Carb cleaner, it does the job it's meant to and isn't as harsh and it is exactly what it is meant for.
do a search for tutorials on how to clean the throttle butterfly and body.
A split like that in the tube, its worth replacing but I know they can be expensive from a dealer.....
But you can also use Vulcanising fluid, the glue that you get in bicycle puncture repair kits. Vulcanising fluid actually welds rubber together making it stronger at the point of contact than it was originally.
Clean off any dirt and contaminates using carb cleaner between the split surface.
brush the vulcanising fluid on the inside of the pipe split and then between the split and join them, now for good measure brush it on the outside of the split.
A couple of long cable ties come in handy to keep the split held together at this stage and allow 20 minutes to dry.
Remove the cable ties and now test the rubber tube.
The three ends need to be covered by rubber inspection gloves and elastic bands etc.
Dunk the whole tube into a bucket of water to inspect for any air leaks, just like you would do with an inner tube... If there is any more air bubbles escaping, make a note of where and dry the tube off and repeat the process above...
Tiny splits can be sealed by brushing over the small cracks with the vulcanising fluid and held together until dry.
Dunk it again to make sure you have them all sealed
Your tube will now be stronger in the suspect areas than it was originally
BTW, most pound shops have bicycle repair kits in so not expensive