Shindaiwa 488 bogging down

[JohnK]

I may have posted this on the wrong forum earlier. Here it is again since there were no replies. My 488 bogs as soon as the throttle is squeezed. It starts fine and idles smoothly. The muffler screen is clear, the carby has been rebuilt. I have turned the Hi needle every which way but will not rev up with a trigger pull. From other posts this looks like a fuel line problem. Suggestions welcomed.

 

[Fatherwheels]

I may have posted this on the wrong forum earlier. Here it is again since there were no replies. My 488 bogs as soon as the throttle is squeezed. It starts fine and idles smoothly. The muffler screen is clear, the carby has been rebuilt. I have turned the Hi needle every which way but will not rev up with a trigger pull. From other posts this looks like a fuel line problem. Suggestions welcomed.

Its the low needle you want to screw out, but not too far either.
I would take off the muffler and look if there is any scoring on the piston or cylinder.
Did you check for physical blockages in around the clutch and flywheel, nothing
got in there to jam things up.
I presume you had a good look at the pipes when you did the carb, and the filter in the tank is clean or renewed.
Take bar and chain off and see if she will rev up, can the chain be turned by had,
its not being held back by the brake or anything wedged in around the clutch,
is the brake coming off when the flag is pulled back, not just the flag coming back but the brake still remaining on.
Hopefully you will get it sorted and its something simple.

 

[JohnK]

Its the low needle you want to screw out, but not too far either.
I would take off the muffler and look if there is any scoring on the piston or cylinder.
Did you check for physical blockages in around the clutch and flywheel, nothing
got in there to jam things up.
I presume you had a good look at the pipes when you did the carb, and the filter in the tank is clean or renewed.
Take bar and chain off and see if she will rev up, can the chain be turned by had,
its not being held back by the brake or anything wedged in around the clutch,
is the brake coming off when the flag is pulled back, not just the flag coming back but the brake still remaining on.
Hopefully you will get it sorted and its something simple.

I am extremely embarrassed to say I'd rebuilt the carby incorrectly, mistakenly putting components in the wrong order. Now that's fixed it's running like a charm. Thanks for sending me helpful hints and suggestions. Cheers.