70cc DAX motor only going 15 mph need help

[Skyline PDR]

Hello eveyone, this is my first time posting I hope someone can help. My bike is only getting up to 15mph. I have tried a few things but it still not getting the full power. It is a dax 70cc. It starts up fine but when it gets to full throttle it just seems like it can go faster but something is holding it back. My next thing I guess I could do is clean the carb and gas tank.

[Ilikeabikea]

Welcome to the forum, You'll like it here. Lots of motorized bicycle enthusiasts. Do you have an inline fuel filter between the tank and the carb? If you don't that would be the first thing I would try. You might try a different plug and plug wire. If that don't work let us know. It'll go faster than 15 mph when you get all the bugs worked out.......................

[paul]

also make sure you do not have any air leaks to the bicycle motor from the carburetor. a way to check that is spray a little starter fluid around the intake manifold where the carburetor bolts on. just a little and if it revs up you know where the problem is

[misteright1_99]

You also want to check to make sure your throttle is adjusted properly, that the slide in the carb opens completely, and that the choke is wide open,,,,

[Bikeguy Joe]

Skyline- Welcome to the place.

Places to start- Check your spark plug- should be a chocolate brown, not oily and black or grey/white.

Double check the tightness of the manifold bolts and the carb clamp.

Post back here when you do those things and let us know what you find....we'll get yer' motor runnin'!

[deacon]

If i were a betting man I would bet on an air leak at the car manifold connection is by far the most common first problem with a build. It would also act as you describe.

[Skyline PDR]

Thanks for the info I will put one on today.

[Norman]

your chain isn't too tight is it? what size rear sprocket you running? your brakes aren't dragging? tires inflated to the proper pressure? axle bearing greased and adjusted so they aren't too tight? also the dax will need to be broken. All of these 2-stroke engines will run poorly until they get about 2 or more tanks of fuel run through them. I'll run about 20 to 1 for the first tank then I go to 30 to 1 after that. My dax engine had 2 base gaskets and I removed them and played with the thickness of the base gasket to make it run bettee along with that you will have to make sure you don't hit the head with the piston.

[Skyline PDR]

Thanks for all your input. I did everything that yall suggested and you know what the problem was. My air box on the carb was to close to the frame so I put the filter right up against the carb without the box and it was flooding it when I had it throttled. I did not think that the filter could block it that much to make it flood. It is a new motor but I just couldnt resist full speed. The mixture right now is still 20 to 1. Thanks everybody

[Skyliner70cc]

15mph, its on par for a Dax