3W 75
 

I JUST BOUGHT A USED 3W 75 AND AM CURIOUS AS TO WHAT RPM I MIGHT EXPECT RUNNING A 24/10 XOAR BEECH PROP. JUST GENERAL RANGE (EAST COAST) Thanks for your reply in advance. Jim

RE: 3W 75
 

P.S. ITS A SIDE CARB OLDER VERSION......THANKS AGAIN JIM

RE: 3W 75
 

My 3w75 runs 6800 with a 3 blade mejzlik 22x10. A little hard to start first time of the day. Doesn't seem to be a power house.[sm=disappointed.gif]

RE: 3W 75
 

THANKS,....I THOUGHT THE 3W WAS SUPPOSED TO BE THE BIG BOY IN THESE ENGINES BUT I GUESS ITS JUST THE HEAVYWEIGHT. JIM

RE: 3W 75
 

When I bought mine from a friend he said 17 flips with the choke on, 7 after with the choke off for the first start of the day. He exactly right! Do this and it's 5 flips, then 3 for the first start, one flip stars the rest of the day.


Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.

After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.

RE: 3W 75
 

Not a power house? Is that related to RPM count or the amount of weight it can haul straight up?

RE: 3W 75
 

It is in a Ziroli P40 94inch 34lbs All it has to do is go fast and turn left (or right ) depends on wind. Seems to run out of juoce on upline.

RE: 3W 75
 

SOARRICH, THANKS FOR CHOKE SUGGESTION ILL TRY IT SINCE MINE IS VERY HARD TO START...I PRIMED THE CARB TO GET IT STARTED THE FIRST TIME.. JIM

RE: 3W 75
 

Try a different prop. Brand and pitch.

RE: 3W 75
 

Hi,

What octane gas and what oil mix? 3Ws put out more power with premium gas and richer oil content for better ring seal. The difference between 87 octane and 91 octane is sometime 500 rpms.

Elson

RE: 3W 75
 

WOW, I didn't know that. Am I hurting mine by running 87 octane? I run 87 octane and 32:1 aircooled in all my engines, would I be better off with the 91 octane in the others as well? 80 zdz, 85DA, DL50, MT 42,50,57,62 a bunch of 26cc's.

RE: 3W 75
 

i know the DA 85 and ZDZ require premium gas per their manual because of having higher compression

RE: 3W 75
 

IM USING 93 OCTANE WITH 7oz. SYNTHETIC 2 STROKE RACING OIL PER 2gal. OF GAS. I HAVE PLENTY OF POWER FOR A 20lb. KATANA BUT THE ENG. RUNS ERATIC,SOLID ON GROUND BUT STUMBLES WHEN THROTLE IS ADVANCED(sounds rich) I RAN A LINE FROM CARB VENT INTO FUSE BUT NO HELP. WITH THE ENGINE IDELING FUEL CAN BE SEEN DRIPPING...THE CARB HAS A COMPLETE REBUILD....I THINK THE CHOKE PLATE IS SIPHONING THE FUEL OUT SINCE IT IS IN THE AIRSTREAM..SINCE I AM AFRAID TO ADJUST THE CARB WITH THE ENGINE RUNNING I WAS TRYING TO GET A HIGH SPEED RPM SETTING OR CLOSE. IM TURNING 5900 WITH THE 24\10 XOAR AND WAS WONDERING IF I SHOULD CONTINUE LEANING IT OUT 1/8 TURN AT A TIME OR IF I HAVE REACHED ITS LIMIT....I GUESS IM TRYING TO CHEAT (70 years old and back just wont take it) BY THE TIME I GET IT STARTED,SHUT IT DOWN A COUPLE OF TIMES AND RESTART IM DONE FOR.......THANKS FOR THE HELP AND NO IM NOT GOING ELECTRIC.....old dogs........THANKS AGAIN, JIM

RE: 3W 75
 

Try putting fuel tubing about a foot long on the needle, it will still turn the needles and you are safe. Put something on the plane to keep the carb out of the slipstream or you will never get it to tune correctly.

