Issue with my Tanaka

[shawnshank]

I have a 40cc tanaka GEBE kit and I rode it the other day and it was fine. Fast and smooth as usual.
However, when I started it up today, it seemed to be idling a little lower than usual. When I took it out for a test ride, it seemed a little sluggish off the start and slow to get up to full speed. Once it reached top speed, it seemed to slow down sporatically. It wasn't a drastic slow down, more like somone was hitting the brakes randomly just enough to get the brake pads to touch the rim and then off again. The engine sound didn't change at all so it's not like it's sputtering or anything. It's the strangest thing and I've never had an issue with it so it's surpising. Any ideas what it might be?

 

[augidog]

guesses

- spark plug (the likely culprit)

- air filter

- bad fuel (or wrong ratio?)

- pinched or shrunken gas line

any new or unusual clutch noise?

sometimes when i start my 40 i accidentally nudge the choke on a bit.

 

[Esteban]

I have seen so many fuel problems , I am going to say start with that. FRESH NEW fuel , in a CLEAN can, & oil.

 

[Tanaka40]

Fresh Fuel and a new spark plug (or at least a cleaning). Fuel only stays fresh for as little as 30 days. My dad had a small engine repair business and you would be amazed on how may pieces of lawn equipment that were brought in for bad fuel and a fouled spark plug. (7 out of 10)....and while your there, cleaning the air filter is a great idea for the new season.