I've used the FloScan meters in my last two boats. (17 years) My experience has been exactly one time, one meter stopped working right after a filter change. Blowing back thru the sensor fixed the problem. I'm guessing it was a small piece of crud that got by me somehow. One failure in 17 years is not what I consider trouble prone. (avg 100 hours per year on the gas boat 200+ on the diesel) On my gas boat I'd fill with fuel and know within a gallon, how much it will take when buying 100-120 gallons. With my current diesel boat, (120 Lehman) I'm off by less than a gallon in 300 gallons. The accuracy is very good in my estimation. I'm told almost every time I talk about it, that Lehman's return so little fuel that they only have one sensor to measure flow from the tank. The recommended FloScan for my engine, vintage 1980, has a supply and return sensor. There is a different part number for a FloScan for the earlier Lehmans, maybe they only have one sensor. I can only tell you what they recommended for mine. I believe, and I saw it several times on the gas boat, that with the flow meter you can see when something is wrong since you know what you should be burning at any given RPM. If the rubbing block on the points was wearing you could see fuel usage increase for a given RPM. (Yes 1966 CC had points until you changed them to electronic ignition) If you use a measured bucket to find your GPH and something changes your fuel usage you will not know about it until you fuel up, run the numbers and see a problem. I fuel twice a year, could there be a problem in between that I don't know about? I know that when my engine is not fully warmed up, I can see the difference in fuel used. Even though the water temp gauge reads 180, for the first 15-20 minutes I use more fuel. After that, it settles in and doesn't change until the throttle does. My gauge fits in the same hole as the Tach did. It has a tach, total hours, and fuel used (until reset). Reasonable mechanical skills will allow you to install it yourself without problem. As mentioned, they are in the $800 range for the complete setup, depending on what discounts you can find. Once you put that into perspective on how much you spend on other things it may or may not make sense for you. Ken Looking for recommendations for a fuel flow meter for the single 120 Lehman on our MT34. I am not looking for anything that needs to integrate to my systems or run on my computer. Just a system that will show me the fuel flow under whatever RPMs we are running. Simple is better. Thanks, Chuck **************New year...new news. Be the first to know what is making headlines. (http://www.aol.com/?ncid=emlcntaolcom00000026)