One other option for a diesel tach: https://www.tinytach.com/diesel-tinytach <https://www.tinytach.com/diesel-tinytach>
These can be had on Amazon for under $60.00. I just built one into a new engine control panel I made for my LF38; I’ve never had either a tach or gauges on the boat, as it came with the original Yanmar Type A panel with a couple of idiot lights and a horn. I’ll have pix to post this weekend after I (finally) launch… — Fred Fred Street -- Minneapolis S/V Oceanis (1979 C&C Landfall 38) -- on the hard in Bayfield, WI :^( > On Jun 1, 2018, at 10:00 AM, Francois Rivard via CnC-List > <cnc-list@cnc-list.com> wrote: > > Hi Kevin, > > The only way I know of is to use another tach... That doesn't have to be > expensive or complicated. I used my R/C airplanes optical tach to validate > mine and it worked fine. You paint a sliver or white stripe on the shaft / > shine a flashlight on it / point the tach at it. > > They are about 20-30 bucks > > R/C Tachometer: > https://www.amazon.com/Hangar-Micro-Digital-Tachometer-HAN156/dp/B0006N72U2 > <https://www.amazon.com/Hangar-Micro-Digital-Tachometer-HAN156/dp/B0006N72U2> > > Automotive Optical Tachometer: > https://www.amazon.com/Neiko-20713A-Tachometer-Accuracy-Batteries/dp/B000I5LDVC/ref=sr_1_2_sspa?s=industrial&ie=UTF8&qid=1527864869&sr=1-2-spons&keywords=optical+Tachometer&psc=1 > > <https://www.amazon.com/Neiko-20713A-Tachometer-Accuracy-Batteries/dp/B000I5LDVC/ref=sr_1_2_sspa?s=industrial&ie=UTF8&qid=1527864869&sr=1-2-spons&keywords=optical+Tachometer&psc=1> > > Good Luck, > > Francois Rivard > 1990 34+ "Take Five" > Lake Lanier, GA > > > > > > > Good points Francois, I have meant to take a good look at the prop and > probably do need to send it off for reconditioning. > > I know the bottom is a little dirty and so is the prop. But even when > everything was freshly painted I still had this issue. It starts up very > easily which makes me think that I'm running it at a decent load. > > Is there a way to determine the reliability and accuracy of the Tach? > > > On Fri, Jun 1, 2018 at 9:30 AM Francois Rivard <jeanfrancoisriv...@gmail.com > <mailto:jeanfrancoisriv...@gmail.com>> wrote: > Hi Kevin, > > In addition to making sure the transmission is fully engaged (We had that > issue too, for me, it was solved with a simple cable adjustment), it sounds > like you should jump in the water and take a good look at your prop. What you > need to do is grab the blades and wiggle them against the folding axis. So, > not following the folding movement, the other axis -> back and forth. If the > tip moves more than 1/8 - 1/4 inch the hub and blades need a rebuild. > > The Martecs only go so long before needing a rebuild which consists of > reaming the pivot axis hole and installing a larger diameter pivot shaft. It > sounds like a big deal but it's not: Last time I had it done Martec did it > for $80.00 plus shipping. > > The 3GM30F (I have one on my boat) is a small displacement engine (950 CC) > and by diesel standards: A High revver. It needs to cruise between 2800 and > 3000 rpm and should run about 3400 rpm flat out. If it's in good shape and > it can't achieve that something is amiss: Too much pitch on the prop / dirty > and draggy bottom / combination of both. > > When I had my prop redone Martec sold me higher pitch blades saying it would > "Run better" It didn't. All I got was cavitation and vibrations. Going back > to the original blades solved the issue. Yes, the blades with more pitch > were pitted (Obvious sign of cavitation), they looked like they were infested > with little crustaceans that don't exist in a lake. > > When Yanmar says you should run the engine at those RPM they are not kidding. > Prior owners of my boat ran it at low rpm too often and turned the engine > into a "Hard Starter" (What the local mechanics called it) as not enough load > and RPM caused excessive carbon deposits / fouled the injectors / messed-up > the whole thing. it was literally a 5-10 minutes battle to get the engine > running on the first start of the weekend every time we used the boat when we > first got it. > > I "fixed" the issue by running it at prescribed RPM / running it wide open > for at least 10-15 mins every weekend / using Diesel Kleen Power service > injector cleaner. It took over 20 gallons to really make a difference but > now the engine starts within a few seconds every time when cold and > immediately fires-up for the rest of the weekend. > > Good Luck, > > -Francois Rivard > 1990 34+ "Take Five" > Lake Lanier, GA > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray >
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