1994 90hp Force No Spark

[seagull369]

Im getting no spark out of my 1994 3 cyl force outboard. I fear it might be the **** switch box again. I already had the box replaced a couple of years ago (along w/ stator) due to a no spark situation. The name on the replacement box wasnt Force (or Mercury, since the motor is made by them) but rather a company called CDI Electronics.<br /><br />What kills me is that the boat ran fine until I brought it to the welder, who welded my busted skeg welded back on (lower unit wasnt seperated). I talked to the welder about my suspicion and he said it wasnt possible since current was only traveling between the short distance between the anode/ cathode which were both located on the lower skeg area. I myself am not so sure.<br /><br />Regardless of that, I have a boat that won't start now. I've heard that the switchbox cant really be checked w/out special meters which would set me back more than if I were to take it to a shop. My manual tells me I can take ohmic values for various colored wires, which might be indicate a problem. It also, of course, suggests I check all ground connections. Someone recommended that I disconnect the black/yellow kill wire and see if it sparks then, to see if the kill switch in the ignition is the cause (there is no lanyard switch on the boat). <br /><br />Any suggestions on how else i might test the switchbox to see if its working? Any other components I might want to check as well? I was planning on checking the alternator & rectifier. Anybody have any opinions on the welding scenario, and or the reliability of CDI electronics switchboxes vs OEM? Any input would be greatly appreciated. Ken

 

[wilde1j]

Re: 1994 90hp Force No Spark

Arc and heliarc welders generate intense EMI, RFI and fields which conceivably damage a switch box. It's almost like putting electronics in the path of a lightning storm. If the welding didn't get a good ground (i.e. unpainted bare metal), the situation is further agravated. If the motor was running fine before the welding, my money would be on the switch box.<br /><br />I don't have any Force specific info, so can't help with confirming failure. You might check to see if Sierra Marina or one of the other third party parts outfits have the right part. It would save you some $.

 

[SB]

Re: 1994 90hp Force No Spark

CDI guarantees their switchboxes for 2 years. The date is stamped on the back of the box. I have a Sport Jet 90, essentially the same powerhead as yours, and my CDI switchbox went bad after one year. I just called them and explained the problem and they sent me a new one. After I installed it I sent back the old one. They even gave me a UPS prepaid return label, so it didn't cost me anything. They took my credit card number but never charged me. They were very easy to deal with, I even talked to the owner about another electical problem.<br /><br />Check out their web site, www.rapair.com.<br /><br />Scott

 

[alounsbury]

Re: 1994 90hp Force No Spark

I have a 1993 force 90. To check the switchbox you can use a regular DVM plus a simple peak voltage adapter. To make one all you need is a diode (IN4005, Radio Shack 275-1104 works) with a rating of 400 Volts and a capacitor .1 ufd rated at 400V. Then connect as shown at http://www.elantec.com/pages/apppdf/d40960.pdf This works great and then you can check your stator voltage and trigger voltages while cranking. I would suspect the stator took a hit and cannot explain relationship to welding.<br /><br />Switchbox voltages listed at http://outboardparts.com/mercury/troubleshooting/troubleshooting11.htm <br /><br />Good luck.

 

[seagull369]

Re: 1994 90hp Force No Spark

Thanks for your help, guys. I did manage to take some reading that my repair manual suggested. Ohm values for the trigger checked out. Low & high speed stator Vacout was low, as was their ohmic values. Switch box bias test showed VDC to be at 2V. Book said that was ok, but since trigger resistance test checked out, I should replace switchbox.<br /><br />I did learn recently myself that there's a 2yr warranty with CDI's boxes. Unfortunatley, the last one was replaced 4 yrs ago. I also did stumble across Seliers web page on my own, and find out they do sell them. Price $180.<br /><br />Guess I should just go out and buy it. Even if that turns out not to be the problem at least I have a spare if the current one decides to go in the future.

 

[seagull369]

Re: 1994 90hp Force No Spark

Forgot to mention... Al, I went to the PEAK VOLTAGE ADAPTER AND RESISTANCE CHART link your provided to me. Unfortunately, I had a little difficulty deciphering the resistance (R)values under the "stator" column from the '94 UP 75/90/65 Jet 3cyl) row. R values I need are for the CDI/Rapair stator, but I cannot figure out what that box is saying. Box reads something like this: 398-8778* 398-9710* 174-8778K1(a) 174-9710K1(a). What does "K1(a)" mean? Do you have any idea what therye talking about? I also can't distinguish OEM vals from Rapair vals. I followed the asterisks to the last page, but it didnt really provide much insight. Can you help? Thanks for posting the link, and the peak reading adaptor as well. Great resources! Ken

