I have noticed no cracks in the gel coat yet, but I also reinforced the tunnel area fore to aft, and also the transom. Seeing it up on step, the sponsons tapping the water and the engine note! Awesome! I had to change the EXP quite a bit, so it wasn't so twitchy at speed. It's a little light in the front so we added some weight to bring the nose down during flight. It's a 70' Viking, so the waves are quite large. When I go out fishing on my cousins boat, I jump the wake with it. Now I use it every weekend that I have free. I also installed the Redline Performance modded 257 carb, and Warehouse Hobbies aluminum velocity stack.

That would have more than likely come loose on the first outing.

When installing the seals, is when I noticed how loose the clutch screw was. 003 composite gasket, stainless screw and bolt set, and zero drag seals. Before I went out on the water, I went through Zac at American RC Boats, and bought the mid mod jug, lightened piston. Your will probably save some money and frustration in the process. If you just ship your motor to someone who knows their craft (M D, SS, Toxic, Butch, or one of several others) you will likely end up with a more potent motor that is done right and will likely be as easy to start as your stocker. Also - many 'modifiers' out there doing less than admirable work - particularly those who just offer parts and not RTR motors. Unless you know what you are doing you might very well damage your motor rather than improve the performance (like installing your lightened piston back to front). A sheared key will also be one of the hardest 'non starting' symptoms to diagnose and usually the last. Shear your key and you will never get her started. For one thing the stock keys are easy enough to shear - offset timing is even less strength. The flywheel key is not a modification I would consider (or recommend) regardless of modificatiosn done. Not all modifications will lead you to increased performance.

I would consider having fun with the motor in stock form and gain some familiarity with tuning it before you set out to modify it. Sounding like your having trouble with a stock setup motor.

Blackjack rc boat 55