no power under load. cause???

[Wrench]

Maybe it's the summer blend gas, none of my bikes seem to run as good as they have. They rev fine but don't pull as well as they did in the winter.

Nope not the gas
Winter cold air has more air molecules, More air molecules mean more energy released, means more power,
So yeah, your engine runs better when temps are cooler outside

 

[Wrench]

Blend of gas is all about how fast the gas will evaporate to reduce emissions in our atmosphere
Summer Blend evaporates more slowly than Winter Blend
But Winter Blend ignites more easily, so a car is easily to start on those cold mornings
Winter Blend is cheaper to produce than the Summer Blend so gas prices go down in the winter while gas prices go up in the summer

That's the theory anyways

 

[Chainlube]

Maybe it's the summer blend gas, none of my bikes seem to run as good as they have. They rev fine but don't pull as well as they did in the winter.

Engines run better in cooler weather, denser air. Put an ice pack on your carb.

 

[GW's Motorized]

Engines run better in cooler weather, denser air. Put an ice pack on your carb.

Longer intake tube can help wit that too. The cooler gas will help also.

 

[Deleted member 33388]

Perhaps a tiny coolcan for the gas line.

 

[michael whiteman]

Chainlube knows. It's all about ambient air density. Try readjusting your air/fuel ratio.

 

[Wrench]

Air Density -like air pressure decreases with increased altitude. It also changes with variations in atmospheric pressure temperature and humidity,

Yep, an air/fuel adjustment is necessary

 

[Jayraye39]

So i cleaned my carb and nothing changed. But now it seems to get better everytime I ride it. while riding wot i put my finger partially over the carb hole and it started to accelerate faster. then I did wot throttle again without my finger over the whole and it started to accelerate faster also. how does it start get better everytime I ride it? My idle is not climbing so it cant be a leak. it almost feels Like its cleaning itself out. makes no sense to me.

 

[Jayraye39]

I did sand the head chamber squish area a bit just to clean it and make it smooth. you think losing a tiny bit of squish band clearance would make that much of a difference?

 

[Chainlube]

I know when a chainsaw loses top end, 90% of the time it's the spark arrester that is clogged. Try looking for a blockage in the exhaust.