Idling issues
To adjust the idle on your engine, using a screwdriver, locate the black plastic screw head on the back of the carb under the black air filter cover. Turning the screw left or right will increase or decrease the idle speed. With the engine running, adjust the idle screw until you are satisfied that the engine can tick over without the throttle needing to be applied, however the rears should not be spinning (ideally not at all, or certainly not quickly).
If you have tried to adjust your idle screw but have found that it hasn't changed the idle speed, this may be linked to a known issue identified during the Test Day Event: a limited batch of engines have the throttle pivot spring locating hole drilled in the wrong place, preventing the spring from working effectively. This can cause issues with damage to clutches and chain guards due to excessive heat build-up, along with drivers not retaining full control of their kart.
If you believe your engine may have this issue, you can either contact jake@espireeducation.co.uk or complete the following steps:
1. Remove the air filter cover and air filter.
2. Remove the two carburettor nuts (the carb does not need completely removing) — see the image below.
3. Slide the carburettor away from the engine to loosen it, which will allow the spring to be removed from the underside of the throttle arm (take note of where the spring is located on the carburettor, as it will likely become detached during this process and will need re-attaching).
4. Mark and drill (3mm drill bit) a new locating hole in the throttle arm — 42mm from the centreline of the small hole to the edge of the large hole, as shown in the image below.
5. Attach the spring in the new hole.
6. Re-fit the carburettor and tighten the two nuts.
7. Re-fit the air filter.
8. Re-fit the air filter cover.
9. Check throttle pedal movement and adjust cable clamps if required.
Carburettor nuts
Throttle arm and new hole measurement (42mm)
Throttle cable routing
If the throttle cable is routed incorrectly, this can cause the throttle cable outer sheath to foul on the throttle lever arm and hold the throttle open, with the driver NOT being in control.
Please ensure, whilst looking from the front of the kart, that the throttle cable is directed across to the right, under the front of the seat, and up in between the side of the seat and engine. It should not be directed up to the left and around the back of the seat.
See the images below for reference from the online content (24B Sprocket & Chain):
Correct throttle cable routing
Correct throttle cable routing (continued)
We just can't get the throttle spring to hook on. What can we do?
It is important to ensure both ends of the throttle cable outer sheath are seated correctly — one end in the throttle pedal mounting assembly, the other in the throttle cable mounting block.
If you are having trouble hooking the spring into place, it may be necessary to use a pair of side cutters or long nosed pliers to assist with this. You can also use these tools to help bend the end of the spring so that it is more open, to aid with hooking it into position.
We can't get our clutch off. Why? Is that ok?
Sometimes the clutch can be difficult to remove due to heat build-up during use — you may also need to use an impact driver to remove the clutch bolt initially. If the bolt is removed and the clutch doesn't come off, try to shock it by briefly hitting the centre point where the bolt attaches with a hammer, which should cause it to release and be removed. If you are in any doubt about this procedure, you must first contact jake@espireeducation.co.uk.