Well my coil tests out with a digital meter.

The rectifier does not at all.
Not with my meter, not even with a high dollar Fluke.
I'm thinking it should read the resistance at the 200 setting.
BUT IT DOES NOT.

I do get a reading with an analog meter though.
I checked it with 2 different ones of the same brand.

Both read no higher than 3 ohm resistance on any test.
Should read 5 ~15 ohm for my KFX450R


I think the rectifier is bad, but don't know how it's related to my issues really.

Other than over or undercharging the battery... what would the other symtoms be?
This is a fuel injected bike if it matters.

Could it cause a miss and make it stall very easily and not seem to affect the battery too much?


I guess I just don't fully understand them all that well. I understand that they convert AC to DC... and I know the regulator part regulates the voltage...

I just don't know the rest.

Like I don't think it is undercharging the system, or not all the time anyways... but might be overcharging... but I would think that would make things better instead of worse... like a hotter spark, etc..

What gives with all this?
I need help.

 

A rectifier is diode array kinda like a one way valve. Will pass current 1 way and block it the other. There should be a diode function on your meter. It will read about 700-800 ohms 1 way and infinate the other.

 

OK... that's helpful... thanks a million.

Now I'm getting a reading with the digital.
I was getting it lastnight this way, but I wasn't understanding it... I do now though.

Reading one way, infinate the other... like you said.

One reading is 713... the others are in the 500 & 600 ranges.

Trouble is, I don't know what that means.
My service manual gives no detail on testing this way.

It only says to set the meter to the 1k ohm range and the readings should be 0 or 5 ~15 depending on where the probes are placed. I get 3 ohms max on highest one.

I've gotten that reading with 2 analog meters of the same brand.

If correct, that would mean the resistance is too low?
So the current would be too high?

 

Don't know about your particular model but there should be a total of 5 connections 3 AC inputs, positive output & neg output (ground). Ground may be the case mounting stud. Many newer machines have an integrated rectifier / regulator that makes it more difficult to test. What kind of voltage do you get across the batt @ say 3000 rpms (about quarter throttle) should be in the neighborhood of 14-14.5 volts.

 

Yeah, I have the service manual and the testing instructions.

The test is resistance across the connectors.
I only get readings with an analog meter.
Should be 5~15... I get 3.

 

Would think then the assembly is blown & time for a new one. think they are like 110$.

 

I think so too... I'm just not 100%.
I don't get it not reading on a digital... and in a way that makes me not trust a reading from just one brand of analog meter.

But I'm thinking it is bad... low resistance.

I'm just not making much sense yet of HOW that's causing problems.

I'm going to mount it back and do some output testing on it... and test some other items too while the electrical is all in-tact...

But I think it's bad and if it is, it won't cost me a dime.
It's under warrany.
I understand that fits too because they typically fail early on or last a long time.

I just wanted to know myself what the problem is for my own piece of mind before I haul it in for a warranty claim.

 

OK... an update on this...

Now I'm getting a reading with my digital meter.

It reads only on the 20M ohm setting... WTF?

Reads different cold than hot...
Higher numbers cold, lower numbers right after use.
I can also get readings at 200K and 20K when hot.

Voltage at the battery seems to hang around 14v though when running.
Then 13v when off... and trickles down from there.

I doesn't seem to increase in volts when I increase the RPM... manual says it should.
Like 14.0v ~ 14.5v... but I may not be revving high enough (?)

I thought something like this was either gone or not.
Can it be on the fritz?


I wish I had tried the diode test function while I was at checking it after running.
I just didn't think about it.

 

Duster,

14 volts on the battery terminals is fine. That says the charging system is working.

Lets step back and look at the big picture for a moment. What exactly is the problem you are trying to solve?

 

I have a miss that I have been trying to locate the culprit of... and the dang thing is so weak off the bottom it's a stall queen.


The air filter is still clean... too new to be dirty. I can hear the fuel pump prime up before a start. The fuel injector is clean and tests out for resistance. TPS is set right and tests out. The coil, wire and plug are good.

Just working my way back....