2000 Yamaha Big Bear 400

[Gwbarm]

Finally getting around to the Yamaha Big Bear that followed me home in August. It is a mess. I got it off of marketplace, the add stated " runs like nothing is wrong the only thing that's wrong is it needs a new wiring harness". So iv been looking for a new wiring harness although it came with a wiring harness that was out of the bike, so I assumed he had ripped it out. All the plastics were off and no screws or bolts to reinstall but they were in good shape. The coil, voltage regulator and starter solenoid was missing but came with new one. So I go out expecting to start installing the wiring harness and find out its still in tact with these parts missing. The first thing I found was the engine was stuck and there was no spark plug in it. I noticed when I bought it that the pull starter wouldn't rotate the engine but he assured me the engine wasn't stuck that there was something wrong with the pull starter, I was skeptical but took him at his word. I didn't check it that closely because I was really just buying it for the tires and wheels they were worth twice what I paid for the bike. Im a little new at buying on marketplace and am just angry that someone would lie like that, now I don't know if anything is really wrong with the wiring harness, im probably too trusting I usually trust people until they give me a reason not too. I would have bought it anyway, if I go to the trouble of hooking up my trailer and wench and driving there its coming home with me, long as its a Honda or Yamaha I can fix it. It took PB Blaster about 24 hr and I got the engine freed up, and it has good compression, using ye ole thumb over the hole test, and the pull starter works fine Thats enough of that, now for my real question, before I go to the trouble of chasing the wiring problem down I would like to see if the engine is ok , is there anyway to feed voltage directly into the cdi to make it spark. 

[Mech]

Most yamaha seem to have a lot of wires going into their cdi..  Perhaps just drape the wiring over the bike and connect it up and see what you find.... If it's a wiring problem it should be easy to find, it's either going to be a short, which needs chafed or melted wires and so can be seen, or a broken wire, which mostly happen at the ends of the wires where they connect.. or occasionaly up near the steering head. The steering head breaks are the hard ones to find..

[Tiha]

HaHa, I too feel your pain. Did the same thing on a 2001 kodiak. 

Guys said it had no spark. Tweekers tore it apart and I got most of it in boxes. 

Turns out it has spark but the rear end was locked up. LOL 

Anyway, I already had decided I was going to fix it no matter what so I started putting it together figuring I would troubleshoot when I get to a problem. 

If you can get the wiring diagram (I cannot access them yet) there might be a way to hot wire it. Or at least take resistance readings and see if anything is out of spec. 

Or just keep putting it together.

[Gwbarm]

Thanks guys for the quick response. Iv been checking the existing wiring harness and it seems to all be intact did not notice any problems except for the missing parts the coil that came with it  looked like it had never been on a bike was bad, primary resistance was good no resistance whatsoever on the secondary even took the wire and cap off still nothing. The key is missing have to get a new switch and all the other parts I mentioned earlier. You are right Mech about the CDI it like the wire hub central all the wires go there with 3 big plugs. I was thinking the red and white was hot and I might be able to feed voltage there directly to see if it would spark but was not sure if it needed 12 volts there or lower, the service manual didn't really say or I missed it, it doesn't really tell you a check for CDI it has you run all these other tests and if they pass and still no spark replace the CDI. I think I will take your advise go ahead and hook everything else back up and then start looking for the problem. 

[Gwbarm]

I got everything hooked back up except lights, plastics still off, put a new keyswitch, solenoid, coil, plugged every thing where it needs to go and put battery to it. I got a green neutral light, but no rotation with switch. Starter will turn over when I jump the solenoid, so I have some more wire chasing to do, hadn't checked for spark yet, I figured i need to get it rotating by pushing the button before I do that.

[Mech]

You could have a little preview peek using the pull start.. 

[Tiha]

So just thinking outside the box. Does the CDI look new? 

 

I have read over and over about generic CDI boxes off ebay and amazon that will not allow the starter to crank. 

