1985 Johnson 150. Tach and alarm question

[maverick974]

The boat I just purchased has a 150 Johnson VRO. I took it out for the first time today and it ran great. It's on a 17.5 foot fish and ski. Darn near pushes the boat right out of the water on the hole shot.
Anyway, I was very pleased with how it ran but there were some concerns that perhaps you guys can help me out with.
I don't know if it's propped correctly. I got 2 props with the boat. One is a 17p and the other is a 24p. It currently has the 17 on it and that prop pulls so hard it shoves you back in your seat but I'm not sure if I'm over revving and WOT. That's where the tach comes in to play. It doesn't work so what should I look for first to get the tach working?
The other issues I had is a buzzer. The oil injection system has been disconnected so I'm assuming the buzzer was an over heat alarm. I got the boat off the trailer and idled past the no wake buoys and the alarm turn on so I shut the engine off. I waited a minute or so and then started the engine again. It sounded good so I got up on plane and then the alarm turned on again and the engine quit. I started the engine again and it ran fine the rest of the day. Stuck T-stat?????? Water was coming out of the pee hole the entire time. Does that water bypass the T-Stat?????
The buzzer seemed to be coming from the shifter.
What is that buzzer and what should I check?

Long story short?

Problem one is the Tach. Problem two is what causes that alarm to buzz?

[jere1972]

Could be bad tach! could be bad rec/reg, bad stator, broken or disconnected wire, (grey I believe) tach works of the charging system, go to CDI Ignitions Web site search around for there trouble shooting guides, as for the alarm, on the newer models there is a high temp alarm steady noise, and fuel/oil alarm chirpping noise I believe, I would suspect temp you can disconnect your temp switch should be 2 while alarm sounds see if that kills it if so it's high temp! I believe yes you can be pissing water and still over heat the pissing water is just an indicator your pumping water, if one of the 2 T-Stats fails to open there will be an overheat situation on the side that fails, did you pull the cover and feel the port and starboard heads? as far as rpm I would say you want to be able to hit @ least 5600-5700 rpm, if your hitting 5900-6000 I'd go with a deep pitch I think the rule is 200 rpm per inch, if running a 17 and hitting 6000 WOT running a 24 will drop you 1200 rpm, all you can do is try the 24, once your tach is working, if you above 5600 WOT I think your good with the 24

[maverick974]

Thanks for the info on the tach. It's probably a bad tach or something simple like the wire. I'll check the CDI Ignitions website.
The alarm was a steady buzz and the way it turned off, I suspected a stuck T-stat. Once the alarm stopped, it didn't come back on all day. I'll check both tomorrow.
With no tach, I can't say if it would over rev at WOT but because of the bad tach, I only went WOT once just to see what it would do. (hey, first time with this boat on the water. I had to do it once.) I didn't go over 3/4 throttle after that. Even at WOT, the engine sounded AWESOME. Like I always thought an outboard should. I was very happy with it.
I'll try the 24p prop next time I take the boat out but without a tach, I'm only guessing.

[maverick974]

Well, I've taken the boat out a couple times now and I'm very happy with it. Now to find the right prop and to do that, I need the tach working.
The charging system is working normally so I've ruled that out. Next I'm trying to check the wire from the rectifier to the tach to make sure it's not cracked or something. From what I've found on here the wire should be solid grey. Is that correct?
Also, it's beginning to look like the tach is bad unless it's the wire. So I'm looking at tachometers and I have a few questions. I've done some research on here and it looks like I need to get a 12 pole tach. Will this tach work?

http://greatlakesskipper.com/product...ter-gauge.html

[jere1972]

you are correct, 12 poles, usually 6p setting on the tach for johnson/evinrude 70hp or greater!

[maverick974]

That's good to know because I already ordered it. lol.