RE: 3W 75
 

It looks like it's 91 octane for me from now on. Fortunately the DA85 is still a couple of weeks from flying yet, the ZDZ is a couple of months away from flying.

RE: 3W 75
 

turn the high at about a screw driver blade each time and restart and tach, this will allow you to keep all parts of the body safe and in a few minutes your motor will be tuned on the high needle. From there go to the low and do the same looking for a clean transistion from low to high. In the end you may have to do one more tweek on the high once you get the low adjusted. in the end life will be good

RE: 3W 75
 

I'd like to add that, if it is used and you don't know how much time is on it, you may want to check the reed valves behind the carb. Over time, they become frayed and worn and no longer seal tight. This causes some starting and transition issues, although high end loss isn't as noticeable. I get replacements from Aircraft International right there on the east coast. Gerhard is nice to deal with from my experience. He really knows these engines.

The tip on the choke plate is right on. Also, if when flying you notice it popping when changing attitudes like in a roll, just lean it out another 1/16 turn, till it runs smooth through any maneuver. I think mine is set with low at just under 7/8 turn, and high at just under 1 turn.

I have it in a 33% Godfry Laser. It is unlimited. The plane is almost 20 years old, but the 3W has only been in it for a couple years. It is the 3rd engine for the plane.

RE: 3W 75
 

I have a 3w 100 ? and wondering if it should be 98 octane or not . 8 /


I looked on 3w sight couldn't find a manual , and i really didnt know that they call for higher octane actuly I got told club mebmers at my field it would make it run lean and hot
I also don't know what model number the motor is I guess I can take the cowl off and find some markings in there

so my question is do all 3W's run 98 octane ? and 32 to 1 pens oil " yellow bottel lawnmower store brand

RE: 3W 75
 

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

Are you tempted to buy a high octane gasoline for your motor because you want to improve its performance? In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your motor perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual.

The only time you might need to switch to a higher octane level is if your engine knocks when you use the recommended fuel.

RE: 3W 75
 

THANKS TO ALL THAT RESPONDED,I WILL MODIFY THE CHOKE PLATE AS ADVISED AND ADD FUEL LINE TO THE NEEDELS AND I HAVE A 3W CARB MANIFOLD THAT I WILL INSTALL TO TRY AND CALM IT DOWN. ...... DOES ANYONE KNOW OF A LIGHTWEIGHT REPLACEMENT MUFFLER FOR THE 75 ? THE FACTORY WRAPAROUND IS HEAVYDUTY AND JUST HEAVY. MY KATANA IS DEFINETLY NOSE HEAVY AND AT 1200sq. in. AND 20 LBS. I DONT WANT TO ADD WEIGHT AND MY BATTERY PACKS ARE BEHIND THE TRAILING EDGE THERE ARE NO LOCAL HOBBY SHOPS IN MY AREA AND THE CLOSEST ONES WOULD NEVER HAVE ANYTHING LIKE THAT ANYWAY. IT WILL BE A WEEK AT LEAST UNTIL I TRY AGAIN ...LET YOU KNOW HOW IT TURNS OUT. THANKS, JIM

RE: 3W 75
 

The manual for my DA85 states: "Low octane pump gasoline is recommended. Higher octane gasoline can actually lower
performance unless a tuned exhaust system is used."

Has there been an update from DA about the recommended level of octane for the DA85?

-Ed B.

RE: 3W 75
 

so its unclean

3W100 calls for 98 octane ? yes or no ?
:(

RE: 3W 75
 

Flyfast1
u r correct in that the manual says to use low octane, however, DA says you need to use premium. I have one of their 85 and 2 of their 60. The 60 does state to use 91 or higher. I think the change to Da came after some issues arouse. Here is their number if you need to ring them DA = 520-772-0607.

732-761-0997 Gerhart can give you the correct scoop on your 3w brand of motor zacharyR

RE: 3W 75
 

From my 3W manual:
"Use a high Octane fuel (98 Octane is ideal)"
"high grade 2-stroke oil............Pennzoil 50-1, Redline 40-1, Amsoil DOMINATOR 50-1, Amsoil Saber 100-1"

RE: 3W 75
 

sounds like avation gas i think that stuff is 100