No high speed run

[jkovalcik]

I have a 1986ish Honda Spree and it has sat for a while. I removed fuel and replaced and cleaned out the carb as per one of the posts (excellent instructions). The engine starts and runs at idle fine but when you accelerate, it boggs down and never runs up to full speed for more than a few seconds. I thought that it might be that the fuel bowl fills up and then does not refill. I played for awhile but dunno if I want to get another carb or investigate the theory that 90% of carb problems are electrical. There is also what appears to be a one way valve / diaphragm in the fuel system that I do not know what it does. Any clues?

[Johnniespeed]

The "one way valve / diaphram in the fuel system " , if you are talking about the valve that is attached to the bottom of the fuel tank, it is commonly called a petcock. It is a fuel shut off, what it does is to shut off the fuel to the carb when the engine is not running. When you start the engine vacuum pulses inside the intake, create a vacuum signal to the petcock diaphram, it pulls the diaphram open and fuel flows to the carb. Older motorcycles have a manual petcock where you manually turn the fuel on before starting and off when the engine stops.
As you probably already know the Spree is extremely sensitive when it comes to the fuel and intake system. Is the air box, air box tube, air filter, lid, lid screw and lid gasket all in place properly ? Sprees are great little scooters and run great when the intake system is exactly how the factory made it.
Dont give up, keep trying to get it perfect, they are a lot of fun to ride.
I would like to change your saying to say that 90% of Spree carb problems are air cleaner problems.

[ppat0324]

I am wondering if my '86 Spree is having the same problem? I seem to be having a vacuum problem. It has no performance or power. Is it possible the fuel valve line is pinched or should I check the air box first?...ppat

[patthesoundguy]

The air box is most likely your issue. Pull the air box lid and have a peek at the foam air filter element. It has to be in good shape and properly oiled with hear oil as laid forth in the manual. Make sure the lid has a proper foam gasket. Check the hose from the air box to the carb and make sure the clamp is on the carb so the hose isn't leaking. With out the air box in proper order the motor on a spree will refuse to rev up. Also check the vacuum line that goes from the intake tube to the bottom of the fuel petcock make sure it has no leaks or cracks, I'd replace the fuel line and vacuum line anyway. The original vacuum lines tend to rot and leak where you can't see. Another good idea of you suspect a fuel issue is to drain the tank and clean the screen on the petcock that goes on the tank. They can get gummed up when the scoot sits with a half tank of fuel then you run out of fuel with half a tank