dgav407

chipracer, the engines will run slightly hotter in the 4WD off and on-road cars - the engines work harder due to the extra weight and the inefficient drivetrain (compared to 2WD). For example my Baja 1000 Evo 2 ready to go weighs 27 pounds and my all-alloy Harm Bx1 buggy significantly less at 23 pounds!!

The plastics gears (24 and 25 teeth) can suffer from the heat generated by the engine - although in 16 months of racing/bashing two MCD cars I have not melted any of the black plastics gears - the only damage is from small stones/rocks. One tip I can suggest with the plastic gears is from new and when alternative or replacement gears are installed is to bed them in by driving the car slowly for the first few minutes.

I installed the KCR alloy gear plates in my cars and this helps with cooling but to be honest the steel gears are the only option part that is needed. The cars being raced off-road successfully here in the UK are just using the steel gears - no expensive alloy gear plates. These cars are being raced with expensive full-race engines (oddified, Alro etc) and I don't think the owners would risk them if there was the slightest chance of the engines overheating and seizing....

As for cutting out the windows - I initially only cut out one side window for access to the kill switch and pull start plus a small hole for the standard CY can exhaust. I could not understand why the engine ran so hot and continually needed the carb to be adjusted. There was always a noticable drop in performance towards the end of 15/20 minute final at race meetings as the engine slowly cooked!! Only as a result of cutting out the side windows (and drilling holes in the front window) and changing to a Castor based oil have I seen a drop in engine temperature and consistent engine performance.

At the very least you should have access to the kill switch and pull start without the need to remove the bodyshell.

Clive