n0uy
XS400 Member
Hello everyone. I am new to this site and I have recently purchased 1981 400 special that has been sitting in an old shed for at least the past 5 years. I am have some difficulties getting everything going but making progress. I am 60 years old now but used to ride quite a bit in my 20's mostly on a CB 750 Honda because that's what was available then.
I am into ham radio and bought this bike from another ham that needed some money for other things. To start with, the crankcase was full of gas and oil. Drained that and put in new oil and filter. Pulled the carbs and took out all the jets and cleaned the jets and passages. Only one I didn't remove was the starting jet located in the throat. Checked the needles and seat and they are worn but holding for the most part. The slide diaphrams were in good condition so put them back in after the jet cleaning process. The air elements were saturated with gas and falling apart so put in new ones. Made certain all the rubber connections to the cylinders and air boxes were good. First time out it ran pretty well for a while but acted like it wanted to flood so i believe the needles are showing their age. I since have replaced the tank valve with a different one so the filling the crankcase shouldn't happen again.
Now it is very hard to start. wants to hit on one cylinder until the rpm is up to 2500 or so. then they both clear out and it idles good and responds ok. If you ride it for a bit it starts to act like its flooding again and misses on one cylinder. I checked compression and they are similar. 78 on one and 85 on the other. My next step is to check out the points and condensor or cdi. I am not sure which it has yet. i didn't get a manual with it so I am going by the seat of my pants so far. I have been in manufacturing most of my life and I was the factory service man for 20 plus years so i have some experience in this area. I have never owned a Yamaha before but I am lovin the heck out of this experience so far. Makes me feel like a kid again which is great. But I assure you, I am not. Any advice from the members on this rascal sure will be appreciated. BTW, the bike only has 1,750 miles on it so it should run me to work and back and on local rides for many years hopefully.
Ray
I am into ham radio and bought this bike from another ham that needed some money for other things. To start with, the crankcase was full of gas and oil. Drained that and put in new oil and filter. Pulled the carbs and took out all the jets and cleaned the jets and passages. Only one I didn't remove was the starting jet located in the throat. Checked the needles and seat and they are worn but holding for the most part. The slide diaphrams were in good condition so put them back in after the jet cleaning process. The air elements were saturated with gas and falling apart so put in new ones. Made certain all the rubber connections to the cylinders and air boxes were good. First time out it ran pretty well for a while but acted like it wanted to flood so i believe the needles are showing their age. I since have replaced the tank valve with a different one so the filling the crankcase shouldn't happen again.
Now it is very hard to start. wants to hit on one cylinder until the rpm is up to 2500 or so. then they both clear out and it idles good and responds ok. If you ride it for a bit it starts to act like its flooding again and misses on one cylinder. I checked compression and they are similar. 78 on one and 85 on the other. My next step is to check out the points and condensor or cdi. I am not sure which it has yet. i didn't get a manual with it so I am going by the seat of my pants so far. I have been in manufacturing most of my life and I was the factory service man for 20 plus years so i have some experience in this area. I have never owned a Yamaha before but I am lovin the heck out of this experience so far. Makes me feel like a kid again which is great. But I assure you, I am not. Any advice from the members on this rascal sure will be appreciated. BTW, the bike only has 1,750 miles on it so it should run me to work and back and on local rides for many years hopefully.
Ray
