stihl 028 super leaning out

[huskihl]

Have you seen what most carb cleaners do to black rubber?

A lot less than running the saw lean will do to the piston.
He's spraying some here and there to find an air leak, not soaking it for a year

 

[Chainsaw Jim]

A lot less than running the saw lean will do to the piston.
He's spraying some here and there to find an air leak, not soaking it for a year

I'm talking about how it will crack rubber on contact. It's quite disappointing when you wipe a spot clean with a wet q-tip then bend the rubber piece and it immediately splits in two.
It also damages other plastics and paint.

I would have pm'd you if I was arguing your point. I said what I said because it's important information regarding use of carb cleaner while a carb is still on a saw.

 

[huskihl]

I'm talking about how it will crack rubber on contact. It's quite disappointing when you wipe a spot clean with a wet q-tip then bend the rubber piece and it immediately splits in two.
It also damages other plastics and paint.

I would have pm'd you if I was arguing your point. I said what I said because it's important information regarding use of carb cleaner while a carb is still on a saw.

No I haven't noticed that. I've cleaned lots of things with it and the only drawback I've seen is it dries too fast in some instances. I have seen trichlorethane (what some electric motor and brake cleaner is made of) completely disintegrate some plastics on contact.
And yes, if it's not original paint or powder coat it can be hard on paint.
I guess when I'm checking for a leak, just a tiny amount around the carb evaporates before I've seen it do any damage to anything. Older or other plastic parts may be different though

 

[Wood Doctor]

Well i put a carb i knew was good on it and that seemed to fix the problem . So I'll probably just get a new carb for it . I sprayed a little carb cleaner around the throttle shaft and it died instantly. Those chinese ones are pretty cheap so I'm not gonna mess around long on this one .

This always fascinates me with 028's. I swapped carbs with two 028 Supers and then both ran correctly. One hated one of the carbs and the other didn't care which carb was installed. Things like this drive you wacko.

 

[Crzybowhntr]

If not the vent check the impulse hose , manifold (cracks) as well as the carb diaphragms and screen are'nt dried out or plugged with sawdust .
Beyond those I would be suspect of a seal / leak causing it to lean out .

I vote this. Both my 028 super and my 038 Mag II had impulse and carb boot cracks that caused them to run as you are describing yours is

 

[kkemp]

This always fascinates me with 028's. I swapped carbs with two 028 Supers and then both ran correctly. One hated one of the carbs and the other didn't care which carb was installed. Things like this drive you wacko.

Yea that's crazy . Lol .

 

[kkemp]

It's running good now . Holds steady at about 12600 rpms . I had put a new tank vent on and tonight I was cutting and it leaned out bad again .. put a different vent on and now it's running good. With the base gasket delete and some light porting this thing is a beast .

 

[Duane(Pa)]

It's running good now . Holds steady at about 12600 rpms . I had put a new tank vent on and tonight I was cutting and it leaned out bad again .. put a different vent on and now it's running good. With the base gasket delete and some light porting this thing is a beast .

Are you running modular tank vents or the fuel hose/screw gizzmo?

 

[kkemp]

It's the fuel line with screws . That's what was on it .

 

[Duane(Pa)]

It's the fuel line with screws . That's what was on it .

Ok, Mine too. I found out that when you put the screws in, you have to shove them, don't twist them...they will cut threads into the hose and seal too tight to let air get past...

 

[kkemp]

Ok, Mine too. I found out that when you put the screws in, you have to shove them, don't twist them...they will cut threads into the hose and seal too tight to let air get past...

I don't remember if I turned them in or pushed . I had made it a while ago .

 

[Wood Doctor]

It's the fuel line with screws . That's what was on it .

That's how I run all my 028 Supers. Fuel line with #6 machine screws. I make my own tank vents. They work.

 

[MustangMike]

Pics? I got some addl AM tank vents when I did the 029, seem to have a little filter on the end. I think the next time I need one on an 044 I'm gonna give one of them a try.

 

[huskihl]

Pics? I got some addl AM tank vents when I did the 029, seem to have a little filter on the end. I think the next time I need one on an 044 I'm gonna give one of them a try.

It's a nipple sticking out of the tank, a 2-3" fuel hose, and a grub screw pushed in

 

[MustangMike]

Thanks, but I was referring to what Wood Doc is describing.

 

[Nitehawk55]

Echo has a great duckbill type vent assy in a small plastic type that fits right on a hose including the 028 .
Part # is A356000030

 

[Wood Doctor]

Ok, Mine too. I found out that when you put the screws in, you have to shove them, don't twist them...they will cut threads into the hose and seal too tight to let air get past...

I often thought that but recently I saw one of my shop-made vents on an o28 Super working just fine. The 3/8" #6 machine screw was letting fuel escape just fine. I had left the cap on and set it in on the top by screwing it into Tygon fuel line. Little bubbles were going right to the top.