Sun-l 90 speed control
 

Got our sun-l 90 running again. Giving it to our middle grandson, I turned the throttle screw all the way in, Yet it still run's at full speed. Is there any way I can turn this quad down to run about 10 mph. Any comments would help. Thank's.

Sun-l 90 speed control
 

the screw at the thumb control is used only as a stop, not allowing you open the throttle up, so i would think if you're still able to screw it in all the way and its still able to run wide open, then it's broken and the thottle assy needs to be replaced

Sun-l 90 speed control
 

take the nut off. that might help too.

Sun-l 90 speed control
 

Put a spacer(made of whatever you choose) on top of the carb slide so it can only go so high. That will regulate top speed.

-d3

Sun-l 90 speed control
 

SIMPLE,
take the screw out and run down to your local hardware and ask them to give you the same screw but you want it one quarter inch LONGER than the factiory one.

This will do the trick!

Sun-l 90 speed control
 

Thank's for the reply's. I did remove the nut on the adjustment screw and turned it all the way in. Still run's at full speed. I'll try to put A spacer in at the carb and see if that works. I will let you know. If that don't work I guess I will replace the throttle assy. Thank's again for the reply's.

Sun-l 90 speed control
 

Middleaged,

Before you mess with the carb, on some of these the screws are too short so even when you put them all the way in it does not touch the throttle. Take the thumb throttle cap off and you can see where the screw is. If it is too short then get a longer one and this should take care of it. Be very careful and inspect the throttle where the screw hits because some of the quads will have problems with the throttle sticking wide open. This happened to me and I found that the screw would slide under the throttle and bind on the treads and stick open. I took the screw out. You can see if it will happen by adjusting the screw in and hitting the throttle while the top is off (motor off). If the screw hits nice and center of the throttle then you will be fine. If the screw has a tendency to go below the throttle it will stick. This only happens when you try to limit the throttle real low. Not so much with the upper limits.

Sun-l 90 speed control
 

Ok, Just letting you all know that I replaced the set screw with A longer one. Everything lines up good and the quad now just putt's around. It's all good.[img]i/expressions/face-icon-small-happy.gif[/img] Thank you all for your help.