Hi Anurag

I am sure you have a leak from the UAT somewhere which is exaggerated by the suction of your thirsty engine. It's either coming from one or both of the nipples or the cap.

When I built a Olympus powered Ultra Bandit a couple of years ago I looked at the tank setup and decided to change it. I didn't think the hole in the hopper tank to UAT fitting was big enough and neither was the nipple on the UAT. What I did was fit 4mm ID nipples to the UAT along with a 4mm ID cap fitting. I drilled the hopper tank fitting out to take a 4mm ID fitting too and also made a clunk with again with a 4mm ID. This way I had 4mm ID all the way from the clunk in the hopper to the pump and the UAT never sucked in at all even when the Oly was at full power.

As it happens I am just putting a Airworld F-100 together and I am doing the same thing for the UAT and here's the pic. The pic shows the two 4mm ID nipples next to a standard size one and a 4mm ID cap fitting.



Jason