Drive chain, Chain slack adjustment, Throttle lever – Eton VECTOR 250R User Manual
Page 21: Adjusting the throttle cable

Page 20
Drive Chain
The drive chain will stretch with use and will 
require periodic adjustments. To check the chain 
tension, remove the chain guard and measure the 
slack. 
The amount of slack in the chain should not 
exceed 10-20mm or ¼” - ½”. 
 
Inspect the drive and axle sprockets for worn, 
damaged or broken teeth. Replace as needed. 
Inspect the chain links for damaged, worn or 
loose rivets. Repair or replace as needed. 
Chain Slack Adjustment
 
 
 
 
 
 
 
 
 
 
 
 
Loosen the axle position lock bolt slightly and turn 
the chain adjuster nut to take up the excess slack 
in the chain. Once the chain has been adjusted 
to the proper tension retighten the axle position 
locking bolt. 
The chain should be kept well lubricated to 
prevent excess wear and premature failure. We 
recommend that you lubricate the chain every 15 
hours of operation, or more frequently if needed, 
with a high quality chain lubricant. 
Throttle Lever
The throttle lever is located beside the right-
handlebar grip and is operated by using the right-
hand thumb. The lever is spring loaded and will 
return to the idle position when you remove your 
thumb from the lever. To accelerate the unit, simply 
press the lever forward to open the throttle slide in 
the carburetor. To slow the unit, reduce the pressure 
on the lever or remove your thumb and the throttle 
will return to the idle position automatically. 
 
 
Adjusting the throttle cable 
 
