MS880 Running rich (modded)

[silverpsd06]

I have woods ported a MS880 and swapped coils to the unlimited 088 coil.. After assembly the saw will not lean out on the high needle, high needle will respond with more fuel but nothing less even seated snug. Low responds normally. I have tried adjusting timing from slightly advanced to extremely retarded and everything in between, no considerable difference. Am I overlooking something? Saw was a solid runner before modding..

 

[Powerstroke Cowboy]

Just to clarify, it ran good ported? But not with the new unlimited coil? Was the coil the only change that was made before the said problems?

Is your the new style ms880 or old style ms880? Clip on muffle or bolted on muffler?

 

[Maintenance Chief]

Did you pressure test the pop off of the carburetor? Could just be trash under the needle.

 

[silverpsd06]

Pressure tested the carb to 15PSI, saw was a runner before any mods, has a cast aluminum muffler (clip on and has been modded albeit ugly). Taken carb apart, removed needles and brake cleaned through them no change. Is there a bypass circuit in these carbs? It's a Walbro.

 

[Ketchup]

Both gates are operating through their full range? Filters are clean? Lever seated properly under diaphragm?

 

[silverpsd06]

I think I have found the solution to my issues, going to experiment with plugging one of the jets inside the carburetor. Will report back carburetor is a WG-12A.

Filters aren't new but definitely not dirty enough to cause this issue, both needles will work through full range of leanest setting to richest.

 

[Ketchup]

I meant the throttle and choke gates/butterflies. The choke vein on my 394 got stuck partially closed and gave me fits. I’ve also had lots of problems making my own throttle linkages that didn’t open the throttle all the way. The last 10 degrees make a big difference.

 

[silverpsd06]

I have not investigated that but I will take a look at them. I'd assume they're fine since it's all OEM