[thorne]

Start with this. Let me know what you're finding, any questions, and if you want me to continue. There's a discrepancy between this chart and the wiring diagram (in the same manual), w/ regards to cdi inputs. I need to figure it out before I send more.

Below is an image of the starting circuit for the yfm600 98-01. Battery (2) is at top, (1) is main fuse, from which hot is sent to the main (key) switch (A). From what you've said, your fuse is okay, but you could verify.

Below the battery is (3) starter relay, (4) starter, and (6) start button. Diagnosis of the starter relay, and starter circuit cut-off relay (SCCR), is described above. Your starter is cranking, so we don't need to go into that. To verify function of the start button, follow the wiring to the opaque six pin connector with R/W (red/white) and B (black) wires at the corners on the lock side. You should have continuity between the two pins when start button is pressed, open line when not. The B (black) wire brings ground into the switch and the R/W sends it out to the starter relay. Verify at the connector that the black wire coming in has continuity w/ a good ground (frame or block). Verify also that you have continuity from the R/W (red/white) that leaves the start switch connector and the same color wire at the starter relay connector. Make sure you're on the correct side of the connector when you check these. If your start button works properly, you have a good ground into the switch, and continuity from the switch to the starter relay, then the starter relay is getting ground, but not hot.

The starter relay gets it's hot through the L/W (blue/white) wire from the starter circuit cut-off relay (5). When the SCCR is engaged, it sends a hot that comes from the main switch (Br) to the starter relay on a L/W (blue/white) wire. The Br (brown) wire from the main switch also provides the hot to activate the SCCR. The ground side of the relay comes from the cdi.

For now, verify you're getting hot to the SCCR from the main switch along the Br (brown) wire (remember there are two brown leads in, one to activate the SCCR and the other to provide the upstream side of the relay). Remove the SCCR from the connector, turn the key on, and check for 12v dc between the two Br (brown) wires at the back of the connector to the SCCR (from the main switch) and a good ground (frame or block).

The ground line needed to complete the circuit and engage the SCCR comes in on a Y/B (yellow/blue) wire from the cdi (7), based on inputs that show below the cdi on this chart. It's complicated, and as I had stated, there's a discrepancy between this chart and the wiring diagrams. Will send more as quickly as I can get through it. We have snow, high winds, and very cold temps forecast the next 3 or 4 days, so it may be a few days. I'll do the best I can.

 

[brando040]

i have continuity at the start switch when pressed. I also have continuity at the r/w wire on the starter relay. I also checked continuity on the ground wire at the switch to the battery and good there also. I hv power at the the brown wires also. I replaced the blue/white wire from the sccr to the solenoid itself just to eliminate having a bad wire. If I put direct power to the blue white wire from the battery it will fire with the switch whether the key is on or off. so something isnt sending power to the wire when the button is pressed. thank you for taking the time to help me out... merry christmas...

 

[brando040]

i took a jumper wire and ran it from the yellow with a black tracer wire which goes from the sccr to the cdi. i ran rn a jumper from that wire to ground and the sccr clicked. if i left the wire atttached to ground the bike fired right up. ??

 

[thorne]

It'll take me a bit to digest all that and follow it through the chart. On just a hunch, what happens if you pull the single pin at the neutral switch (right above where the shifter lever enters the engine), connect that wire direct to ground, and w/ everything else connected normally, key on, and you hit the start button? Make sure it's in neutral at the gearshift.
I'm dealing w/ a similar problem, so I don't have a "good" unit to test, mine being broken as well.

 

[thorne]

What you wrote above would indicate that one of the inputs to the cdi is not providing what it requires to send ground to the SCCR. I think it may be that neutral switch lead.

 

[thorne]

Just put the legend and the trouble-shooting chart for switches together on one page. Thought a copy might be helpful for you, so added a copy here.

