I have a Toro 25 on a Cap and a Ryobi 31 on a Stingray and they both run great on the ground. They idle great,
rev up and scream at full throttle. When I get them in the air all of a sudden they don't rev up , they sound like
they are running rich, I've played with the needles with no improvement. I flew they 31 again yesterday and it's
doing the same thing, after I landed and taxied over I stood with my legs against the elevator and it reved up fine,
any ideas?? thanks ...Craig

Craig,
I have had a Toro 25CC for going on three years. I had the same problem you did. I was told to solder a brass tube
on the other side of the Walbro Carb. (opposite side of the fuel in line) There is a small hole already there. Put a
piece of gas tubing on the new brass tube and put it back into your fuse. That worked for me. Also you can buy a
Velosity Stack for your Walbro Carb.

Louie, Louie

Louie,Louie, OK I'll try that, may be difficult with the Cap , it's very open into the fuse. The engine is mounted on a "box" that's
open into the fuse. Maybe I can close it up with some balsa or something. The stingray should be straight foward except it's
such a pain getting the motor out. Did anybody else have this experience ?

Craig,
About 75% of all the flyer's that I talked too had the same problem. Some fixed it by soldering the air vent I told you
about and others used the Velosity Stack. Some used both.
louie, louie

OK thank you, louie,louie, I don't think I'll get a stack on the Ryobi and I have one on the Toro so I guess I have to vent them
both

Do you think I'll have to play with the needles again, or will they be good where they are,
both engines are perfect on the ground....Craig

What the vent does is stabilize the air presure senced by the rear diaphram.
I have mine vented through the firewall and the Toro runs great.

I put mine on when I was doing the conversion so I can't say it helped.
But it does run extreamly good.
The small yellow line is the pulse line.
The blue line is the one were talking about.

I can't see where the blue line is going , but I'm guessing it goes to the plate that has a little hole in it? And then run
a line into the fuse where it's out of the wind? So if I tap this hole and put in a little nipple like on the 40 size mufflers
and stik a line on it and run it into the fuse I should be OK? Is that right? Craig

Yes

I used a larger nipple. Du-Bro Cataloge number 539.
It's 8-32 pressure fitting.

Smaller may work okay but I know this one works.

i just enlarged the little hole to a 1/8" hole then soldered a pc of 1/8" brass tube in.

OK thank you all very much, I'll try that and let you know what happens this weekend.....weather permitting!

There are a lot of things about California I don't like ....... But it was 74 degrees yesterday. [8D]

well I guess that's a little better than 28* with wind out of the north at 20 !!!

well I put in the vent tube into the fuse ,cleaned and gaped the plug, and changed the prop to a wood 18x6
had a MA 18x6 that was beat up. It's better but not what I think it should be. Next thing I'll change is the fuel,
I'm using what I stole out of my kids four wheeler and not 100% sure of the mix. What are you guys using for
props? and what rpm are you getting? Once this is runnig right the next project is SMOKE !!!