Is it a good practice to put some rubber (such as bike tire) between the engine mount and the profile body in order to reduce 4 stroke vibrations ?

thanks

i have always just hard mounted mine on those hardwood rails. the main thing is usually 3-5 degress of right thrust is neeeded on those 2 front engine bolts if you are the type who gets into trimming a bird for the correct right thrust to have smoother uplines and things of that nature.. With you low end leaned to the correct spot the 4 stroke is not going to take your plane apart unless the motor is way out of ajustment and the plane is lacking in the glue/ca department....

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Same here, I just bolt it directly to the fuse. With a washer or two under the front bolts for a little right thrust. The rubber mounting sounds good, but the engine would start to be really far off the center line. Making it really heavy one the right wing.

I go flat to the hardwood rail. If the right rudder is getting to me, I'll add the washers, but I like to start off flat. I think the rubber thing wouldn't help as much as one might think.

On some of my profiles, the transition makes the fuselage flex a lot due to vibration, but I've not had a failure.

I will avoid using the rubber but speaking about right thrust it seems that when i drilled the holes for the engine mount i created a bit of an up thrust.
cause there is no replaceable engine mount it seems i have to live with it.
- is it going to be noticeable ?
- can i do something to minimize the up thrust effect ?

thnaks

You can take a tooth pick or somthing and epoxy it in the holes. After it's cured just cut off the ends and you can drill new holes. That's worked great for me.

Jason

Thanks for the tip on the washers and right thrust. This really helped me trim mine out!