ordered a tiny tach for my Yamaha 64x 760 in my jet boat for a few reasons... diagnostics, hour timing, and just to see what rpm im turning. Has anyone put this on a jet ski before? Just coil the wire around the plug, ground it, and your good to go?
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tiny tach instal?
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JoshKeller
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ive had a couple of the $12 ebay knockoffs and i just stripped off a good bit of bare wire, wrapped it around the top spark plug one time, taped it on, then ran the wire directly to the tach. works fine and is as accurate as the analog one i had on my boat.
Just do as Josh said and wrap a good bit of wire around a plug wire and electrical tape it on. I didn't strip any of my wire and it works fine. I also added about 6' of 14AWG wire to mine to extend it with no issues. Just make sure the wire isn't close to any other electrical parts of your motor or it will give weird readings.
I have a amazon knockoff, and mine shows 2x the rpm's that the factory tach does. I got it for the hour function, not the rpms. I tried adjusting the # of wire wraps around the top plug, but no change. Would stripping the insulation off the cheap tach wire and putting in ON the plug itself correct the issue or not??
JoshKeller
Well-known member
TNtroller said:
mine did the same thing if i wrapped the wire around the plug wire. I simply stripped off 4" of bare wire and looped it around the plug wire and twisted the rest around the tach wire and electrical taped around it. they also have settings to adjust the pulses
Anyone document the process with pictures? 
Mine does that too on a 18hp Nissan. Tried everything LESS the just "looping" it around the plug wire. Hopefully not a DUMBTNtroller said:
question - but did you use a big loop or small loop tight to the wire? I thought I was also getting readings from the other plug wire, as they are darn close to each other as routed.
I looped mine tight around my top cylinder plug probably 4-5 times. Then taped it on real good with electrical tape. Like was already said, you have to set the unit up for the appropriate sparks per revolution of your motor. Otherwise it will give false readings. Also make sure the wire isn't running close to any other electrical components on your motor. Mine ended up giving weird readings because my zip tie broke and the wire was running right next to my power pack. Re-routed the wire to the other side of my motor and fixed the issue.
DaleH said:Mine does that too on a 18hp Nissan. Tried everything LESS the just "looping" it around the plug wire. Hopefully not a DUMBTNtroller said:
I thought I was also getting readings from the other plug wire, as they are darn close to each other as routed.
I wound the tach wire around the plug wire as tight as I could get it and kept it as tight as possible until I had the zip tie snug. I left a bit of a long end on the tach wire after it was wrapped around the plug wire so I could lay it back against the tach wire and secure it under the zip tie.
Got it installed it comes set on 1 spark per rpm which is to much my idle was like 6000 so I put it lower I guess I got it close but I'll need to look up to verify how many sparks per rpm it actually does. Couldn't get it over 3500 rpm something's wrong even if I have the tach wrong after about 3/4 throttle the more gas I give it seems to just loose power.
