Gwbarm

Sounds like a fun project probably wont take much to get it running again, they are resiliant but dont like to sit around not being used for any length of time.

It would be harder to steer in 4 wheel drive. When you push the button to change from 2w to 4w drive do you hear anything try to happen. You might try rocking it back and forth while pushing the button and see if that might get it out of 4w drive.

Welcome!

Thats because the old man knows more.

Sorry to hear about your health problems getting worse, i dont see how you have done as well as you have, but preserving health is more important than any old quad. I dont think the parts from your 350 will work perfectly with the 250, carb may make it run, but not perfectly. Your son may do better by continuing where you left off on the 350. I wish you well, hope that your treatments work. I have enjoyed working with you and wish you well.

Sounds good, hopefully one of the broken wires will be to the pickup coil, then, fixing that will get you sparking again. A build thread would be good, i did that with my Big Bear, it kind of keeps things interesting, and for me it kept me motivated, mine was in a lot worse shape than yours, i had to figure out all the wiring, it was all ripped out.

Looks good, Should be a fun project , it seems to be all there, hopefully its not the CDI, that could be expensive, what have you done and found so far.

Welcome, a great group of people always willing to help, and added knowledge is always appreciated. Look forward to working with you, i always have some kind of strange project going on.

None that I know of

I would also check the regulator/ rectifier for proper operation.

Glad to help, hope it turns out to be something simple.

They are very good engines, i have been very impressed with the 400, i havent worked on the 300 much but have never heard anything but good about them.

Welcome to the group, when i have trouble finding manuals elsewhere, i go to manualslib.com.

Glad you got it fixed I had the Same problem with replacement didn’t line up exactly like the old one but it was close enough wires came out in wrong place

Welcome to the forum. If you enjoy talking about and repairing quads this is the place to be, a great site with friendly helpful people.

When you get it off, you might want to put the shaft in the freezer overnight before going on with the new bearing. It helps.

When i was working on my 2000 it ended up being a YFM400F, doing o Vin# search. I had problems finding the correct manual, i used both of these on this site, mine had the wiring harness stripped out when i got it so i had to completely rewire it, and there is a little difference between the wiring on a 2000 and a 2001 compared to the other models covered in the manual, my CDI and wiring to it was different. Never did find one exactly for my machine, hopefully you dont have that trouble. Dont get me wrong, the manuals were a lot of help, couldnt have done it without them, but they were not exact for my machine, i just figured it out. Just thought i would add that bit of information, from my expierience.

I would wear welding gloves or figure out a way to hold it solid before you heat it, if not as soon as you hit it with the hammer and punch it will bounce out of position and first response is to grab it and position it back , but it is hot and it will burn you, just relaying my expierence.

I would also try some fuel injector cleaner in the fuel, I use Berryman Chem Tool you can get it at Wal mart, i really like this stuff, it actually works.

Yeah! When mine borrow stuff i just take it to them, dont really expect it back, so I get myself another one.

Great information! Thanks for that Mech.

You are right they should burn when it’s running you can check to see if you have voltage on the light wires and check the switch for proper operation

Just looking at your photo looking like lights are not there are the wires intact and no battery hooked up.

Sounds interesting! Everything you have replaced should have you sparking, the CDI should be by the voltage regulator, does it look different from the one you replaced, there arent 2 CDIs unless it was rewired and previous owner didnt remove the old one.

Sounds like carb issues, i would have thought, like you, starting and running it would have kept that from happening, if you are running ethynol fuel it has a tendacy to form a jelly like substance in the carb from sitting, if thats the problem, fairly easy to clean up, if it hasnt rusted everything in there.