RE: 3W 75
 

The 3W60, 3W70 and 3W75 all use the same Owners Manual. You can get it off of 3W's website or you can PM me and I will send you a PDF of it. The manual says 98 octane is ideal for all three motors.

The recommended props for the 3W75 are as follows and the book recommends 1 turn out on both the high and low speed needles.

2 Blade
24x10; 26x8; 26x10;
26x12

3 Blade
22x12,23x12 24x12

My 3W60 has a 24x8 on it and it works fine.

RE: 3W 75
 

Bear in mind the manual states octane using the European means of measurement, not U.S. For the U.S., use premium grade gas and you'll be where it needs to be. Higher compression engines require higher octane fuels. There's no getting around that. 3w is an engine line developed around higher compression ratios. BME, ZDZ, some DA, and MVVS/Evolution, are also higher compression engines and should not be subjected to regular or mid grade octane levels.

RE: 3W 75
 

Hi,

In my research fleet which logs a bit of time and works very hard pulling draggy samplers, 91 octane, US is the premium grade which gives the best performance. RPM improvements are 200-500 over 87 octane. This is true for 3w engines from the 24 cc size to the 212 cc 4 cylinders. I either have or had most of the sizes manufactured by 3W up to the 200 cc twin or the 212 4 cylinder. I had several 75 cc single for a while (both the rear and side carb models) It is a great engine and definitely needs 91 octane fuel.


Elson

RE: 3W 75
 

HRRCFLYR, I GOT OF GOOD INFORMATION FROM A LOT OF GUYS, BUT WAS HOPING TO GET SOME RPM INFORMATION. THE SMALLEST RECOMENDED PROP IS 24/10. THIS IS WHAT I AM USING AND I EXPECTED TO SEE OVER 7000 RPM HOWEVER IM GETTING LESS THAN 6000. AS STATED EARLIER THE CARB HAS BEEN REBUILT INCLUDING NEW REED.SHOULD I BE LOOKING FOR ANOTHER PROBLEM(IGNITION) OR IS IT IN THE NORMAL RANGE AND CANT EXPECT MORE. THANKS, JIM

RE: 3W 75
 

http://www.flyin
ggiants.com/forums/showthread.php?t=1298


put the above line together and pate to a browser

RE: 3W 75
 

My manual states 24 X 10, 26 X 8, 26 X 10, 26 X 12 and RPM from 1100 - 8500. IMO, take a look at leaning out the oil mix to 1-80 mix of full synthetic (recommended in the manual), and lean out your top for best high end less 200RPM.

RE: 3W 75
 

Bipeflr,

Give Gerhard at Aircraft International a call. He knows more about 3W engines than I ever will and he is a great guy to talk to. Explain to him what you have and ask him why your RPM's are so low. FYI, the phone number for Aircraft International is 1-732-761-0997. If you want to send him an email, his email address is gerhard@aircraftinternational .com.

David

RE: 3W 75
 

THANKS, JIM

RE: 3W 75
 

Speaking of 3w dealers, I'm hearing rumors that Cactus Aviation has been sold. No verification on that yet.

RE: 3W 75
 

From their web site:

Cactus Aviation has new owners and a new address!

Same phone number 520-721-0087

Cactus Aviation
8020 S. Farmview Pl.
Tucson, Az. 85756