028 AVEQ questions

[Mark71gtx]

A friend dropped off his 028AVEQ saying it was sick. I took it for a spin today and he is right... It is blowing 150psi and passes pressure and vacuum tests. The saw just don't have any power. The clutch had weak springs, so I replaced them. The drum is in good shape. The sprocket is in good shape. The chain is not the sharpest, but I have tested worse and had better results. You have to fight the saw through a 6" limb. It is just weak as hell. Carb is a Tillotson and is clean, with pliable diaphragms. I have not changed the plug, but the plug looks good with a tan colored electrode. With this info and symptoms, what is your best guess as to the culprit?

 

[Warped5]

In order:

How's the spark screen look?

Air filter?

I'd still put in a carb kit and clean it ....

 

[czar800]

^^ what he said ^^

 

[Frogfarmer]

Exhaust port could be completely carboned up. Open the muffler and get a good look. Get it warm and try it without the air cleaner.

 

[Mark71gtx]

How's the spark screen look?
Non existent

Air filter?
I've seen worse, I do plan to replace it though.

I'd still put in a carb kit and clean it ....
My original plan was to rebuild the carb, but it was so squeaky clean I thought I might be wasting my time.

 

[Czed]

Mine had the flocked filter that was deteriorating and was hard to start low on Power even though it has 185 psi and a new carb kit fuel and impulse lines switched to a new screen style filter really woke it up easy to start and good power.

 

[Mark71gtx]

Filter first! Thanks!

 

[drf256]

IIRC, the 028 has the choke flap I the air filter, like the 26.

Make sure the flap isn't closing or partially closed as well.

You can retune and run it without a filter for a cut or two, just for a diagnosis.

 

[Mark71gtx]

I forgot to mention earlier that the exhaust port and P&C all look good. The owner only runs trufuel in it, and the previous owner is known for taking care of equipment. With the saw being so old, it is likely that the choke flap is closing up.

 

[fearofpavement]

I think if the choke was closing the saw would be running rich and the plug color would reflect that. Check the carb, fuel line and impulse line.
Have you tried opening the H about 1/4 turn?

 

[fearofpavement]

One other thing is there could be a restriction in the muffler itself. You can take the muffler off and run it for a cut and see if there's a significant change. (Don't run it much with no muffler, just to test it for a cut.)

 

[Mark71gtx]

I did a lot of screwdriver tweaking on it to no avail. I have a filter on the way. If that don't solve the issue, it will get new lines, filter, and plug. The muffler is clean. It is a 028, so there is not much to the muffler to start with...

 

[Adirondackstihl]

Fuel filter

 

[Duane(Pa)]

Fuel filter

This, and depending on the type of filter, it may have puked it's guts (disintegrated foam) into the carburetor screen.

 

[Adirondackstihl]

This, and depending on the type of filter, it may have puked it's guts (disintegrated foam) into the carburetor screen.

Yep

 

[Mark71gtx]

I'll look into all of these. It will be getting new filters regardless. I like to try them before doing too much to them to get a baseline of performance before making repairs.