Replacing my motor on 81 xs400 special

[Kayl]

I got my bike a year ago and I've slowly been riding it more and fixing it up little by little. I started riding almost everyday about a month ago and my nightmares started. My charging system goes out about 1-2 times a week. I took it to the shop and they couldn't find anything wrong with my stator or anything. I have always had problems with shifting above 1st but I usually get it within 10 tries. I was riding down a road near my house and I was trying to shift up after a stop light and it wouldn't stop going between 1st and neutral. I wasn't that far from my destination so I tried to push it hard in 1st and it blew and I had to pull over. Took it back to a garage and they basically told me that my motor was wrecked and it was going to cost upwards of 2,500. Now I found a motor on eBay for 300 that I want to install myself with the help of a couple of friends. Don't know if it'll work or if it's worthwhile but I want to try bc i love this bike and I'm ballin on a budget. If anyone has any advice I'll gladly take it. Will post updates as I figure more out.

 

[Kayl]

 

[NewHavenMike]

Get a workshop manual. Id start with troubleshooting the electrical stuff using a circuit tester and a volt meter to make sure everything is working. These bikes a simple and theres only so many things that can go wrong.. After that Id probably inspect the clutch parts and make sure nothing is too worn out, which may be causing gear shift problems...

If its all looking good, id take the engine out and split the case and give everything a good examination.. Its been a while since Ive had my engine completely apart but you may be able to get a look inside without having to split the case.

Lastly, stay away from that garage.

 

[arfstrom]

I had broken my kick start journal. so I had started to look on ebay, and anywhere else for same engine series as mine. I was forturnate enough, as all I need to replace was the bottom of the case, (in my case) I was looking for 4R4, I was able to get a 4R4. Of course beggars cant be choosier s. obviously a 400 motor will be fine, but if you can keep the one you purchase as the same generation of your bike, meaning points or no points system, (80-82) or earlier. Keep an eye open at your local bone yard.

once you get the engine out, still check out all the wires, make sure every wire is good, (no crunchie, rice crispy noises) as you move them. (stiff, none flexible wires) and replace as needed. my experience is just behind the motor, (bottom rear) the stators wires run up to the seat, those may make the rice crispy noises)

Good luck