traffic903
Pinnacle OPE Member
- Local time
- 9:55 AM
- User ID
- 3911
- Joined
- Aug 28, 2017
- Messages
- 343
- Reaction score
- 1,390
- Location
- Australia
My 660 problems are back. I thought I had them solved but no. I did rule out the coil, which is good. And, I have it narrowed down to the carb. So here is my problem.
Saw will start and idle perfectly. Will usually rev up fine and is tuned to 13000ish. However (especially once warm) then it will suddenly "flood" at high rpm. This drops the revs back to around 9-10000 and then if I let off the throttle it will mostly die.
I have taken off the filter and watched this as it occurs. It revs straight up to 13 then after about 2 to 3 seconds you can see fuel just pour into the venturi. I mean like a car wash! Why is this happening, and why does it mostly only happen once warm? I have set metering lever higher and lower for no difference. I changed the welch plug and added some sealer which helped for one tank, but now it is back to doing the same again. I have removed the needles and sprayed brake cleaner through the passages. Have changed metering lever spring. Renewed all gaskets.
I swapped my genuine 660 carb over to test and it runs perfectly. I have 3 chinese carbs. 2 do the EXACT same thing and the other is in the saw at the moment and is working so far, albeit with a slightly erratic idle.
What can make a carb basically flood at high rpm like this? Could it be something like some swarf moving around in a passage? A check valve? Alien? It just seems so weird that 2 different carbs would do the exact same thing in the same circumstances.
Am keen to hear some opinions if you could offer something please.
Saw will start and idle perfectly. Will usually rev up fine and is tuned to 13000ish. However (especially once warm) then it will suddenly "flood" at high rpm. This drops the revs back to around 9-10000 and then if I let off the throttle it will mostly die.
I have taken off the filter and watched this as it occurs. It revs straight up to 13 then after about 2 to 3 seconds you can see fuel just pour into the venturi. I mean like a car wash! Why is this happening, and why does it mostly only happen once warm? I have set metering lever higher and lower for no difference. I changed the welch plug and added some sealer which helped for one tank, but now it is back to doing the same again. I have removed the needles and sprayed brake cleaner through the passages. Have changed metering lever spring. Renewed all gaskets.
I swapped my genuine 660 carb over to test and it runs perfectly. I have 3 chinese carbs. 2 do the EXACT same thing and the other is in the saw at the moment and is working so far, albeit with a slightly erratic idle.
What can make a carb basically flood at high rpm like this? Could it be something like some swarf moving around in a passage? A check valve? Alien? It just seems so weird that 2 different carbs would do the exact same thing in the same circumstances.
Am keen to hear some opinions if you could offer something please.