570 X torq bogs when you give it WOT

[changetires]

570 X torq bogs down and will shut off when you give it WOT. Put a RB 130 kit in and it cranks easy and idles well. The adjusters have had the stoppers snipped off and I have tried adjusting them while cutting and not cutting but it will not get to top end. Also tried a new plug doesn’t help. It will run fine till about half throttle then the bog starts happening. Any help would be appreciated.

 

[Rogee]

H

570 X torq bogs down and will shut off when you give it WOT. Put a RB 130 kit in and it cranks easy and idles well. The adjusters have had the stoppers snipped off and I have tried adjusting them while cutting and not cutting but it will not get to top end. Also tried a new plug doesn’t help. It will run fine till about half throttle then the bog starts happening. Any help would be appreciated.

Have you replaced the fuel filter I had one that ran abit like that till I changed the filter and fuel hose

 

[changetires]

H

Have you replaced the fuel filter I had one that ran abit like that till I changed the filter and fuel hose

Yes new filter

 

[changetires]

Yes new filter

I also bent the needle valve arm up a smidge to see if the needle would open a little further but that didn’t change anything

 

[Stevetheboatguy]

I'm going out on a limb here. I can't exactly remember what a 570/575 carb looks like. But is there a chance the strato valve isn't opening properly? I seem to remember them having a goofy linkage set-up.



Steven

 

[cus_deluxe]

the strato on these is a seperate butterfly above the carb, and yeah there is linkage thats kind of a bugger. i assume you replaced/checked the screen in the carb? possibly losing crankcase pulse?

 

[changetires]

All the linkages are working and yes I changed the internal screen. Is the pulse line the small brass tube off the bottom of the carb that fits into the little tubing... it’s kind of a bugger to see and line up when reinstalling the carb?

 

[changetires]

Update
The pulse line was clear and blowing out when I pulled the rope.
With the saw running and I give it enough throttle the saw will start bogging when the lower butterfly starts to open and when you go WOT it starts blowing air out while it try something to bog down.
Is the saw low on compression? I tried to perform a compression test but it would not pump up any pressure on the tester gauge.... am I missing something?

 

[cus_deluxe]

Is the saw low on compression? I tried to perform a compression test but it would not pump up any pressure on the tester gauge....

sounds like thats a place to revisit...

 

[changetires]

Rechecked the compression again tonight... gauge just flutters when pulling cord and holds zero pressure. Taking the muffler off tomorrow and have a look.

 

[Barn Shop]

Check the Arestor Screen

 

[ucm931]

Rechecked the compression again tonight... gauge just flutters when pulling cord and holds zero pressure. Taking the muffler off tomorrow and have a look.

Also make sure the compression tester is workin right with a known good saw. Almost sounds like the schrader valve might be loose or something. The guage shouldn't just flutter......it should hold any pressure that builds.

 

[changetires]

Update
Found the piston was scored on the muffler side... took the topend off and the top half of the piston appeared to have experienced some excessive heat.... ordered another 49mm piston kit and a decompression plug and gasket set.... will update after rebuild

 

[Nutball]

Pictures?

 

[changetires]

Update
Cleaned up the piston with some 400 grit.... put a new ring on it.... new base gasket with a light skim of grey gasket maker... new circle clips
Fired off on the third pull and let it warm up and went to cutting WOT