[Gwbarm]

 I haven't heard that It does not look new, I have been looking for a generic one and haven't been able to find one to fit the 2000 big bear 400 there is one to fit the 2000 Kodiak but haven't found one for Big Bear. I really suspect its bad 

[Mech]

Tiha, a lot of yamahas feed a voltage into the cdi while the starter is being operated, it's to make them start easier. That wire branches off the starter wire. Some of the models though, instead of branching off from the starter wire have a feed wire from the cdi going to the start button. On those models the cdi notices the voltage drop when the star button is pushed and causes the same easier starting.

If your bike needs that second type of cdi with the starter voltage going through it, and you fit one of the other model, or a cdi that doesn't have that power going through it, then you will get a no starter situation.

You need to refer to a service manual and check the bikes wiring before buying a cdi for a yamaha.

[Gwbarm]

I tried it no spark, last time I tried it just to see if the starter works, I didn't have a coil yet, installed the coil today plugged in the wire and right next to the coil wire was a black wire that looks like it went to ground not enough wire to go anywhere else so I put it under the nut that holds the coil on. I powered it back up and the fan came on so I figured this was the fan ground. Didn't really want the fan running now so took it back off, so there's a short somewhere there. I do hear a very minute click at the solenoid when I turn the key on so I think power is getting there. Just starting to check start switch circuit to see if it is good and started raining again. Pick back up tomorrow.

[Tiha]

20 hours ago, Mech said:

Tiha, a lot of yamahas feed a voltage into the cdi while the starter is being operated, it's to make them start easier. That wire branches off the starter wire. Some of the models though, instead of branching off from the starter wire have a feed wire from the cdi going to the start button. On those models the cdi notices the voltage drop when the star button is pushed and causes the same easier starting.

If your bike needs that second type of cdi with the starter voltage going through it, and you fit one of the other model, or a cdi that doesn't have that power going through it, then you will get a no starter situation.

You need to refer to a service manual and check the bikes wiring before buying a cdi for a yamaha.

And that may very well be the case, 

On more than one occasion I have came across a guy with a new CDI that says it works on the 2000-2002 models but does not. They all have created a no crank situation. In each case the purchased CDI said it covered multiple models instead of being model specific. 

Thought it might be applicable in this case as well. 

It seems like those years are the hardest to find the correct ones. I keep thinking with some time and ingenuity a different model CDI could be adapted, but luckily I have always been able to scrounge the correct one up somewhere, so far. 

[mga]

not sure where you live, but someone on FB Marketplace is parting out a Big Bear in Richmond Kentucky

[Gwbarm]

Thank you for the info, I will check it out.

[Gwbarm]

I know this thread is getting old too many projects going on at once plus honey doos, I v been working on the wiring on the big bear not making much progress, at this point im just trying to get the starter to go by pushing the button

At the solenoid the blue and black wire go to the start button from the start button  if it was not aa generic start button.

There is continuity from the blue/black wire from solenoid to the main harness connector pictured to the far left is the connector to the switch you can see the colors don't match up so iv been trying to figure what goes where and the connector in the center goes to the start stop switch. I hooked it all back up and went to the starter cutout relay and bypassed it and got the oil/temp light to light up, so I know its bad, with this bypassed I push the start button and the light goes out as long as I hold the button down.

So I opened up the switch the black/white and black wire goes to start/stop switch and red/white and blue got to start button.So I thought I would run this by you guys may you can catch something I missed, I think I have a grounding issue somewhere in the harness but haven't found it yet. 

[Mech]

I see there are two manuals here, up to 2000 and from 2000 onwards..  Are you using one of those two ? Which one and I'll download it and have a look at the diagram.. 

[Gwbarm]

Thanks I appreciate your help, I am using the 2000-01 Big Bear 400 repair manual.

[mga]

1 hour ago, Gwbarm said:

I know this thread is getting old too many projects going on at once plus honey doos, I v been working on the wiring on the big bear not making much progress, at this point im just trying to get the starter to go by pushing the button

At the solenoid the blue and black wire go to the start button from the start button  if it was not aa generic start button.

There is continuity from the blue/black wire from solenoid to the main harness connector pictured to the far left is the connector to the switch you can see the colors don't match up so iv been trying to figure what goes where and the connector in the center goes to the start stop switch. I hooked it all back up and went to the starter cutout relay and bypassed it and got the oil/temp light to light up, so I know its bad, with this bypassed I push the start button and the light goes out as long as I hold the button down.

