3W275 Questions

[Galaxy 3D]

I am getting a 50% Yak 55 from Bill Hempel. The recommended engine is the 3W275. There is not much information out there on the engine (3Ws manual are to generic). I would like to get some feed back from 275 owners about the engine.

Thanks,
Tony

[Showtime]

I am with ya on this one brotha. i have one and installed it on a 50% edge. But i have not done anything else.
Does the carb need its own air. Should we run a filter on it so it does not spit and so on. any help would be great.

[snap a saurus]

Galaxy
In the manual, they call for 3/4 turn for high needle and 1 3/4 for low needle, that's wrong, it's actually the opposite.

[Chris Puckett]

Mine is easy to start and makes good power. Not real slow to break in but takes alot of gas. The only problem I have had with mine is my base gaskets blowing out. Other than that no issues at all.

[Galaxy 3D]

	Quote: Originally Posted by snap a saurus
	Galaxy In the manual, they call for 3/4 turn for high needle and 1 3/4 for low needle, that's wrong, it's actually the opposite.

Great to know!

[Galaxy 3D]

Another issue is really bothering me. In the manual it states the engine will not run properly unless there is an air scoop provided for the carburetor. Now I have looked at the build threads out there that use this engine and I have not seen one person have an air scoop. I am guessing it is not necessary?

[kevinf2501]

I have just installed one on my 50pct Hempel Yak. I will be adding a filter from AI as I heard the carb does like to spit some gas and I dont want it inside the plane

[kevinf2501]

Air filter

[snap a saurus]

	Quote: Originally Posted by kevinf2501
	I have just installed one on my 50pct Hempel Yak. I will be adding a filter from AI as I heard the carb does like to spit some gas and I dont want it inside the plane

I definitely recommend making a big hole below the carb even if you have the filter, the carb spits a lot gas during priming, even with the filter you will still get some.

[kevinf2501]

Thanks for the tip. I will definitely extend the hole further down as suggested

[toc pilot]

Hey, I have some great pictures of the mototr box area and what I did to modify it for the carburator and air-filter. Cut a BIG hole and have a clear area under the air-filter so the prime can drip out of the carb/filter to the ground. YES, you MUST have a filter to reduce spittage (IMO)! There is pleany of air for the engine and no scoop is required.

The 3W-275 is probabbly the best engine 3W makes, very powerful and very easy to maintain. Remeber to baffle the engine though... I have pictures of that too and I can post them later when I get home from work.

Bill Hempel

[kevinf2501]

Bill

Pics of the carb area and baffling will be very helpful as I am about at that point in the build.
I am waiting for my filter to arrive from AI.

Thanks
Kevin

[kevinf2501]

Bill

Pics of your baffling would be much appreciated. I have a couple of options for doing it however a picture is worth a thousand words.

Thanks
Kevin

[toc pilot]

	Quote: Originally Posted by kevinf2501
	Bill Pics of your baffling would be much appreciated. I have a couple of options for doing it however a picture is worth a thousand words. Thanks Kevin

Here are some pictures. Engine is the 3W-275. 1/8" balsawood makes up the baffle. The baffle slips over the engine and just simply sits there. There are provisions for the forward plug caps. The foam on the front of the baffle mates up with the front of the cowling and everything stays in plane. The bafflecan move a little bit as needed but it moves with the engine therefore it does not break due to vibrations... Pretty cool huh?

BIll

[kevinf2501]

Bill

Thanks! Very nice work. I will be making some baffles in the next week or so
Many thanks for the pics!!

Kevin