1981 Yamaha XS400-"FLIGHT"

pr design

Been Around the Block
Alright lets try this again. I had a big write up about what I did so far today and hit post and it disappeared into cyber space. Maybe the Mars rover knows where it went.

This is my first bike. I spent about a month looking for something that would be in my price range, that was running and had a clean title. I picked it up for a dollar a cc. with the addition of some gaskets, a Clymer manual, the original owners manual, a new chain. It has a 4 month old front tire and battery.

First things first. I know that there is a new clutch cable that was installed. But the clutch doesn't engage until the lever is nearly fully released. I think that this should be a fairly simple fix, I just need to look it up or get some suggestions to how to get the clutch to start engaging slowing instead of suddenly right at the end of the release.

Second in order to get the bike to start and continue to run the choke has to be pulled all the way out. This leads me to believe that there is an air to gas ratio issue with the carbs. So I know that they need to come off and get cleaned out.

Today I decided that I wanted to see how it would ride so started it up and ran it up 2 streets from my house. It coughed along a little and pretty much dogged its way there. When I got ready to turn around it stalled and I couldn't get it to kick back over. So I pushed it back to the top of the hill and got it rolling and popped the clutch. It ran but stalled again before getting back to my driveway so I pushed it the rest of the way.

I pulled off the air boxes. To check the filters out. The right hand air box is cracked on the bottom. I don't know if fixing it with jb weld will be enough to seal it back up, or if I should just use that as an excuse to get pods. Also, I don't know if the filters are supposed to oily, but these definitely are oiled. Is this just to help trap particulates?

Took off my tank and then the carbs. The carb joints to the engine have some external cracking and they where missing the gaskets. Instead there was a orange silicon or caulk of some type sealing them to the engine. The left joints vacuum port was taped closed with electrical tape. These two things made me wonder if the choke is needing to be pulled all the way out to compensate for a lost of vacuum seal. I will be replacing them and just need to take the carbs apart and clean them to make sure that I won't need to add anything else to that order.

Only other thing I did today was I removed the crash bar from the front. Looks like she was blue at one point. She might get there again. paint schemes are the least of my worries at the moment.



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Re: 1981 Yamaha XS400-"no name yet"

Not sure if the 400 is the same set up as the 500 but if you look on the left side cover theres a lil cap you can pop out and the clutch adjuster is behind it .
If you have to replace parts and want NOS parts look up SPEED&SPORT or NWVintage both are good places to deal with and seem to have alot of stuff for Yamahas .
Nice looking bike to start ans sounds like your going about it right . Get it up and running and then mess with the looks !
Re: 1981 Yamaha XS400-"no name yet"

Yesterday I cleaned my carbs. Both bowls had rust in them. Where would rust come from? From the gas tank that looks really clean inside from the fill hole. I decided that I might as well drain it and clean the tank. I haven't purchase a cleaner yet. I figure something like CLR should do the job. Any better suggestions?

I ordered my replacement carb joints. And a set of Clubman bars with new grips and bar end mirrors from Alphamoto

Since I have to wait on that stuff to get here I decided to get to the next thing on my list.
Tank is emptied, so I figure I might as well paint my tank and side covers. The black looks great in the photos. What they don't show is that they are all orange peeled.

Bought some of the "environmental" stripper. I figure if It comes in a plastic bottle, I would be able to use it on the plastic side covers and not damage them.
The is blue under the black and even though I asked if the tank had any bondo in it and was told that it didn't, I have already run into some.
My plan is to fix the bondo areas that are there so that that are a little smoother. Then do a basic rattle can paint job. Something that will look clean and I won't feel too bad about stripping again when the time to do more renovations to the bike occurs.
Photo's once I get that accomplished.

Re: 1981 Yamaha XS400-"no name yet"

Carb rebuild












So all the parts came out and got cleaned. And then reassembled. Then the other side was the same thing all over again.
Re: 1981 Yamaha XS400-"no name yet"

So today yesterday I started stripping the tank and side covers.




So the black paint is bubbled up and scraped off to reveal layer 2 the blue paint.

At this point I have done 4 rounds of stripper. Down to bondo, bare metal and original paint and bare plastic.

The additional dent that I am filling.



I sprayed 2 layers of red primer. waited a couple hours and then hit it with a layer of black. The idea is to sand back to the red primer and then have accurate spots to fill with spot filler because the black is left in the low areas.


This is where the tank is at. The side covers did the same thing. I took lacquer thinner and wiped the primer right off the side covers. I guess I need to get an etching primer.

Do I need to take the tank down to bare metal or can I paint over the original paint. The stripper didn't touch it.
Re: 1981 Yamaha XS400-"no name yet"

So today was productive for me and the bike. First off I got the tank and side covers primed and wet sanded. The feel real nice right now. Just need to be patient and wait to start laying color down until at least tomorrow maybe Friday.



I also got a couple deliveries.

My clubmans arrived with new grips and bar end mirrors. They got put on right away and now I have a couple questions because of them.

The bars are shorter so the cables are cramped up around the triple tree. the clutch cable more so then the throttle.

Do the bar end mirrors go on facing up or down?

Also the carb joints arrived. I installed them but the question that I have about them.... When I purchased the bike only one of the vacuum inlets were hooked up the the petcock. The other one was taped over. should I have a "Y" joint joining both vacuums to one and then to the petcock?


