Hi I was wondering if anyone with experience with nitros could help. I recently bought a hpi nitro truck and withing about 2 runs the pull start broke so I ordered a rotostart kit, what I've found though is that the engine sometimes locks up around tdc and to loosen it I have to use a big straight screwdriver to turn the engine over. I'm guessing this isn't normal.

I acn still get the engine to start but it takes a bit of messing about. Any tips on what I can do to sort this?

Thanks

If the engine is in new condition they can be pretty tight.You can warm it up with a hair dryer before trying to start.Rotostart works better then a rope for sure.Put your finger over the carb barrel,it acts like a choke.Just for a few seconds while trying to start it.

It's not been broke in yet. Read the break-in thread in the sticky thread above. Take your time. It's important. Have fun!

Becuse the piston has no piston rings you need to get the piston in perfect shape with the sleeve. The sleeve will be cooled by the fuel on the lowest part of the sleeve and hot on the highest part of the sleeve. With the temperature expansion the sleeve will become straight. and then the piston needs to be polished to the sleeve zo start very carefull!