 

[PapaGrizzly]

Brando040: Have you resolved your issue? As I'm having the same issue with my 2001 Grizzly YFM600. If so, kindly advise how you fixed your machine. Thanks PapaGrizzly

 

[thorne]

I hope so. I have the carb back in. It started, idled smooth, revved fine. Took it for a short drive in the snow. Didn't get it to top rpms though, due to conditions. It was putting out a little fuel initially from the overflow, but then stopped. It did that the first time I put the carb in, then it diminished over time. I have the same small diameter clear tube over the overflow port that I used to check fuel level from the drain port, bent up and secured to the frame, so that I can keep track of it. The first time, it would get as far as about a half inch into the tube while running, then it would suck back in after I'd stopped. Just going to leave that on rather than the typical overflow to the back end so that I can keep an eye on it for a while. That's why I took it apart to check the float level. So I guess I'm back where I started, really.
As far as what I did.. I moved the tang downward (toward the needle valve) a little (doesn't take much) and then wasn't dripping out the overflow when I provided fuel. I used the clear tube method to check fuel level and it showed about a half inch below the mating surface. I shut the carb drain, tipped the tube down to drain it and repeated the process. It was about 3/16" higher the second time. Did it again and it was higher still, about 3/32" below the mating surface. Did it a fourth time and it was same as the third. Can't explain it, but that's what happened. I had fuel supply to the carb throughout.
The clear tube on the drain port is nice, as I can see if it's putting anything out into the overflow. If the carb was really dumping, it should come up to a level equal to the top of the drain port in the float chamber, but it hasn't come out more than a half inch into the tube so far.
It helps a lot to be able to mount the carb firmly for the test. I put a 1x2 in a vise, then clamped the carb in between against another piece of 1x2. I have a small temporary fuel tank w/ clear line that I use to provide fuel to the carb. It may be important that the screws holding the bottom half on are tight, as there are posts inside that the float cage sits against.
Let me know if you have any questions.

 

[thorne]

My apologies, papa grizzly. I have been working on the carb, had just asked a question about it in a different new post, assumed you were responding to the posts I'd made today on that thread.
I did figure out my electrical problem, but I see that your question is directed to someone else in the thread. Once again, my most sincere apologies.

 

[PapaGrizzly]

Throme..........thanks for the reply, I purchased my 2001 Grizzly YFM600 on June of 2000 and the unit has basically been babied as I've used it for trail riding and hunting in SW Colorado. When not in use the unit was in a climate controlled environment with a battery tender attached. That haven been said the unit has 1,660 miles on the odometer. About six months ago I used the unit spraying weeds was running fine, parked in front of my home and when I went to start the unit, while in neutral and pushing the start button, nothing but the temperature light came on. Brought it back to my home in Aurora, CO, stripped down the back part of the unit checked all of the electrical connections, jumpers everywhere and miraculously when I hit the start button it fired up. Put the unit back together and it sat in the garage until the first minor snow, last Fall, as I have a Warn plow for the unit. Parked the unit in the third bay of my garage, when to plow snow and same issue. Turned the key on, pushed the start button while in neutral (neutral light was on) and again nothing other than the red temp light came on. I then pulled the left-hand brake and checked for continuity, checked okay. The unit has, that I could find from the shop manual, -4- relays, three in front of the storage box, two white (from left to right) and a red relay on the right. Checked the two white relays with audible clicks and continuity between the terminals. However, the red relay had continuity without power being applied and when I applied power there was no continuity. The fourth relay was hanging down below the air box, pulled it and when applying power, it clicked. I reassembled the relays to the connectors and used dielectric grease on each. Pulled the starter solenoid, it checked okay, checked all fuses in the battery area, all okay. Turned the key on and hit the start button and once again miraculously power to the starter. The connector to the solenoid has two wires, on red/white and one blue/white. If I attach a jumper to the red/white terminal and attached my test light grounding to the negative post of the battery, turn the key on and push the start button my test light illuminates. Tells me there is power to the soleniod. I then proceeded the same with the blue/white wire placing the test light on both the positive and negative posts of the battery and nothing. If it were the ground side my test light should have illuminated when I touched the positive terminal. I failed mention that I jumped the solenoid putting a jumper cable from the positive post of the battery to the starter cable side of the soleniod and the starter engages. SOOOOOOOOOOO, any idea on what is causing the blue/white wire of not getting grounded when the key is on and the starter button pushed? Any assistance would be appreciated! Thanks!!

