Basket case 029

[jackjcc]

Guys I’m out ideas on this 029...

The saw starts on 3rd or 4th pull. It runs for 5 minutes and then struggle and dies. It used to basically die out in the cut and would not restart unless it was cooled off, so I swapped out the coil with an untested used one, same issue. Now I’ve swapped out the entire electrical system from an ms290 flywheel included. It ran for a bit longer today and I got through some 5” test cuts when it started bogging out again, it sounded like when you have the choke after it’s warm, starts to die off. The real difference here is that it restarted on one or two pulls.

So I thought maybe the tank vent but after opening the gas cap it was still bogging after starting and would die out.

I’m gunning plug the fuel line in and vac test it. Please post up some ideas fellas...I’m about ready to tomahawk this saw across the driveway.



Sent from my iPhone using Tapatalk

 

[brandonstc6]

Carburetor or fuel line issue?


Sent from my iPhone using Tapatalk

 

[jackjcc]

It has a brand new fuel line and carb kit, no clue what issue would make a carb stop working while operating?


Sent from my iPhone using Tapatalk

 

[jackjcc]

Well I had an absolute fail testing the tank vent, fuel everywhere. Once I got smart and removed the tank vent to test it was easer.

Current vent is the little screw into a piece of fuel line that was about 5 psi a minute loss. Seemed slow. In comparison a new style vent off an ms290 didn’t even register pressure vented almost as fast as it was built, couldn’t get it to 5 psi. So I’m thinking I found the problem, but what is an easy solution for replacing that vent?


Sent from my iPhone using Tapatalk

 

[jackjcc]

We will see how this works out tomorrow. Just used the 290 vent I had on hand and drilled a small hole same spot as on the 290.


Sent from my iPhone using Tapatalk

 

[a. palmer jr.]

Those vents usually work pretty good. The straight hose works too as long as the screw doesn't completely block it.

 

[log_jammer]

Did you use an OEM fuel line. Aftermarket ones are junk IMHO. For that model anyways...

 

[Hdtoolmkr765]

What is compression?

 

[grizz55chev]

Check the impulse line for cracks.

 

[a. palmer jr.]

Did you use an OEM fuel line. Aftermarket ones are junk IMHO. For that model anyways...

Yeah, I bought some of them a couple of years ago and so far every one I tried had a kink near where it hooks onto the carburetor. You can always cut the center grommet out of the line and use it with regular Tygon fuel line..

 

[Okie]

If that is the type vent with two grub screws, do not twist the grub screws into the vent line, push them into the tubing which will allow more venting around the grub threads and some lines are just to soft to use as a vent tube with the grub screws. You can test the tube for venting with a vacuum gauge. I've made grub vents by cutting the head off of small machine screws. I suspect you might still have a run issue other than tank vent.

Well seems you eliminated the ignition except for spark plug. (I sure feel weak (upstairs) when I've flogged one for awhile and find a bad measley spark plug)

Also check the muffler spark arrestor screen or remove it for a test run. (give the screen a toss)

You can vac test both the impulse line and the fuel line. If not the carb you might have to check the intake manifold rubber boot (between the carb and the engine) for a crack.

A Stihl carb is about same price as their kit.
I've used the $10 ebay China carbs on a Stihl chainsaw just to get a test run (too make sure it's carb problem) but do not leave the China carb on the saw permanently. (I do not really trust the China carb on a good saw, can lean out easily and ruin a good saw engine fast)
Some OEM Stihl carbs are very reasonable priced especially when compared to the price of a OEM Stihl carb kit and time involved in cleaning and kitting.

Take some extra strength Midol and remain calm. (The Midol helps with reducing the effects of cramps and headaches when working on Poulans and Crapsman saws)
Poulan and Crapsman should add this tip to their owners manual troubleshooting section for their saws.