I dried fired my engine to test my Tach out (bout 10-15 seconds). Tach is reading 2000 rpm. This sound like right RPM out of water? Never had a reason to need/know out of water dry readings before.
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I dried fired my engine to test my Tach out (bout 10-15 seconds). Tach is reading 2000 rpm. This sound like right RPM out of water? Never had a reason to need/know out of water dry readings before.
Sounds high to me I would think closer to a 1000 RPM with no load or exhaust pressure.
I wouldn't start it at all without water going to the water pump. It only takes the impeller a short time to burn up without water on it.
What he said.
I know this, but that don't solve my problem.
Maybe you don't have a problem. Tom I don't know squat about these newer motors but I would run it again with water hooked up or better yet in the water and see what it does. Could the CPU be increasing the idle until the motor warms up? Is the tach set to match the number of pulses your motor is putting out?
Is your tach set for the number of cylinders on your engine ? Tach will also only read right with motor in the lake.....the resistance from the water and prop size and pitch governs your rpms. Also is your tach set for two stroke or four stroke ?
You could try putting a timing light to it and compare to see how far off or on it is. Then go from there.
Tom, my 50 Yamaha will go to 2000 when it is cold then after a minute or so will drop down to 1000. Need to hook it to muffs or put in the water to get a true reading. Think your probably ok.
Scrapper, could you explain that, how you tell rpms with a timing light? or anybody?Quote:
Originally Posted by Scrapper
Yep....I don't get it eitherQuote:
Originally Posted by wilbur
Well my timing light also has a digital tach on it. Picked it up at Harber Freight a LONG time ago. Guess I should've been more specific. Sorry about that. It reads off whatever wire you have it attached to. You get a spark and you've made a cycle.
I used it timing a few old mercurys. The "tower of power", had to retard the timing on them due to preignition. Fuel isn't what it used to be.
My motor tach's about 1300 for the fist few seconds, the drops to just below 1000. I try to remember to wait to put it in gear.
Ok. Tach is set on 3 cyl. Will try all stuff mentioned. Called tach manuf. They are sending me some type of filter.
Brought my muffs home so I will use them next round of tach testing.
Will report back. Thanks for the insight.
Tom
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What tach are you using Tom? Outboard tachs are normally set to match the number of pulses coming from the charge coils on the stator. There are a few that go by the number of poles. Just curious.
2 inch GlowShift. They sent me some noise filters. I found one of the filters that fixed my problem. I am in business.
Glowshift tach is selectable 1-10 cylinders.Tach wire was picking rf noise.
Neat little tach.
Mine acts pretty dumb too. Think I'm gonna shoot it and start from scratch.