OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters Masport SR-25 Brushcutter

Hello

I have a Masport Sr-25 Brush cutter I believe it sais maid by Shingu. It has a Walbro WYJ 151A - 031 Carburettor on it. Recently the wife went to start it and it starts fine but wont rev at all. sounds like it is being held back and cant get enough to run right. I have checked the exhaust as we have had wasp nest in outlet hole before clean and fine. Checked and replaced with fresh new fuel. Checked and cleaned the spark plug. Pulled the carburettor cleaned blown out. Checked and cleaned air filter. All this and still the same. I noticed while blowing air toward the air filter housing it would increase the revs and start to sound normal. What am I over looking. Annoyingly before this when put away last time it ran fine. This machine has been brilliant the whole time we have owned it and starts first time every time. So good my 45 kg wife with chicken arms can start it first time every time. I just don't know what I am missing and it is getting to me. The wife is nagging me to fix it to.

Any Clues

Regards
Leshby

leshby,

Try replacing the fuel filter in the tank first before looking at the diaphragms.

Does the exhaust have a "Spark Arrestor screen"?..If so Maybe checking to see if it clogged up may be worth trying... Maybe a carby adjustment (H & L)?

Hello,
This model carburettor Walbro 151A-031 WJY has no adjustments only idle screw. The exhaust I have dismantled and fully cleaned out. It has a screen and some kind of material behind it on the inside surface of one half of the exhaust. I have cleaned this also. Then I have reassembled the exhaust.

what about the fuel cap 'Vent"?..i have seen blocked 'breathers' in fuel caps cause weird problems too