Engine bogs up hills, fine on level ground
Posted: Thu Oct 23, 2008 9:57 pm
I have a Spree I bought new in 1986. I put 3000 miles on it the first three years and haven't ridden it since. Now I've gotten it running again--new tires, battery, air filter, cleaned the carb, new plug, new fuel lines and such--and it ran great, briefly.
It started to lose power while going up hills--first just a little near the top, then eventually it would completely bog down halfway up the hill. For a while, if I kept the throttle halfway, the engine would keep running but if I opened it up, it would completely die. I know, it's only a 50cc engine, but this isn't an issue of being underpowered since I was able to climb the hills originally (I'm 130 lbs.). It's not a pulley problem either since the engine doesn't rev on the hills.
It had some rust in the tank so I put an inline fuel filter but that quickly became clogged. I bought a different tank that looked clean inside, put that in, cleaned the carb, removed the inline fuel filter, put in fresh gas. It was marginally better at first but after a couple of miles it's bogging on the hill again. Thing is, it's always fine on level ground.
The petcock valve seems to be working (no fuel leaks if there isn't a vacuum, fuel flows when I suck on the vacuum tube). I've taken the exhaust off and while there is carbon on the surface, there's no buildup. Did a plug chop--that looks good.
Does anyone have any suggestions for what to do next aside from selling the thing for parts? What would cause this problem?
It started to lose power while going up hills--first just a little near the top, then eventually it would completely bog down halfway up the hill. For a while, if I kept the throttle halfway, the engine would keep running but if I opened it up, it would completely die. I know, it's only a 50cc engine, but this isn't an issue of being underpowered since I was able to climb the hills originally (I'm 130 lbs.). It's not a pulley problem either since the engine doesn't rev on the hills.
It had some rust in the tank so I put an inline fuel filter but that quickly became clogged. I bought a different tank that looked clean inside, put that in, cleaned the carb, removed the inline fuel filter, put in fresh gas. It was marginally better at first but after a couple of miles it's bogging on the hill again. Thing is, it's always fine on level ground.
The petcock valve seems to be working (no fuel leaks if there isn't a vacuum, fuel flows when I suck on the vacuum tube). I've taken the exhaust off and while there is carbon on the surface, there's no buildup. Did a plug chop--that looks good.
Does anyone have any suggestions for what to do next aside from selling the thing for parts? What would cause this problem?