038mag BOGS at WOT

[stihl038x2]

Here goes........ 038 mag, new rings, mild port job ex. opens 99* atdc,int. opens 75* btdc lower trans cleaned up.No base gasket,170# comp on new rings. Muffler mod. New carb kit,air filter,fuel line (aftermarket).Monkeyed with jets..lean,fat with no real improvement with the "bog"issue.
Idles great, revs "snappy", lots of rpm's out of the wood put it into a cut & 1/2 way thru bogs & sometimes dies. Take out of wood 1-2 pulls it's running again.
What could be the cause ??

thanks,

Steve

 

[burnses]

fuel starvation of some kind...

 

[Duane(Pa)]

The choke flap return spring needs 3-4 coils cut off and re-attached. She is sucking the flap closed and shutting down.

 

[Duane(Pa)]

To test my theory, run it without the air filter and report back...

 

[stihl038x2]

Tried that(no filter), didn't work. Still bogged.
I pulled the carb & stripped it down again, it was clean as can be. Pressure & vac tested the a/m fuel line & no leaks.
STUMPED !!!!!

Steve

 

[Robin Wood]

what about your chain and bar condition ?
i have an 038mag, they hate old gas

 

[Duane(Pa)]

Mastermind had some bad AM fuel filters. Same symptoms. Might want to try OEM FF?

 

[Sprintcar]

When you say "lots of RPM" is it four stroking with no load?

Go one full turn on the high side and report back.

 

[lone wolf]

Here goes........ 038 mag, new rings, mild port job ex. opens 99* atdc,int. opens 75* btdc lower trans cleaned up.No base gasket,170# comp on new rings. Muffler mod. New carb kit,air filter,fuel line (aftermarket).Monkeyed with jets..lean,fat with no real improvement with the "bog"issue.
Idles great, revs "snappy", lots of rpm's out of the wood put it into a cut & 1/2 way thru bogs & sometimes dies. Take out of wood 1-2 pulls it's running again.
What could be the cause ??

thanks,

Steve

You had this saw or just got it?
What did it run like before?

 

[stihl038x2]

Four strokes no load then leans out.
Saw ran great before new Caber rings, only put ring on because she was open to get ported.

Steve

 

[lone wolf]

Four strokes no load then leans out.
Saw ran great before new Caber rings, only put ring on because she was open to get ported.

Steve

I need to know what order of things? Was it ported before or after the problem etc? Was the carb messed with ?

 

[drf255]

Check the tank vent too