I'll make this as simple asi can. Ethanol is achohol---achohol attracts water---water creates corrosion---corrosion plugs the small passageways in the carb. Achohol causes the viton tips and/or seats to swell, making them not to seat properly. We have found that using the ultrasound cleaner cleans the passageways in the carbs and the brass jets. Setting valve clearance can be done a variety of ways. For the average mechanic, the 1/4" past TDC works well and it is easy to understand. Is it the most accurate way, no. Setting the valve clearance at XXX number of degrees past TDC (this varies with engine size and manufacturer) is the best way, but 99% of the mechanics or average Joe do not have the tools, time or knowledge to do this.
Finally, for the most part a battery with 225 CCA will turn over a small engine very well. The problem is that as this battery will drain down rapidly, unless the engine is kept in optimum operating condition. The average home owner does not do this. Increasing the CCA allows for a wider range of engine conditions, while also allowing the consumer to start their engine in a wider variety of conditions. On this sire we speak to the average person and our answers shouldn't be taken as the only possible and absolute solution. I have to work on someone else's unit and if it comes back, because I only solved the problem in the short run, I will be out of a job fast. Sometimes this means that it is not the cheapest way or easiest way to do things, but that is what we have to do. I want and need the customer to have confidence in me to come back in the future. Hope this answers you concerns.
Finally, for the most part a battery with 225 CCA will turn over a small engine very well. The problem is that as this battery will drain down rapidly, unless the engine is kept in optimum operating condition. The average home owner does not do this. Increasing the CCA allows for a wider range of engine conditions, while also allowing the consumer to start their engine in a wider variety of conditions. On this sire we speak to the average person and our answers shouldn't be taken as the only possible and absolute solution. I have to work on someone else's unit and if it comes back, because I only solved the problem in the short run, I will be out of a job fast. Sometimes this means that it is not the cheapest way or easiest way to do things, but that is what we have to do. I want and need the customer to have confidence in me to come back in the future. Hope this answers you concerns.