Yamaha Timberwolf 250 need help

[Atvguy0901]

Thank for the add on quad crazy. I am new here and need some help with my atv. It’s a older Yamaha Timberwolf 250 that I purchased second hand from an person. I got it home ans started to look into it. He stated it needed a cdi box so I ordered one for it and a battery as well also a key switch cause it did not come with one. I put all the parts on it and when I hit the start button it just clicks and noting else. Thank you any help is appreciated. 

[Gwbarm]

My first thought would be bad starter solenoid, you might check the connections make sure they are tight .

[Mech]

It could be a bad connection, uncharged battery or  bad starter.. 

Do the lights dim right out when you push the button ?

Did you charge the new battery ?

Have you tried bridging the two big contacts on the starter solenoid or used a jumper to put battery positive straight to the starter. If you put power straight to the starter and it doesn't go, then the starter is crook or you have a bad earth connection or lead. That would be the first step I think..  Try that and report back what happens.

[Atvguy0901]

To the top post the connection are tight. Also want to mention I had to Wire on the key switch and there is one wire that I am not sure about on the wires.  And to the bottom post yes the neutral wire is going dim when I press the button on the switch. And the battery is brand new also fully charged And yes I have and noting no spark or anything. I will include a picture of the wire i am tlaking about on here and see if anyone can help me. To note its a aftermarket key switch and everything. 

[p5200]

I think I would try bridging the batt and starter terminals and see if it cranks. I bought a cheap solenoid for my atv which lasted less than a week. It clicked but, used aligator clips with voltmeter across batt/starter terminals. when I hit the start button sure enough, it read full battery voltage indicating open circuit between batt/starter terminals. So, I put the old solenoid back on and it started right up. I'll try to buy as much OEM parts as I can afford, after that. 🙂

[Gwbarm]

 I would look at starting circuit wiring diagram in the manual, make sure the key switch is wired to the correct wires, sometimes aftermarket switches don't have the same color code as OEM harness,I think jumping the solenoid to see if the starter works as Mech, and p5200 suggested, would be first step, it would tell you if your starter is good, bad starter would be pulling lots of AMPs and cause your light to dim. Key switch wired wrong would also cause this. 

[Atvguy0901]

Ok thank you everyone for the suggestions I will try that and report  back to you guys. I also want to mention that it clicks with the start switch in the off position as well but i wil try bridge the two post on the starter solenoid and see what happens. And also to note the starter solenoid relay I can hear it clicking when I press the start button but I will try what was suggested first and let you all know. Thanks 

[Mech]

If you shorted across the two big terminals on the starter solenoid and there wasn't even a decent spark, and the starter didn't spin, then you have a bad connection somewhere in the main big wires or their connections or a crook starter. If it's the starter it is most likely because the brushes inside are worn out or stuck in their holder from sitting too long.

If you know how to do it, you could use a volt gauge as P5200 is suggesting and carry out voltage drop tests all along the starter cables, earth cable and between the starter and engine.. Or, the easier thing, which is to pull the starter motor out and test it on the bench with a battery and jumpers. Most starters come out real easily..  That's probably the easiest, and likely to be where your problem lies too. Starter brushes give a lot of trouble.

Edited March 20, 2023 by Mech

[Atvguy0901]

Ok thank you for the suggestion I will try that and report back 

[Gwbarm]

You say it clicks with the start/stop switch in the stop position, you might want to check that , sounds like you might have a ground problem.

[Atvguy0901]

I took the start/stop switch apart and everything looked good in there and I will point out in that picture i posted there a black wire running  from the key and start stop switch with the other black wire coming off of that. I hook it to the red wire on the key switch wiring the other day and hook up the battery and it blew the 10am fuse. So I am waiting to get another fuse and try different ways to wire that black one with the black one coming off of it. To a different wire and see what happens. I am not sure if I said this but it did not have  jet switch when I bought it. The guy told me with a hot battery and a new cdi box it would run but you know how you can’t trust people nowadays. Also  i had to cut the old plug and wire in the new key switch and I hooked them up color to color but like I said I am not sure were that one wire goes that’s coming off the existing black wire near the key switch. 

[Gwbarm]

Sounds like you hooked positive to negative and that what blew the fuse, what year is it and I will see if I can find a wiring diagram and take a look, sometimes aftermarket key switches are not wired with the same color wires as OEM.

[Mech]

Yeah Atvguy, you need a wiring diagram..  And as Gw says, there are different switches for different models.

To identify the wiring correctly, and the switch, we really need to know the exact model.. We need the whole model designation, with it's suffix..  YFB250***.. What's the *** ?

If we can't find the *** they you need to look at the several wiring diagrams there are and figure out which one you have. One major difference is in how the main switch is connected up internally, and another will probably be how the starter wire branches into the cdi or comes out of it. If you can identify those two things then it narrows the possibly models it may be down.