 

[thorne]

Because of the intermittent nature of what you're experiencing, amplified by the cold weather (I'm in Greeley myself.. -2 this morning), it sounds to me as if you have a connector not always making good contact, or your cdi is going.

The blue/white (L/W on the wiring diagrams) sends hot to the starter relay/solenoid from the starter circuit cutoff relay (SCCR), and the ground (red/white R/W) comes from the start switch. The SCCR gets two hots (both brown Br) from the main/key switch, one to power the relay and one to provide the hot across the relay to the blue/white (L/W) that goes on to the starter relay/solenoid. The SCCR gets the ground that engages the relay from the CDI (yellow/black Y/B).

It should be the case that if you disconnect the larger connector of the two at the CDI, jumper a ground to the yellow/black (Y/B) pin on the connector, turn key on and hit the start switch, that the starter should turn. That will tell you the problem is at the CDI or upstream of it, meaning one or more of the several grounds coming into it on the start circuit isn't getting there.

I've attached an image of the complete wiring diagram that I drew up that will make it easier to track than the greyed out diagrams in the manual. (It isn't clear right below but if you click on the thumbnail at bottom left, it's readable). At top right I have images of the CDI connectors with wire coding. The yellow/blue Y/B wire is bottom row, second from left, when the connector lock is at the top. The starter is right in the middle where the two pages are taped together.

Get to that point and let me know the results and we'll go from there if you want further assistance.

 

[thorne]

My error. I thought the thumbnail that you could click on for the full image would show up in the thread but it did not. Will try again or send it to you separately.

 

[thorne]

 

[thorne]

That works; click on the thumbnail and it's a decent image.

 

[thorne]

Just wanted to close this out, as potential assistance to someone having a similar problem. Due to the complexity and difficulty of solving this typing back and forth, I contacted PapaGrizzly directly w/ my phone number. We worked together to diagnose it, and were able to solve the issue.

Ruled out the starter circuit cut-off relay and starter relay/solenoid as described above..
"It should be the case that if you disconnect the larger connector of the two at the CDI, jumper a ground to the yellow/black (Y/B) pin on the connector, turn key on and hit the start switch, that the starter should turn. That will tell you the problem is at the CDI or upstream of it, meaning one or more of the several grounds coming into it on the start circuit isn't getting there."

The starter did turn. Began checking inputs to the cdi, starting with the ground input from the main switch (MS) and engine stop switch (ESS) by way of the black/white (B/W) wire. That wire originates in common from the MS and ESS and goes directly to the CDI, w/ no other participation, terminating at the top right pin of the 8 pin connector at CDI (w/ connector lock at top). It sends ground to the CDI when either or both of the MS and ESS are set to off, and does not send ground only if key is on and ESS is set to "run."

Checked for continuity with ground at the CDI pin, and found we did have ground in all positions of MS and ESS, which should not be the case. Opened the white four pin connector to the key switch and the single pin connector (B/W) from the ESS, which would eliminate the ground if it were coming from a defective MS or ESS, but still had continuity with ground at the B/W top right CDI pin.

Cut the B/W wire downstream of the MS connector, and where it goes into the CDI 8 pin connector (top right w/ lock at top) and ran a jumper wire between them, reconnected both connectors. This restored normal function and the unit started right up. So the B/W wire w/in the wiring harness is shorted to ground somewhere between the two points in the wiring harness. PapaGrizzly ran a separate wire from the MS to the B/W wire at the CDI connector, and is up and running.