dies, so not a fuel starvation problem couple of questions: 1 last carb, fuel pump OH 2 What are you using for a pulse line 3 are you running a silencer or K&N filters 4 are you running an oil injector or pre-mixing fuel 5 are you running dual or single carbs The carbs will flutter or stumble a bit if the throttle is opened very quickly. This will happen in the 912 as well. If you have a short throw on your throttle linkage, you may be opening the throttle too fast. Sounds like it works fine when you go slow. To know for sure you will need to record your EGT's when this occurs. If you have a fuel starvation problem it will show up in your EGT indication. My bet is your pulse line is collapsing and/or you are running an oil injector that is not working properly. I'll be around the computer all day today and keep an eye out for you to see if there is anything we can do to get you back catching wind. Link to comment Share on other sites More sharing options...
Macsw Posted August 15, 2011 Author Report Share Posted August 15, 2011 Replaced fuel pump. Current Carb has 50 hours. Is a Bing 54. Is a single carb with no silencer or oil injector. I pre mix. Pulse line also less than 50 hrs. Cleaned my K&N filter, still no results. Question, is it normal to get fuel spraying out of the carb inlet when the Air filter is not installed upon initial throttle? have been using the throttle opening speed since I got it without this problem occurring. Seems like it is flooding when I excel hard. I tested this by applying some primer when it bogs, just makes it worst and dies, so not a fuel starvation problem By the way EGT and CHT are all normal and runs great except for initial hard throttle. Link to comment Share on other sites More sharing options...
Tad Olmsted Posted August 15, 2011 Report Share Posted August 15, 2011 I would tear the carb apart and double check all the jet sizes and make sure the clip position is correct. Sounds like you are getting way too much fuel. Also check the viton needle and make sure there is not a ring (or groove) where it meets the seat. Glad to hear you are pre-mixing. Also glad to hear you are at least getting enough fuel. Rules out alot of headaches. Link to comment Share on other sites More sharing options...
Tad Olmsted Posted August 15, 2011 Report Share Posted August 15, 2011 By the way EGT and CHT are all normal and runs great except for initial hard throttle. Good, that too rules out a lot of headaches Link to comment Share on other sites More sharing options...
Macsw Posted August 15, 2011 Author Report Share Posted August 15, 2011 Also took the carb apart and blew out the ports. Checked the needle position and o ring all where it should be. I am getting really stumped here Link to comment Share on other sites More sharing options...
Macsw Posted August 15, 2011 Author Report Share Posted August 15, 2011 Took out the mixture screw and blew out that port. Adjustment had not changed. Re adjusted. Link to comment Share on other sites More sharing options...
Tad Olmsted Posted August 15, 2011 Report Share Posted August 15, 2011 Get in the manual and make sure the jet sizes are correct for your configuration Link to comment Share on other sites More sharing options...
Macsw Posted August 15, 2011 Author Report Share Posted August 15, 2011 Sorry, did that too. Is it normal to have your hand sprayed with fuel mist by the filter opening when you excel. I am guessing that with the filter on, the mist is causing flooding, but why? Link to comment Share on other sites More sharing options...
Roger Lee Posted August 15, 2011 Report Share Posted August 15, 2011 Almost sounds like you have an air leak. Link to comment Share on other sites More sharing options...
Tad Olmsted Posted August 15, 2011 Report Share Posted August 15, 2011 Weird, I would have to be there. Sounds goofy, something is off. Link to comment Share on other sites More sharing options...
Macsw Posted August 15, 2011 Author Report Share Posted August 15, 2011 You know one thing I was thinking about is why the initial fuel mist exits instead of enters the engine? Do you think maybe an intake gasket leak? Link to comment Share on other sites More sharing options...
Tad Olmsted Posted August 15, 2011 Report Share Posted August 15, 2011 it would idle very high, but something is off Being a single carb, it may be that you are just throwing the throttle too fast and gagging the engine. It might not be able to catch its breath Link to comment Share on other sites More sharing options...
Macsw Posted August 15, 2011 Author Report Share Posted August 15, 2011 I will keep searching, but will let you know when I find the problem. Thanks for the tips.....Dan Link to comment Share on other sites More sharing options...
flyerme Posted April 6, 2012 Report Share Posted April 6, 2012 Pleas HELP.I have the same problem only my plane bogged also at criuse 5400revs and had to go full throttle to clear it .. problem..bogging when fast full throttle applied also slight bog down low. I flew anyway and after 15 mins in cruise she bogged and I had to apply full power to get back home..I have tried everything :- replaced carbie(bing 54) replaced fuel system,replaced exhaust,replaced complete engine,replaced gear box and prop,replaced engine mounts,removed all wiring,put a seperate fuel tank gravity fed into carb Still No change, just packed whole plane plus all x3 447's and drove 11 hours to specialist and still no change? maybe they just run shit?at 2500revs its rough and boggy,at 3000rev smooth but when hold cruise revs ,say around 5000rpm the revs move up and down?its only done 47 hour... I have 3 rotax447's all doing the same thing? any way did you sort it out? Iv been grounded for 3 months now very itchy to get flying... take it easy Link to comment Share on other sites More sharing options...
Jim Posted April 6, 2012 Report Share Posted April 6, 2012 Pleas HELP.I have the same problem only my plane bogged also at criuse 5400revs and had to go full throttle to clear it .. problem..bogging when fast full throttle applied also slight bog down low. I flew anyway and after 15 mins in cruise she bogged and I had to apply full power to get back home..I have tried everything :- replaced carbie(bing 54) replaced fuel system,replaced exhaust,replaced complete engine,replaced gear box and prop,replaced engine mounts,removed all wiring,put a seperate fuel tank gravity fed into carb Still No change, just packed whole plane plus all x3 447's and drove 11 hours to specialist and still no change? maybe they just run shit?at 2500revs its rough and boggy,at 3000rev smooth but when hold cruise revs ,say around 5000rpm the revs move up and down?its only done 47 hour... I have 3 rotax447's all doing the same thing? any way did you sort it out? Iv been grounded for 3 months now very itchy to get flying... take it easy There's not much expertise here on the 2-stroke Rotax engines. You might want to try here: http://www.homebuiltairplanes.com/forums/2-stroke-aircaft-engines/ Link to comment Share on other sites More sharing options...
flyerme Posted April 6, 2012 Report Share Posted April 6, 2012 There's not much expertise here on the 2-stroke Rotax engines. You might want to try here: http://www.homebuiltairplanes.com/forums/2-stroke-aircaft-engines/ thanks Link to comment Share on other sites More sharing options...
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