Bike goes fast. Then really slow

[Landon Torppey]

Ok so I got a new bike kit. I put it together and it starts fine. I ride and ride and it seems fine. Then, about 25 minutes into riding the bike slows down. I thought maybe fuel?. I was fine. And was getting plenty fuel into the bike. I left it overnight and next day, it started fine and then like before 10 to 15 mins in it dies. It doesn't completley diet but it wants to and I need to keep pedeling just to keep her running. Also I have a minor carb leak. Any responses will be greatly appreciated. Thanks to all who try to help. Rock Hard, Ride Free.

 

[Neptunati]

You might have things that are solid when it's cool. As the engine heats up they liquify an open air leaks

 

[skyash]

Fix the leak. if if goes good then struggles might be dirt in the carby. It gets sucked up in to the jet and when you slow down in drops again. Just look in the carby pot /bottom of carby. Ezy to check

 

[Greg58]

I would check the torque of the head bolts, when the engine gets to full operating temperature you may be loosing compression. Also check the gas tank cap vent, some are blocked keeping a good flow of fuel from going to the carb. Or the magneto coil/cdi could be getting hot and weak.

 

[crassius]

if it sounds like it is 4-stroking when hot, you may be just a bit too rich so that it only runs well when cold - I'd first try dropping the needle down one notch to see if that makes a difference - if so, you'll know where the problem is

 

[45u]

Sounds like it is over heating and a leak of any kind can cause this problem because it is making it run lean. Just hope it did not mess up anything in the motor.