Does anyone have first hand knowledge on the "difference" between the 3W-75i/rear carb and the 3W-75iUS/side carb?? It looks like performance should be the same? Rear carb is heavier by a little. Rear carb looks like it would be harder to mount? and the side carb would need a wider Cowl?

I guess I was wondering about starting, running, fine tuning, etc. Really any difference?


thanks, Ward

Hi,

I have had both models and they both run the same. They are both great engines

Elson

Rear carb engines are not more difficult to mount, just different. There are actually several advantages. One of which is that you can adjust the carb while the engine is running.

Both engines run about the same.

Safe Flying!

I asked someone in the 3W circle once why these two very similar engines are offered by 3W instead of just going to one. I was told that the warbird flyers bought mostly "i" versions because they fit well in those type cowlings and the sidecarb version was prefered by everyone else because of lighter weight. That person said it makes economic sense for 3w to continue producing two type 75cc engines to service the two markets. I think this is the idea behind the intro of the 55cc sidecarb engine, lighter weight, to better compete in the 50cc class of aerobatic engines istead of just the 50i engine that everyone knows is at least a full pound heavier than DA, brison, bme and others.

Thanks for the input guys, very helpful information. I believe what I'll do is measure the width of the Cowl and make sure the side carb will fit. I like the idea of 4.75 lbs vs 5.2 lbs.

Ward

get the 80xi, 5.05 lbs, little more power, and 600.00 right now

I have one and it's a nice engine but I have to tell you it's the biggest pain to mount right. All rear carb engines require a hole in the firewall but the 80xi requires a hole that puts it so close to the mounting holes even using the 3W plate that you have to grind off the side of the standoffs to clear it. That and the carb block, carb, and velocity stack stick way back there - you have to make room for it.

I guess i didn't have that problem with mine, on a 33% hangar9 sukhoi. It mounted right up, no hassles, no surprises. anyway, I was just throwing out an option in the same weight range, slightly more power, and a LOT less money. that money saved was way worth sinking my carb into the motor box

Ward, you'll be happy with the 3W, no matter which direction you go. Enjoy, and let us know how your project comes along!

Chad

I can endorse the 75ius as well It puts out Great Power , but this is a "Overlapping" endorsement as I bought this one from Elson who posted earlier !! I have mine mounted on a Lanier Edge 540 30%

Hi, I just got a side carburator 3w75i, and I want to mount this engine in a yak 54 Lanier, how you 540 30% took this engine, is your airplane too heavy for 3D what was the final wt of the plane. thanks. for you imput in advance.