Greenerict

They both warmed up, and there is a spark on both sides. The O-ring and washer came out after the mixture screws. Everything looks fine. I just need to find some plugs now. And I'll check for leaks if this doesn't work out, I appreciate the help

I drilled the plugs out, and only the screw and a spring came out on both sides. No o ring or washer did. And they seemed to be screwed in pretty tight... Oh and mikesxs is out of plugs...Sigh..

Will Part #48-5012 on Mikesxs work? And do I need a new float needle? Will Part #48-5014 for that?

I took the carbs apart, and am soaking the parts now. One of the "buttons" on the float bowl needles are stuck, so I should order one of those? Also there was crud on the seat(not sure if that's what it is, but it's what the needle rests in). I have no idea where the pilot mix screw is, the diagram in the book I have is different from my carbs, I'm pretty sure. Also in the book it says the float bowl height should be 32mm.. Is this plug where the pilot mix screw is? And attached is a picture of what type the carb is...just to be sure it's the right one...

The carbs looked fine before I changed the filter (there was one before). I'll soak the stuff in cleaner tomorrow, and do what you said about the pilot screws, if I can find them. Thanks.

That position is "prime," and it ran in that position

I blew out the jets in the carbs. the diaphragm seemed kind of stiff (just a little) and the gaskets were pretty stiff too. I am using an inline filter. Actually, while I was writing this I went out to take a pic of the filter. And it ran on full choke at 1200, when I put it to half choke it dropped to 1000, and once I put it on no choke it dropped to 500-750 then stalled. It was burning oil, but not anymore (that's my fault). Attached is a picture of the filter. It was clean when I put it in (like peach colored). Uploaded with ImageShack.us

New problem. It's not running.I cleaned the carbs and changed the oil today. It started and ran for 2 seconds at the right rpm a little while ago, but except for that it won't start. Before it started, it wouldn't run; so I opened the gas cap then tried to start it and it worked, but maybe that was just luck, because after that it didn't start.

Well it was sitting there not moving, and the tachometer was between the 0 and the 1. I'll try it again later today and see what happens. If it happens again, I'll try and take a picture.

Hi, I have a 1980 Yamaha XS400 Special that only fires on one cylinder. Recently, I cleaned the carbs, changed the fuel filter (the old filter was black and really dirty, and debris was floating around after I disconnected it.), and put new fuel in it then it ran fine. I then put some oil in it and it ran even better. Yesterday, I put more oil in it (since I didn't put a lot in it originally) and tried to start it up and it did so reluctantly. It idled at around 750 rpm, and stalled out a few times. It also stalled when I shifted into first gear. What do you guys think is a possible problem? I'm looking around these forums as much as I can for a solution. Thanks, Eric

Yea...That is the guy (and his car) who I bought the bike from

Hey, so I just bought my first motorcycle, a 1980 Yamaha XS400 Special for $400. The guy I bought if from said that it ran on one cylinder only. He cleaned the carbs then it ran fine for a day, then went back to only one cylinder. I haven't been able to start it up, since the battery is dead, it's charging now. I don't know...anything, really, about motorcycles, so wish me luck. Thanks -Eric Uploaded with ImageShack.us Yes, I know the seat's missing, I took it off so it wouldn't fly off while I was taking the bike home..