Tach problem

dano7331

Cadet
Joined
Apr 28, 2003
Messages
6
Hi all, I'm wondering if anyone can help me with this. My tach seems to be working fine for about 3 - 4 minutes then it just quits indicating. Do you think it's just a bad tach? My boat is an 87 Sport Craft with an OMC 115 Sea Drive, all of the instrumentation is the original equipment from what I understand. - Thanks, Danny
 

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: Tach problem

iboats sez howdy Danny,<br />It could be your tach, a loose connection or the rectifier could be headin' south. When the tach quits working and the engine is still running, put a volt meter on your battery and see if it's charging or not (fast idle, 12-1500rpms). If it ain't, it's the rectifier. If it iz, look somewhere else.<br /><br />g'luck & c/6<br /><br />Hooty
 

RKwood

Seaman Apprentice
Joined
Jan 10, 2003
Messages
49
Re: Tach problem

I also have a 1.6l (115) Sea Drive, twins actually.<br /><br />I had a bunch a problems last year, including intermittent tach operation on one, and battery on that side not charging. Minor problems compared to a cylinder with low compression.<br /><br />Before we go on, I am by no means an expert, but have learned a great deal through religous reading of this board, and my manual.<br /><br />Anyway I'd first check wiring, verify it's clean and tight espcially wire on junction block at starboard rear of the motor. Next,I'd verify if battery was charging. If battery is charging I'd then suspect bad tach and or wiring. BTW had any overheats lately? (overheat could fry voltage regualtor)<br /><br />I am replacing the voltage regulator on my starboard and noticed the voltage regulator had been replaced on the port by previous owner (coincidence?)<br /><br />Regardless of what you find, I highly recommend getting the OMC Sea Drive manual. It has info in it you wont find anywhere else. <br /><br />FYI, if you need to replace voltage regulator, you'll have to pull the flywheel (what fun!)<br /><br />RK
 

dano7331

Cadet
Joined
Apr 28, 2003
Messages
6
Re: Tach problem

hey thanks folks, I haven't checked the charging yet but I've been working on the boat for the past couple of months and think my wiring is in pretty good shape. Everything I've read so far indicates that my rectifier / regulator is on it's way out. Don't know if this thing has ever had an over heat conditition but nothing in the way it runs or looks indicates it had. Although I haven't had a chance to get it to the water yet, I have run it as needed in the yard with a garden hose and even after several minutes of running the cylinder heads are only shightly warm so I think the cooling system is functioning ok. - Thanks for your help. I can see I'll be spending a lot of time here on this forum :)
 

dano7331

Cadet
Joined
Apr 28, 2003
Messages
6
Re: Tach problem

well, I found a used rectifier / regulator and replaced mine, just thought I'd let you know all is well - Thanks again
 

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: Tach problem

Por nada, Dano.<br /><br />c/6<br /><br />Hooty
 

sparkroost

Petty Officer 1st Class
Joined
Mar 23, 2003
Messages
312
Re: Tach problem

I really don't mean to ask a stupid question... but here goes... why would tach operation have anything to do with the rectifier? The tach lead goes directly to the stator winding, on the AC side of the rectifier.
 

dano7331

Cadet
Joined
Apr 28, 2003
Messages
6
Re: Tach problem

The tach wire on mine goes to a terminal block as does the wires from the rectifier / regulator.
 

Bradster941

Petty Officer 1st Class
Joined
Mar 4, 2003
Messages
203
Re: Tach problem

For what it's worth on rec/regulators, this may help, and save you big $$$<br />-=-=-=-=-=-=-=-=-=-=- :) -=-=-=-=-=-=-=-=-=-=-<br /><br />Bradster941 <br />First Mate <br />Member # 19948 <br /><br /> posted May 05, 2003 03:33 PM <br />--------------------------------------------------------------------------------<br />H2O Rectifier Regulator <br />1987 OMC 115 with water cooled rectifier / regulator combo does have a/c input, no d/c output. <br />Is there any reason I can’t go to the side mount air cooled rectifier and can I do away with the regulator as mentioned in other post? Stator is 10 amps and still good.<br /><br />Thanks, Bradster… <br /><br />--------------------<br />If your too busy to go fishing,<br />Your just too busy.<br /><br />--------------------------------------------------------------------------------<br />Posts: 14 | From: Florida | Registered: Mar 2003 | IP: Logged <br /> <br />Joe Reeves <br />OMC Guru <br />Member # 6826 <br /><br /> posted May 05, 2003 03:40 PM <br />--------------------------------------------------------------------------------<br />Brad..... You may change over to the smaller three (3) wire rectifier on that model with complete ease of mind.<br /><br />--------------------<br />Joe (30+ Years With OMC)<br /><br />--------------------------------------------------------------------------------<br />Posts: 873 | From: Central West Florida | Registered: Feb 2002 | IP: Logged <br /> <br />Bradster941 <br />First Mate <br />Member # 19948 <br /><br /> posted May 05, 2003 03:47 PM <br />--------------------------------------------------------------------------------<br />Thanks Joe, the price differance is increadible. But should I worry not about the regulator?<br /><br />Tks again, Brad.<br /><br />--------------------<br />If your too busy to go fishing,<br />Your just too busy.<br /><br />--------------------------------------------------------------------------------<br />Posts: 14 | From: Florida | Registered: Mar 2003 | IP: Logged <br /> <br />Joe Reeves <br />OMC Guru <br />Member # 6826 <br /><br /> posted May 05, 2003 04:00 PM <br />--------------------------------------------------------------------------------<br />Brad.... With a small 10amp alternator and no doubt P/T/T, it's very unlikely that you'll ever need to worry about an overcharged battery. Install a voltage gauge to ease your mind. If the voltage ever starts to climb over 14.5 volts, turn on some electrical equipment. Cut and get rid of the wires associated with the water cooled job to eliminate any possible problems.<br /><br />--------------------<br />Joe (30+ Years With OMC)<br /><br />--------------------------------------------------------------------------------<br />Posts: 873 | From: Central West Florida | Registered: Feb 2002 | IP: Logged <br /> <br />Bradster941 <br />First Mate <br />Member # 19948 <br /><br /> posted May 05, 2003 04:47 PM <br />--------------------------------------------------------------------------------<br />Thought as much Joe, and thanks.<br />I’m not to proud to ask 4 a second opinion. <br /><br />Thanks again. Bradster…<br /> <br /> :D
 
Top