I would like to know how many Guys are haveing bad vibration issues with these Engines. I have two of the 3W 55I's and one of the 3W80XI's and two DA50's and a DA 100's I am finding that the 3W's vibrate badly and the DA's are one heck of a lot smoother. I was out today with some guys with the same plane & engine combo's
We compared the plane engine combo's and found that a Da 50's will pull atleast 1,000 RPM higher with the same prop. We also flew the same plane eng. combo's, and found that the Da50's out preformed the 3W 55I's, which are a Lb.&1/4 heavier than the Da50's what a bumber!! We also found the same with the new 85's The DA's are very smooth and the 3W's vibrate the air frames badly. What to do? , What to do ?

I've had my 3W80XI for about 2 1/2 years. No one at my field has a DA 85 to compare to, but my 3W doesn't have excessive vibration.

Dan

I think you will find that most engine vibrations, are not really due to the engine, but an improperly balanced prop. The prop blade needs to be balanced first and then the hub. Blades first, then hub. Also, look at the spinner balance. I think this is the most over-look item and not done properly. Close-a-enough is really not good enough, closer to perfect is much better. Of course, this is only my theory.

I have recently bought a 3w80xi no excessive vibrations. Did you mount the engine directly (as you should) or do you use rubbers or vibration mounts?

Ronald.

I can not compare 50-85 cc engines as I have only da50 but I have experience with 4 different engines in 100cc class, namely bme110extreme, da100 new version, 3w106 classic and 3w106TOC. For smoothness first comes the bme (runs like an electric) than da and last 3w(I can say 3w really shakes essipecially near idle). For power 3w is consirably superior to both da and bme. 3wTOC>3wclassic>da~bme.

My 3Ws shake more till I get them dialed in and leaned out. I also balance the prop blades and hubs. This does help on any gasser.