How much longevity do you have if you float the valves, bind the springs, bend or break a valve. What if the carb is too fat and you wash the cylinder. What do you consider the wrist pin and piston; top end or bottom?
Depending on if it's an interference fit valve. We intentionally float valves on some stock class engines currently.
Binding springs means you purchased the wrong parts, assembled them incorrectly, or did not do sufficient machine work.
Bending or breaking a valve can be caused by using incorrect valve train components. It can also be caused by excessive rpm (ex. throwing a chain,) or simply parts failure.
If the carb is too fat, it needs to go on a diet...or be correctly tuned on a dyno by a competent operator/tuner using an a/f ratio meter.
Washing the cylinder is critical prior to assembly, not after. I prefer to use mineral spirits, followed by hot soapy water, next brake clean, then wipe with marvel mystery oil on a lint free rag. If you wait to wash the cylinder with fuel, you will be unhappy with your results.
The wrist pin and piston are bottom end components as part of the rotating assembly.
In today's society of hyper-political correctness, I would be careful not to discriminate and label... the wrist pin and piston are whatever they "feel" like they belong to (top end or bottom.)
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Oh yea, we really like building the genuine Honda HX390 over the clones of the same platform, and have most of the parts in stock for said build.
For all out power, price, and reliability though, I would consider the MX-based 250 and 450 engines.
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Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
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29 years of service to the karting industry
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