i just got the motor installed on my senior, but the fuel lines are touching the back of the crankcase just a little. will this burn thru the lines or should i isolate the fuel lines.?

SigMan, Your fuel line will be fine..

Except for one thing... Make sure they are just touching... They won't burn (they're silicon), but if it's touching the back of the crankcase just make sure the brass nipples from your tank aren't "pushing" into the side of the tubing. The extra vibration from the engine could cause it to chew right through the line if it is. Should be fine as long as the brass isn't any closer than 3/8" or so from the crankcase...

thanks guys... cant wait til the wheather cooperates to fly this bird.

its AOK if it is touching, but the other thing to look for is how far it goes into the back of the crankcase. That is, could the hose be slightly pinched coming around the back. If that happens you might not get good fuel delivery.

Actually I think an install without the hose touching the motor at some place would be just about impossible.

Just touching is not OK. No, it won't burn or melt. It will wear away from the vibration and a hole will eventually appear. It may take as long as a year to happen. It is one of those things you might choose to live with, but keep an eye on it.

mine touches in my sukhio, so yours should be fine. Do keep an eye on it though.

just get a couple of (zip) cable ties and wrap it around the line.
Not tight, but just snugg enough. Let the cable tie head rest against the engine.
this will create space between the line and engine.
This will also prevent heat transfer from the engine to the line.
I do this on my nitro cars/trucks
Engines perform better on cooler fuel.