Gwbarm

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.

I think you are exactly right Mech, without the spring it worked fluidly and closed easily. When i put the spring back on it seems to push everything to the spring side, that why i took it all apart Didnt really see any wear on the shaft or the bore. I changed the spring, i thought at first the spring may be weak, no difference. Since you mentioned it i havent checked to see if their is something missing that keeps the spring lined up with the shaft, because it did seem like it wanted to pull in that direction with the spring on it. Spring shaft or none of those kind of parts are listed as replaceable parts. I will look at my other carb to check if there is another piece thats missing although its the one with the half moon cable hook up may be different anyway.

Well, that didnt really work out. Shaft from aftermarket is a little different. I am keeping my eye open for another carb, this one works good except for going back to idle, but its Ok i just have to goose it and it will go right back to idle. So its on to my next venture and spend some real money. The tires are in bad shape i have slimed them and slimed them and green is seeping out they were cracked and dry rotted really bad, it has been good enough to test with but a couple still leak down after a month. So i will be getting a set of Kenda Bear Claw EX , i have used them before and they seem to be good tires. I usually take them in and have them mounted, but this time im going to do it myself, i usually dont, because i dont really have the right equipment to do it and no more often than i need it havent purchased anything descent. Im doing it myself this time because i want to refinish the rims while the tires are off. We will see how that works out, not really something i enjoy doing, changing tires seems to fight me on every level.

Wow! That stuffs really gone up, i think the last i bought was maybe 1.99 a can

Kerosene, well that doesnt burn very well, i thought ours are mostly ethyr, maybe wrong, i dont use it much.

I always use non ethynol fuel, even if i have to drive 20 miles to get it, i have seen too many carbs ruined by it.