snappa

Just some info, I was flying my caliber today and when I came close in a hover I noticed the header tank was half empty but the main was half full.....duhh that bad ...very bad came down and checked it out....what I found was the tube for the clunk had come right off!! this was where the fuel enters the main tank,,,with a strip down the clunk tube was totally perished and had fallen apart!! all the other tube is my tube but the clunk is koyosho...if you own a caliber it might pay to check this....anyone know why it failed?? I empty my tanks after each session

BarracudaHockey

My Feedback: (11)

The clunk lines supplied with most of the kits today is junk. It doesn't hold up well, and the higher the nitro you run the worse the situation is. Lean runs due to collapse is the first sign and inconsistent mixture after 1/2 tank is burned.

Replace it with Hayes black clunk line, cut it a little short of what you think you'll need and replace it yearly. Its not just the Cali, all the Kyoshos and the Raptors and Shuttles are known for this issue.

http://www.ronlund.com/Merchant2/mer...ct_Code=HAY249

polygoo

i'm confused, when you say "clunk" lines, do you mean fuel lines?

Also, what is aheader tank for? I only have one fuel tank, a fuel filter inline to my carb, and another tube going to the tank from the exhaust pipe.

Thanks

BarracudaHockey

My Feedback: (11)

Clunk lines go from the fuel tank stopper to the bottom of the tank where they are attached to a metal weight, called a clunk. Hence clunk line. They are subjected to muffler pressure and constant immersion in nitro and they tend to wear faster than the rest of the line. The best thing is to replace the clunk line when you build the heli and every year or beginning of the season thereafter. The higher nitro fuels will deteriorate the clunk lines more quickly.

A header tank is a bubble trap and is designed to give your engine a constant mixture whether upright or inverted regardless of the level in the main. They are nice if your flopping around, when your learning you don't really need one. Some people use them to get longer flight times as well, I land once the main is empty.

W H Bonney

We spend the bucks on a new heli and they send us junk fuel line. I had a Venture 30 fun heli BTY the line was spent right away, so was the rubber mounts on the skids.