Poulan Countervibe 3400 "Fun"!

[seagiant]

Hi,
Thanks, have already rebuilt the carb and it pressure tests fine.

All I know to do now is install new rings and maybe new seals...

If I can find a press/vac leak that might explain the won't run problem.

Rather find it and fix it, than keep dealing with it!

 

[9050lx]

still think carb problem is there.I also vote ultrasonic clean.

 

[seagiant]

Hi,
Well, I have an ultrasound, I can put it in, and try I guess?

 

[9050lx]

check for crud under plate gasket, where check valve filter resides.

 

[seagiant]

Hi,
Well, did the ultrasound, got it back together and does the same thing...

I shoot a little mix in the carb, it fires off, and runs about 3-4 sec. and dies???

I guess now I can tear it apart, change the ring out, press/vac test the seals, and go from there.

I do not see this Carb for sale anywhere are they no longer made?

I've done everything I can do with this one, if it is the problem?

 

[9050lx]

Does it pump fuel?

 

[seagiant]

Does it pump fuel?

Hi,
Thanks, yes, it seems to, from what I can see thru the new fuel line.

I just ordered a new check valve kit for the carb, and I'm setting up to do a press/vac test on the case.

 

[Bob Hedgecutter]

What kind of fuel ratio are you using? 33:1 ish?
Only reason i ask is if the combustion chamber is getting fuel, plug is delivering spark- about the only thing that can be letting you down is compression.
If in order to get it to pop run or whatever it has been doing previous to all the carb fuddles- if you were pulling the recoil rope like a schoolboy for 20 or so times, then a wee prime and it fires- could be you pulled enough fuel mix to oil coat the top of the piston/side of the cylinder with enough oil to temporarily take up the slack of worn rings.
The old redneck compression tester- teaspoon of oil down the plug hole, fit plug and try to start it.

 

[seagiant]

What kind of fuel ratio are you using? 33:1 ish?
Only reason i ask is if the combustion chamber is getting fuel, plug is delivering spark- about the only thing that can be letting you down is compression.
If in order to get it to pop run or whatever it has been doing previous to all the carb fuddles- if you were pulling the recoil rope like a schoolboy for 20 or so times, then a wee prime and it fires- could be you pulled enough fuel mix to oil coat the top of the piston/side of the cylinder with enough oil to temporarily take up the slack of worn rings.
The old redneck compression tester- teaspoon of oil down the plug hole, fit plug and try to start it.

Hi,
Thanks, I've got it torn down already...

Want to press/vac test, then change rings and go from there, but will remember...

The oil test!

 

[Chevboy0167]

The extra oil trick works temporarily. I did that on a coworkers old Echo string trimmer with 82 lbs of compression last summer. Heck...it even ran previously at that reading. Got it bumped up to 95 psi running 32:1 mix. from his 50:1. Still runs to this day I think! LOL

He got it for $50 used and did not want stick any money into it. Old gray SRM225. Godspeed little trimmer!

 

[9050lx]

Well if you reassemble without base gasket, should bump compression.those wide rings should still have some tension. Something fishy. would expect it to run with 110 comp.how was impulse gasket?

 

[seagiant]

Well if you reassemble without base gasket, should bump compression.those wide rings should still have some tension. Something fishy. would expect it to run with 110 comp.how was impulse gasket?

Hi,
Made a new gasket so it is good...

I doubt the problem is 108 compression, but while I'm in it, may as well pull cylinder, inspect, and change rings to make it as good as I can.

Still feel it is a fuel problem but can't figure it out and fuel lines and vent lines new and tested???

On the bright side, learning about Poulan Chainsaws, getting more specialty tools and having fun!

There is another Poulan 3400 up for grabs in June...

Going to try and get my hands on that one too!

 

[seagiant]

The extra oil trick works temporarily. I did that on a coworkers old Echo string trimmer with 82 lbs of compression last summer. Heck...it even ran previously at that reading. Got it bumped up to 95 psi running 32:1 mix. from his 50:1. Still runs to this day I think! LOL

He got it for $50 used and did not want stick any money into it. Old gray SRM225. Godspeed little trimmer!

Hi,
I have that machine and it is worth repairing to my mind.

The only trimmer I like better than an ECHO, is a Shindaiwa!

 

[Chevboy0167]

^^^^^ Yup. I have an SRM230 gray model for 24 yrs now. Still going strong!

 

[RedneckChainsawRepair]

I had to help a guy not long ago troubleshoot a carb he rebuilt and put wrong parts in from the choices in the kits. Make sure all match what you took out if it was working when removed.

Almost has the same sounding issue you are saying. http://chainsawrepair.createaforum.com/carb-fixes-and-mods/craftsman-3-7-won't-pick-up-gas/

 

[dboyd351]

I had to help a guy not long ago troubleshoot a carb he rebuilt and put wrong parts in from the choices in the kits. Make sure all match what you took out if it was working when removed.

Almost has the same sounding issue you are saying. http://chainsawrepair.createaforum.com/carb-fixes-and-mods/craftsman-3-7-won't-pick-up-gas/

Good advice.
Also a good idea to look up and print out an illustrated parts list (IPL) for your model of carb to use as a guide for which parts go where when you go to reassemble it. Or you can take pictures with your cell phone as you take apart to help with which order and orientation is correct for reassembly.

 

[seagiant]

Hi,
Thanks Gentlemen, but that is not the problem...

I have the rebuild kit in correctly and this problem, what ever it is...

(I have a new check valve in the mail coming for the carb and will put that in.)

Happened with the Carb when I got the Saw and is still happening with the now rebuilt Carb with the OEM Kit.

I was missing the duckbill on the end of the vent line in the gas tank so that is coming but not the problem as I vac tested the tank and the vent is working (Tank will not hold Vac and bleeds off as designed.)

Waiting on a few tools and need to make a block off plate for the cylinder, so I can press/vac test case.

Might as well see what is going on there and replace rings to get compression up.

Learning everyday and enjoying this Poulan, which I had thought at one time was all junk Saws!

Live and learn!

If I need to pull and replace the crankseals, do you guys just pull them with a wood screw?

I don't want to split the case if I don't have to?

 

[9050lx]

My last 3400 had the wrong plate gasket in the carb from previous owner.Fortunately dumbass me finally spotted it.I'm sure thats why I got the saw cheap.

 

[seagiant]

My last 3400 had the wrong plate gasket in the carb from previous owner.Fortunately dumbass me finally spotted it.I'm sure thats why I got the saw cheap.

Hi,
I assume you are talking about the gasket between the Carb and the Cylinder?

I made a new one, it seems to have a small hole for the Carb impulse action at the bottom.

 

[9050lx]

No. the plate gasket under the needle and seat over the check valve.OEM kits supply two versions.Install the wrong one and it starves fuel at idle.Could try opening high side a half turn or so and opening throttle half way and see if it runs.