034 Super Tank vent

[Honest John]

Can somebody please edumacate me on these tank vents ? The saw is a 034 Super that had been sitting for 10 years or so. The fuel line crumbled, so that got replaced, but the saw is still not drawing fuel. I cleaned carb pretty thoroughly with brake cleaner and then blew it dry with compressed air but the saw is still not drawing fuel. I'm convinced it may be this tank vent.

The tank vent has a forward facing screw, and then on the underside it has a very small screw on the inside. I did a google search on this and can't find a whole lot of info on this type of vent. I want to be able to clean it and ensure it's working properly.

BTW, this isn't my pic, just one I stole from google, but it's the same vent.

Thoughts ??

 

[5000+]

The tank vent will not cause your no start. It can make your saw starve for fuel after it runs for awhile. The vents job is to let air in to replace the fuel being used. It prevents a vacuum from occurring in the fuel tank. I believe your style vent let's air by the threads of the screw.

 

[huskihl]

Usually they'll start even with a bad tank vent. I think the vent has a passage in it that let's air through. Those screws are supposed to allow air to seep by but not fuel.

Did you put new diaphragms in the carb? Old ones get hard and don't flex smoothly. They're what pumps fuel in to the saw. And also check the impulse line for cracks.

Also , make sure the choke closes all the way

 

[5000+]

Did you pull the carb apart and clean it and put in a new kit. I would replace the impulse hose and fuel filter. You can try to get it to run by putting a little mix down the carb bore.

 

[Keith Gandy]

Is the plug getting fuel? Could be bottomend seals r bad or needs carb/kit, fuel lines good? That tank vent operates on a grub screw. Just unscrew and make sure passage is clean

 

[Keith Gandy]

Pour alil mix through plug hole and try to start see if she fires

 

[Keith Gandy]

Put a gauge on the impulse line and pull starter over to see if needle fluctuates back and forth. Just several ideas to look at

 

[Honest John]

All good thoughts....

Plug is not getting fuel and it fires when you pour mix down the cylinder. Diaphragm felt pretty good when I took the carb apart, but I'll double check and run it through the ultrasonic cleaner while I'm at it.

 

[Keith Gandy]

Needle works? Not stuck?

 

[Deets066]

After you go through the carb again, try starting it without the air filter cover on. My choke doesn't close all the way and I've ground on everything in sight but not sure what it's hittin.

 

[huskihl]

After you go through the carb again, try starting it without the air filter cover on. My choke doesn't close all the way and I've ground on everything in sight but not sure what it's hittin.

Did you loosen the butterfly screws? That'll center the plate

 

[Deets066]

Did you loosen the butterfly screws? That'll center the plate

The plate moves freely in the carb, if I lift up the A/F cover it goes right to full choke. But with the cover down it only goes half choke

 

[huskihl]

The plate moves freely in the carb, if I lift up the A/F cover it goes right to full choke. But with the cover down it only goes half choke

The choke rod, over on the right, is it hitting something? Mine had to be straightened. It wasn't closing the choke all the way

 

[bikemike]

Can somebody please edumacate me on these tank vents ? The saw is a 034 Super that had been sitting for 10 years or so. The fuel line crumbled, so that got replaced, but the saw is still not drawing fuel. I cleaned carb pretty thoroughly with brake cleaner and then blew it dry with compressed air but the saw is still not drawing fuel. I'm convinced it may be this tank vent.

The tank vent has a forward facing screw, and then on the underside it has a very small screw on the inside. I did a google search on this and can't find a whole lot of info on this type of vent. I want to be able to clean it and ensure it's working properly.

BTW, this isn't my pic, just one I stole from google, but it's the same vent. View attachment 17736

Thoughts ??

Did you take a steel ring out of you intake boot where the carb gets bolted up? The way it's oval-shaped now leads me to think it has been missing for a while. Bet you need a carb kit too

 

[Deets066]

Not that I can see, I've clearance everything I thought could causing it, but no dice. I'm sure it's something small catching somewhere

 

[Deets066]

Did you take a steel ring out of you intake boot where the carb gets bolted up? The way it's oval-shaped now leads me to think it has been missing for a while. Bet you need a carb kit too

The pic isn't his saw

 

[bikemike]

The pic isn't his saw

Thanks I didn't read that part coffee hasn't kicked it to help my dislexic reading skills

 

[Honest John]

And the winner is.......Carb !!

After cleaning and rebuilding with new diaphragm and a bazillion soaks in the ultrasonic cleaner it still wasn't getting fuel. I finally gave up and borrowed the neighbors 034 and switched carbs for one that I know works and the saw fired right up, no ifs, ands, or buts.

Can't for the life of me figure out what the problem was with the old carb, but a new one is in the mail.

Thanks for the help gents.

 

[5000+]

Disassemble the carb. Check thre small round screen, make sure it is clean, remove it. With the needle valve, out hold carb up to a light, can you see thru the hole in the seat. Usually there is not much can't be fixed. Also check the fuel line nipple for cracks and looseness.

 

[Keith Gandy]

And the winner is.......Carb !!

After cleaning and rebuilding with new diaphragm and a bazillion soaks in the ultrasonic cleaner it still wasn't getting fuel. I finally gave up and borrowed the neighbors 034 and switched carbs for one that I know works and the saw fired right up, no ifs, ands, or buts.

Can't for the life of me figure out what the problem was with the old carb, but a new one is in the mail.

Thanks for the help gents.

That irratates me when i cant figure out exactly what was wrong? A new carb will usually fix alota problems though