Edited March 21, 2023 by Mech

[Mech]

See if this seems to be like your wiring..   If the plug colours, or wire colours, or the main switch doesn't seem the same, then it's not the right one.. 

output.pdf

[Gwbarm]

I just pulled up one YFB250FW 1994-2000 it shows a stop button with a start switch, sorry for the poor quality internet grab

[Mech]

Dang Gw..  Your cdi has more wires than mine..

[Atvguy0901]

Sorry everyone for just now getting back to you so late I have read everyone responses thank y’all very much for help me with this and I am not a big fan of electrical stuff but I have found the vin and it’s a 1994 Yamaha timber wolf 250 2x4. Also just wanted to point out that the wires for the old key switch and new one match up but I am unsure of what the black wire running from the start stop switch has another black wire coming off of it and was hooked to something. That’s my biggest thing trying to figure out at the moment. Again thank y’all very much for your help. And I am hoping now I know what year it it’s it can help me to look up wiring and get this figured out and riding. Also going to include a picture of the old key switch plug and the new one. 

[Gwbarm]

I don't know if this is the correct wiring diagram for yours , it shows a stop button and a start switch, your B/W wire from the  start switch goes to the CDI and the black goes to ground.

[Mech]

Yup, the plain black wire is an earth that runs all through the bike, and the handlebar kill switch has a single wire connector going to it. The other kill switch wire is black with a white stripe.

If you count the number of wires going into the cdi you should find either Gw's diagram or mine will fit. The two diagrams have different numbers of cdi wires.. 

[Mech]

If your bike has an eight wire cdi..  I think I have a diagram for that too.. 

Edited March 22, 2023 by Mech

[Atvguy0901]

The cdi box is a 8 wire cdi box on my atv 

[Mech]

This might be it..

YFB250F-94.pdf

[Atvguy0901]

Ok thank you very much for the info I also just wanted to say I took the starter off tonight and bench tested it and nothing happened. So I took it apart and this was on the inside 

[Mech]

If it\s a sort of crumbly metal it's a brush. You get new brushes with new springs and the plate they are mounted on all together for a few bucks.

You need to check the armature and commutator for damage, and give the bearings a spin and see they are quiet, lube them if it seems like they could do with it. The bearings mostly last for several sets of brushes. .

When you're putting it together it's a good idea to smear a bit of vaseline on all the joins between parts and the O rings. It keeps the water out.

[JSL]

If you don't feel comfortable rebuilding your starter. I've had good success with aftermarket starters. and most are affordable. I generally rebuild mine, but it is easier just to order one. I do mechanic work for a living so feel free to contact me anytime. Good luck

 Oh, and I know you are not there yet, but if you have carb trouble after you get her cranking DO NOT buy an aftermarket carb. most are junk. Rebuild it. they are fairly simple and easy to rebuild. 

[Atvguy0901]

Ok I will look into it and see thank you. 

[Atvguy0901]

Ok thank you for your input. I actually purchased a new starter. I am a mechanic myself so pretty handy with this kind of stuff only thing I never attempted to rebuild a stater. I am always afraid I am not going to put it back together right and end up buying a new one and also have took the carb apart and cleaned it. And I appreciate everyone help and if I have more questions I will definitely ask here 

[p5200]

7 hours ago, Atvguy0901 said:

Ok thank you for your input. I actually purchased a new starter. I am a mechanic myself so pretty handy with this kind of stuff only thing I never attempted to rebuild a stater. I am always afraid I am not going to put it back together right and end up buying a new one and also have took the carb apart and cleaned it. And I appreciate everyone help and if I have more questions I will definitely ask here 

If, you take plenty of photos when you take something apart, it's a lot easier to put it back together correctly at least is is for me good luck. 👍

[Mech]

I've always taught people to lay things out to a method when they are pulling things apart.  So everything gets taken out and then layed down in the same order they came out. The first part on a shaft goes to the left, left side down, then the next part to the right of that and left side down then the next goes to the right and left side down. Or, outer part nearest me and flipped so the outer is down, then the next further from me and outer side down...  And I always use the same technique,, Near me, or my toolbox which is at one end of my bench. If I'm out on a job, the toolbox is still my reference point.

If we take a part out and inspect it for wear and damage, and make sure we understand what it is and does before we put it down, it aids enormously in making sure we repair every fault or potential future fault, get the quote absolutely right with no overlooked parts we have to explain later, and it always goes back together again correctly.

Ripping things apart in a hurry... is never a good idea.

[Gwbarm]

Good choice on the starter I have rebuilt many over the years, but the aftermarket ones have gotten so cheap I usually just get one of those, and they are good I have never had a problem with one.