Hi, I am new to the mini bike world I just bought a used murray track 2 bike off of craigslist yesterday, and it needs a little work I was curious if it would easier to just put a new engine or work on the one that's on it now which is a 3.5 hp Tecumseh. I know it needs a carb rebuild for sure but it also looks like there may be some linkage springs missing and also the spark plug cap is missing . The guy I got it from just has the wire wrapped around the plug, also missing the top nut on the forks any help will be greatly appreciated.