dead stick with katana v2 70 and 46

[rhk]

Have both the katana v2 70 and 46. Both engines would cut off after a few circuits. Unfortunately the katana 70 was totaled following a mid air collission ! I am currently using an OS 46 ax on the v2 46 , and the engine runs fine on the ground. In the air, it quits exiting a loop, everytime. I replaced the stock tank with a DuBro tank, with no change in the results. Is there a particular type of tank one needs to use or shortening the clunk tube length ? I also tried running the engine on the richer side.

Would appreciate any suggestions,

Thanks

[Edge 540]

Hi,
Sorry to hear about the midair. That's never fun. The 46AX is a great engine and a good motor for that plane. Without seeing the plane it's hard to tell but it sounds like you either have a tuning issue or a fuel system issue as you suspect. There's nothing about the design of the stock tank itself (when properly set up) that would cause your motor to quit. Afterall it's just a plastic container with a clunk! haha Make sure the fuel system is airtight, no pin hole leaks in the lines etc. Sometimes they can be very hard to find such as tiny holes near the connections at the carb or muffler. Replace all the lines inside and out and see if that helps. Other things to look at are the clunk and filter if you're using one. Any debris in there? If the engine is quitting with throttle changes that sounds like a needle issue.
Good luck!

[rhk]

Replaced all the tubing, and added a small header tank, thinking that it would solve the deadstick problem, only to experience another deadstick exiting a loop ! Currently using 5 % nitro, could that be an issue ?

[Thumbsticks]

One possible cause maybe the tank clunk tube is too long and hanging up on the aft end of the fuel tank. First, empty the tank of fuel and hold the airplane verticle with the nose high and shake the airframe...you should hear the clunk hitting the sides of the tank. You can shake it forward and back then right to left. As a second check, fill the tank full and gently turn the aircraft inverted and then see if you can totally drain fuel from the tank until empty..if the clunk is hanging up inverted there will be remaining fuel in the tank and you'll have found the answer to your problem. Hopefully you can find the problem on the ground and not keep risking the deadstick landings.

[rhk]

The tank drains fully, when inverted. Tried a uniflow system, which had disappointing results. The only time it did not deadstick is when I put the muffler baffle back in ! Did not expect the 46 ax to be so sensitive !

[Simpleton]

Do you have some foam isolating the tank from the airframe vibration? And also be sure the tank isn't mounted too "hard", like with zip ties, use rubber bands to further reduce vibration.

[rhk]

Tank is mounted with soft foam 1" on either side, and zip ties were replaced with rubberbands! So far flying with the baffle works.

Would I get more tank pressure with a tuned pipe or moussecan muffler ?

[pitviper51]

i seem to always end up with issues with nitro stuff.. once fix i found to work on my 90 os after new lines and plugs.. and tank.. still no fix, then i put a piece of fuel tube over the needle valve connection and the carb,, no air leaks now runs good till i run it to rich.. i guess being a glider pilot helps or the glider gods dont want me flying nitro planes haha.. but thats why i use gas planes now,, soo much more reliable
mike