How do you know if a rectifier is bad on an '88 Force 125 ?

[blmkso]

1st of all , thanks to all that have helped me from this forum. You guys are great. My 88 Force 125 is over-charging( around 16v at higher speeds and 13v at lower) I'm getting this reading from the gauge and the fishfinder. I've read the sticky about changing over to a snowmobile regulator but was wondering how you know when a rectifier is bad. From the little bit I read , the rectifier converts AC to DC but is it also supposed to control how much it converts ? If the rectifier is bad , why not just replace it ? Thanks !

 

[pnwboat]

Re: How do you know if a rectifier is bad on an '88 Force 125 ?

The rectifier on your 1988 125hp Force motor does not regulate the DC output. There is a small voltage drop across the rectifier, however, the DC output of the rectifier is directly proportional to the AC input of the stator. The rectifier/regulators used on later model Force motors does limit the DC output to 14.5 volts.

 

[fucawi]

Re: How do you know if a rectifier is bad on an '88 Force 125 ?

So pnwboat how does that help him test it ??? First disconnect all 4 wires and take your ohm meter. put one lead on red pos and other on an ac input wire ..read and swop over the connections ..should show infinity one way and low ohms the other . repeat this for the other ac wire . Then connect one side of meter to case ( neg ) and repeat with the ac wires ..each should show high and low if you get low low short and high high open circuit ...you can get these things at radio shack for a few dollars known as a bridge rectifier get rating say 20 A 50 v

 

[RRitt]

Re: How do you know if a rectifier is bad on an '88 Force 125 ?

1st of all , thanks to all that have helped me from this forum. You guys are great. My 88 Force 125 is over-charging( around 16v at higher speeds and 13v at lower) I'm getting this reading from the gauge and the fishfinder. I've read the sticky about changing over to a snowmobile regulator but was wondering how you know when a rectifier is bad. From the little bit I read , the rectifier converts AC to DC but is it also supposed to control how much it converts ? If the rectifier is bad , why not just replace it ? Thanks !

if one of the posts is broken off or if one of the wires is cut then your rectifier may be broken. Otherwise it is probably working just fine. Rectifiers are virtually indestructible.

1988 engines were pre-digital and did not have expensive electronics to protect. The battery will regulate your system down to a voltage level that is safe for most devices. Do not disconnect battery with engine running as your voltage will spike and can damage you CDI or other electronics. The overvoltage may be annoying but is a trade off between reliability of engine starts against durability of battery. Rectifiers never break unless you beat them with a hammer. Regulators break all the time. If you have a rectfier your batteries won't last as long but you'll never have a dead battery after leaving home. If you have a regulator then your digital stuff is gets better protection from brain farts (aka disconnecting battery wire with engine running) and your ski-boat battery may last longer.

The fact that you can get a DC voltage reading above the battery indicates that your rectifier is working. If it was broken then it would put out AC voltage which does not show on a DC meter.

 

[blmkso]

Re: How do you know if a rectifier is bad on an '88 Force 125 ?

Thanks , you have put my mind at ease.