I have a thought. To all of us who have had v-max engine trouble. I would like to know if you have had engine trouble what kind of fuel have you used during this trouble. Not just hard to tune v-6's but breaking rod v-7's as well. I would like to see if there is a common denominator..I am not trying to say that there may be a bad fuel source but maybe just the wrong kind for the finiky norvel.. Thanx for inputs.. Alan

I broke a rod while breaking in my V-max7. That was using Norvel 15% fuel with some 4 or 5 washers under the head.

My problem, at least, was not fuel related. The wrist pin had walked out of the piston and lodged in one of the cylinder transfer ports. The engine instantly stopped, of course, and snapped the conrod. It is my understanding that this was the usual source of broken rods for the Vmax7.

As far as fuels go I have run a wide variety of brands and nitro content. I have always found the engine runs better using higher nitro and richer needle settings. It seems you have to run rich no matter what you do, but if I run 10-15%, it has hard to get enough power running that rich. I usually run 30% and this allows me to run the needle safely rich while still having plenty of power. The motor stays nice and cool and is easily hand holdable after flying.

For what it is worth,
Spiro

Thanx this makes sence. I was running 15% and you are right I had to run a little lean to get power I think this is why I burned out my first 2 v-6's my v-7 broke the rod but I did not take the cylinder off to see why. When I first got my 110 I was running norvel 25% fuel and had NO trouble. The cost of the fuel made me buy the 15% omega. I have since stocked up on norvel again so I am ready when my new v-7 gets here.. Alan