Hey everyone in yamaha land,

This is my first post and first of many questions concerning my "new to me" 1980 xs650. I am new to the xs world, I have always had yamaha dirt bikes but not street bikes. I bought the bike about 2 weeks ago off of craigslist for $375, not running and not knowing what was all wrong with the bike. After a saw it in person I had to have it, I will try to include pics. I got it home, admired it for about a day, then I decided to start the process of getting her going. First I hooked myboat battery up, took the plugs out and put a shot of gas in the cylinders, checked the oil and kicked it 3 times and it fired off for about 2 seconds. The guy I bought it from stated that he did not ever hear it run since he bought it 10 years ago. The next day I removed the carbs and soaked them overnight in carb cleaner, everthing looked pretty good inside the carbs for being 30 years old. I reassembled the carbs, hooked up a spare hamster water bottle for a fuel I.V. since the gas tank has about a 1/2 inch of rust and varnish on the inside. I kicked it one time and it started right up but ran irratically, I checked all of the air/fuel adjustments and I came to the conclusion that the diaphrams were leeking air. I then remembered I forgot to tighten up the clamps on the intake boots. runs perfect now. I was thinking this is to good to be true, until last night I decided to run through the gears. I popped it in first and the back wheel spins but the chain jumps around alot, and when I put the back brake on the wheel stops and motor keeps running while in gear. All the other gears and clutch work fine. So now I geuss I will dive into trans repair, which I know nothing about. I was wondering if the motor could be removed and side covers removed and flipped upside down to split the cases without removing the top end. I will appretiate any help or advice from all of you gurus, and if anybody else has had this problem.

Thanks in advance

Craig from Texas U.S.A.

Broken drive dogs are not uncommon on the XS, my '76 suffered this fault too. Yes you can turn the engine upside down and remove the lower crank case half without taking the barrels off.

Make sure you get the correct parts. Yamaha changed the clearance on the gears/shaft, the wrong parts will fit but make the box impossible to select gears correctly.

Broken drive dogs are not uncommon on the XS, my '76 suffered this fault too. Yes you can turn the engine upside down and remove the lower crank case half without taking the barrels off.

Make sure you get the correct parts. Yamaha changed the clearance on the gears/shaft, the wrong parts will fit but make the box impossible to select gears correctly.

Thanks for the reply, I am going to take a look closer tomorrow.

Thanks again