skyfox1

Hi Nev no l haven't done fuel flow and l replaced fuel lines and suction line as far as l can tell all looks tight .

Fuel filter is glass type with cleanable mesh .no fuel pressure gauge or electric fuel pump but l did fit temporary fuel pump and no change to full power check carby float levels all with in specs .still scrathing my head i will find the problem .

Yes Tim thats what i recon but nothing l do makes any difference the thing that gets me is go flying on a cold day runs perfect runs good temps full power couldnt ask for perfect set up soon as the outside temps rise 5 to 8 degree wont get full power loose up to 800 rpms .

Hi Phil the motor is in pusher configuration in a Drifter sound like you have had great run out of your engine .

Hi Tim yes replace crank and new seals and all my engines l rebuild go though the proper rotax break in process. Plugs l use are br8es and oil is castrol 2t .

Hi Andy the swiches are one common thing l haven't checked l do a mag check and both work fine could be some intermittent problem will change them see what happens fuel tank breather is all clear replaced fuel pump as well fuel bowls are at correct level .and yes both engines have the same problem it must be some thing simple which l cant see l have swapped old parts back no change.

No offence taken Dazza got to have some fun .

Dazza wish they would have a duel might fix the problem .i will correct my spelling in the future.

Cheers Geoff

Hi Maj the engine that grab was an engine that i bought 2 years ago was running perfect did about 180 hrs then after about half an hour into flight lost power landed pulled engine apart found mag end piston had grab and scored the bore .i have rebuilt the engine myself which l have done many 503s before none have ever had this problem before will go back to the 50-1 mix see what difference is thanks for you input Maj

Its duel carby duel cdi with oval aircleaner which l changed for single k&N filters no difference. Have changed tachos to see if it was that but still no difference .also got a brolga three blade prop swap out the ivo three blade still no change .when l get it all sorted out hopefully soon l will try your warming process Yenn.

Hi Maj i had a one piston grab and since i have rebuilt the engine l have been run extra oil 50 mls per 20 lts fuel do you think that would make that much difference in the rpms on different temperature days.

Cheers Geoff

Carby boots all new

Dont have a problem with temps its just that yesterday in the hanger start the engine warm it up go full power get 7100 static cool day without touching or doing any thing start up following day same procedure warmer day only by 7 degree static full power 6000 rpms .

Hi Andy l had the problem after rebuild l pull motor apart and rechecked everything was right nothing changed so then i started renewing bits to try and elimanate the cause put new on then back to old still cant resolove it what ever is causing it has done the same on my spare engine even Wal at bertflood cant work it out.

Hi Tomo have a new muffler and have sync both carbs with a carby mate .

Hi Maj 1100 on both EGTs runs the best on cold days hot days loose 800rpms i have changed jetting makes no difference.

Hi Ralph i am using the k&n dual aircleaner and have changed muffler also sealed ports did a pressure test on case no leaks .i love 503s also in all the years l have used them never had this change in weather conditions.

Could some shed some light on my rotax 503 scratched my head some much l going to go bald .

l rebuilt my 503 some months ago since then when the weather temp changes so does my engine set it up for static 6200 rpm on the ground cold day about 10 to 15 degree day full power in flight 6800 .when the weather is about 20+ degrees can only get 6000 rpms .carbys set and jetted for sea level as l am only 150 above sea level put new carbys change cdi coils, new plugs ,new fuel pump air cleaner even changed stator .nothing makes any difference .if l change the prop pitch to get to the 6800 full power on clod day it gets to 7200 which is not good .

put your thinking caps on hopefully give an answer please.

Cheers Geoff.

I haven't riveted mine to the cross bars either doesn't need them to many areas for moisture to get in the chromoly tubes .

geoff

I have rivited mine Marty

Hi Marty just buy some lexan the brand I am using is Tuffak its 2mm thick and make the screen yourself its quite easy just make a template out of card board lot of put on trimming taking off till you get it right I only have front section of the screen don't have it on the top of the cabin .

cheers Geoff .

RIP Pud may your Thruster soar you though the heavens .

Hi JG3 centre the stick put straight edge on the bottom of the wing along the rib and adjust each aileron so the trailing edge just touches the straight edge and that will be set fine.

cheers Geoff.

Hi I am chasing 2 Eboxes (CDI coils ) can be from 582 for rotax 503 does any body have any for sale new or second hand must be working order .

cheers Geoff

Thankyou very much guys the pics are great help .

cheers Geoff