 

[kenimpzoom]

Re: 1994 90hp Force No Spark

Both me and a buddy have our Sport Jet 90s with no spark. Any more info on this subject.<br /><br />Also, we cant figure out the readings either on that chart.<br /><br />Kenimpzoom

 

[alounsbury]

Re: 1994 90hp Force No Spark

Ahhhh yes - those nasty non-english readings. Here is the layman version - I think?<br /><br />The CD Ignition column actually lists the part numbers of the switchbox, with the OEM Number underlined. Since I have a 90HP, 93 Force my OEM # is 332-7778A which is in the '88UP 3 Cyl row. For Force, your OEM numbers can be found at http://www.mercurypartsexpress.com/PartsExpress/HomePage/homepage.asp Right below that is the CDI replacement number. <br /><br />Next column over is the Stator OEM and CDI numbers. OEM is underlined which for me is 398-8778. <br /><br />The next column over is the resistance values for the trigger windings. As the values for the OEM and CDI are different - both are listed. So on the trigger in my case for OEM (underlined values) the resistance should be between 750 and 1400 ohms. <br /><br />The next column over is stator, which in my case has three coils, charging coil, low speed (LS) winding and high speed (HS) winding. Not sure why they mention charging coil, since resistance value for that is not listed. Anyways in my case the information is not complete in this column with no values listed for the OEM. However from the Seloc manual they should be between 5500 to 6200 ohms for the LS winding and 90 to 140 on the high speed winding. In my case the low speed winding was shorted causing me stalling at 3000 RPM.<br /><br />The next column is Trigger voltage while cranking with a peak reading adapter. The DC peak voltage should measure >4 volts on each trigger.<br /><br />The next column is the stator voltages which in my case is HS (high speed) winding should be greater than 20 Volts peak DC and on the LS winding greater than 180 Volts peak DC. This was my problem - actually the voltage would dip on accerleration and then stall.<br /><br />Last column is the Ign coil peak DC voltage. This is usually easier to measure at the switchbox rather than the coil. Basically you should see greater than 150 volts peak DC while cranking on each coil. No power here = no spark.<br /><br />Hope that helps. I just received my new stator from Boatfix.com - great price and service which is a treat for us Canadians.<br /><br />Al

 

[seagull369]

Re: 1994 90hp Force No Spark

I talked to the repair guy I brought my boat to. He told me that the switch box has indeed blown. <br />In addition to replacing the box, he recommended I change the (3) coils (one for ea. cyl) on the motor as well, even though the ohm test checked out ok on them. <br /><br />The reason for the coil replacement, he told me, is sometimes even though a coil tests out all right, it can still be defective esp. when a switchbox repeatedly blows like mine does (this is considering of course the stator checks out ok, which he said it did). Specifically he mentioned something about a defective coil generating a feedback condition back to the box which can damge to it. I never heard of such a thing, but he claimed in one specific job he had, the switch box was replaced more than several times until the coils were changed and after that everything was fine.<br /><br />Anybody ever hear of a coil causing problems with a switch box, even when its ohm value checks out? Anybody know of a inexpensive place to find all these parts? I've checked out Seiler Marine and am about to look up Boatfix.com. <br /><br />Thanks again everone for your help!

 

[SB]

Re: 1994 90hp Force No Spark

I never heard of a functioning coil destroying a switch box but that doesn't mean it can't be true. <br /><br />The best prices for parts that I have found is at DougRussell.com

 

[lonewolf5347]

Re: 1994 90hp Force No Spark

I HAVE A 1994 120 FORCE @ OVER THE YEARS HAVE GONE THREW 3 STATOR @ SWITCHBOXES.TWO WERE O.E.M. PARTS THE LAST ONE I INSTALLED WAS CDI PARTS @ HAVE NO PROBLEM WITH THIS ONE SO FAR.THE COILS HAVE NOT BEEN REPLACE EVER.COILS CAN BLOW A SWITCH BOX IF NOT GROUND WHEN DOING A COMPRESSION TEST WERE SPARK PLUG WIRES ARE REMOVED FROM SPARK PLUGS.A WEAK BRATTERY WITH A DEAD CELL CAN BLOW A STATOR @ SWITCHBOX.ALSO DISCONECTING A BATTERY + TO SEE IF ENGINE IS CHARGEING,RUNNING ON A CAR BATTERY,TO REPLACE A STATOR WITH THE RIGHT TOOLS ABOUT A 20 MIN. JOB IF YOU NEED PARTS TRY www.seilermarine.com MIKE HAS GREAT PRICES ON STATORS AND SWITCH BOXES.