So I opened up the switch the black/white and black wire goes to start/stop switch and red/white and blue got to start button.So I thought I would run this by you guys may you can catch something I missed, I think I have a grounding issue somewhere in the harness but haven't found it yet. 

damn, sure looks clean. I looked at my solenoid and it's wired the same colors. Unfortunately, i'm not going to open the starter swwitch because i know if i do, it'll lead to another issue. To me, if the lights go out when you push the start button, it seems like a short somewhere. I'm guessing of course, but you might be right about a bad ground.

1 hour ago, Mech said:

I see there are two manuals here, up to 2000 and from 2000 onwards..  Are you using one of those two ? Which one and I'll download it and have a look at the diagram.. 

are they different? I downloaded one myself.

[Gwbarm]

I haven't looked at the other manual, you are right inside the starter switch is very clean shouldn't be a problem there I wasn't expecting that because the wires on the plug in side are very faded, but it looks to be a fairly new switch.

[Gwbarm]

Mech just checked to make sure which manual I was looking at it is the 2000 Big Bear / Kodiak WFM400FWA[M]

[Mech]

Ok. I just found one for 2001-20014..  but I'll get the one you have, and have a look..  horrible complicated wiring these yamahas have.. I bet it has about nine wires into the cdi.. at least !! And too many complicated isolation relays.. 

I'm drinking beer now though, so don't expect any sense out of me(yeah right) before tomorrow morning..

[Gwbarm]

I was just looking there are several on there that covers the 2000 Model BIG Bear with different letters on the end, according to my VIN number search I have YFM400F/YFM400FH I may be looking at the wrong manual because I did see one for the YFM400F.

[mga]

9 hours ago, Gwbarm said:

Mech just checked to make sure which manual I was looking at it is the 2000 Big Bear / Kodiak WFM400FWA[M]

so, what exactly are you chasing there? maybe i can look at my wiring and compare or let you know what goes where?

[Gwbarm]

Trying to figure out why the start button won't make the starter rotate there is a discrepancy in the wiring harness somewhere.

[mga]

28 minutes ago, Gwbarm said:

Trying to figure out why the start button won't make the starter rotate there is a discrepancy in the wiring harness somewhere.

ok, some dunb questions first...with key on, you have power to the swwitch, correct? then power out to the starter solenoid...right? have you tried jumping the solenoid to see if there's any reaction? is it gounded properly? 

I'm no expert, just going by my basic understanding of electronics. 

[Gwbarm]

Thanks for the help! battery hooked up, turn key on, the neutral light lights up, the oil temp light does not, the starter does work there is power to the solenoid the starter will work when I jump solenoid with screwdriver.  If I take the starter circuit relay out of the harness and bypass it with jumper wires the oil temp light comes on and I push the start button and it goes off until I release the button.

[mga]

6 minutes ago, Gwbarm said:

Thanks for the help! Battery hooked up, turn key on, the neutral light lights up, the oil temp light does not, the starter does work there is power to the solenoid the starter will work when I jump solenoid with screwdriver.  If I take the starter circuit relay out of the harness and bypass it with jumper wires the oil temp light comes on and I push the start button and it goes off until I release the button.

  You said if you jumped the solenoid, it activates the starter...right? When i turned my key to ON, I checked the wires on the solenoid...they all said 12 volts (the red and two blue wires)  And yours?

and when my key is ON, my Oil Temp light doesn't come on either. Just the neutral light.

[mga]

 

its pouring out, so i have time to look around...found this. I don't know if you saw this or not

 

Edited February 16, 2023 by mga

[Gwbarm]

Thank you for the info. I wasn't sure if the oil temp light should come on when key was turned on. I have 11.8 volts on both blue wires and 12.4 on red

[mga]

i watched both of his videos...very informative..at least for me. But, it was interesting how he diagnosed everything. I thought it might help you.

[Mech]

The temp light is meant to come on when you have your thumb on the start button.

The plug to the left in the middle picture.... what do you think that goes to ? I think the pink wire is for a horn..  Is the horn and the 2/4wd selector in the same switch ?