A much better position for this bike in my opinion.
Re: 1981 Yamaha XS400-"no name yet"

its looking really good so far! I really like it!

as for the mirrors.. its preference really.. I had a friend with the same mirrors that ran them up.. but not because he liked them better up.. but because when they were down they hit his tank.. he liked the look and functionality better with them down.

your cables can be shortened yourself.. or you can pay to have a set made that are shorter (is what I did).
Re: 1981 Yamaha XS400-"no name yet"

Thanks JD.
Not sure where it is really going. For now I just want to get the painting done and get it so I can ride it. Once this winter rolls around, I will start looking at doing some more work to it. Still have a few things that I need to do mechanically too, but those are more basic tune up stuff. change the oil, and plugs etc.
Re: 1981 Yamaha XS400-"no name yet"

So today I started laying down color on the tank and side covers. Dark metallic bronze.


This is where I'm at.

This is at 6 coats of cover. About 1 and 3/4 cans. Tomorrow I will wet sand it and lay on another couple cover coats and a couple clear. After that I will be doing a little masking and then laying down some metallic blue.
Re: 1981 Yamaha XS400-"no name yet"

I think today would have been better if I wouldn't have even touched the bike.

Started off great. Wet sanded the tank and sides and washed them down with soapy water. Rinsed and then wiped them down with denatured alcohol.

Layed down 2 layers of color. Still everything is good.
First coat of clear and the difference between a covering layer on the clear and the color are two different things. The clear coat flows way faster. I got a run on the tank and decided that I would try a wood working trick. If you get a run while finishing in wood you can sometimes lift it off with some tape.
DO NOT TRY IT !! Or at least I shouldn't have.
Here is why you don't do it.

In addition, on one of the side covers the paint got little blisters all over the top of it. already wet sanded it down and will probably do a little more tomorrow after it has cured a little better.

Next the clutch cable needed adjusting. First off it wasn't engaging until just before it would let go. On top of that the new bars meant that I had a bunch of extra length. thought that I could maybe give it another curve and solve the issue with the length. That seemed to work. Followed the Clymer guide for adjusting the cable and went to squeeze the clutch and it wouldn't move. I was sitting on the ground when I pulled on it. So I got up and tried from above.

Next thing I know the whole lever is in my hand.

yes it looks like it was super glued before.
The real kicker....

See the little part behind the cable adjustment? That is a safety switch. I am having a hard time finding a clutch lever and bracket with a safety switch. Any one know were to get one? Or know of another model that use that setup?
Everything was going smooth. Guess that just is how it goes on 31 year old bikes.
Re: 1981 Yamaha XS400-"no name yet"

So I called the local yamaha dealer and they actually have the parts. Come to find out all that is necessary is that the bike is in neutral to start. The safety switch isn't needed. So I don't actually need the part with the switch mount. I got it anyway. Also got a new oil filter.
Sanded and repainted the tank from the tape incident. Starting to wish that cans had directional nozzles. That would make getting even coats easier then the round pattern that cans spray.
Re: 1981 Yamaha XS400-"no name yet"

So last night it stormed here. I didn't hear it. I had moved the board with the side covers after clear coating them yesterday and didn't bring them far enough into the carport. Or the wind was blowing the rain sideways. Either way the side covers had beads of water all over them this morning. When I wiped them off they look like they have golf ball dimples all over them. I think it is a pattern you wouldn't be able to repeat if you tried. So, I will either have to sand them back down or just live with it. I'm thinking I will live with it. I will probably remove them completely at some point in the future, whether I go and build it as a cafe or a brat, so I will let them be and who will notice. ME.

It is still kind of rainy today so I decide I would get the tank masked off and ready to lay the metallic blue down on it. The masking might not be prefect, but I think I'm pretty close side to side.

First laid out the center section. Tapered front to back and divided in typical yamaha style

Then I laid down a thin pinstripe and the curved fat stripe.

Covered the sides with newspaper.

Ready to paint. Here is the blue that I'm using. Should really pop on the tank.

I really want to set up a fan in the basement to blow overspray out the door, but I am just going to be patient and hope that it is nice tomorrow so I can lay the blue down.
Re: 1981 Yamaha XS400-"no name yet"

Im going to like thi s 8)
Re: 1981 Yamaha XS400-"no name yet"

dust coat of blue

first cover coat

6 coats

So I guess that the plan is to let this sit a couple days. Then wet sand it with the masking on. then hit it with a cover and a couple clear coats.
Then Strip the masking and another few coats of clear and it will be good to go.

Re: 1981 Yamaha XS400-"no name yet"

After wet sanding the first coats.

Cover coats before clear

2 coats of clear

I just need to pull of the masking and do an overall wet sanding with 1000 and hopefully not shoot anymore runs onto the tank. Probably 3 or 4 coats of clear and it will be looking tits.

Re: 1981 Yamaha XS400-"no name yet"

pr design said:
I just need to pull of the masking and do an overall wet sanding with 1000 and hopefully not shoot anymore runs onto the tank. Probably 3 or 4 coats of clear and it will be looking tits.


I like your paint scheme. Looking forward to seeing it when done. Keep it up.
Re: Re: 1981 Yamaha XS400-"no name yet"

I like your paint scheme. Looking forward to seeing it when done. Keep it up.
Re: 1981 Yamaha XS400-"no name yet"

Im curious how youre going to tackle the seat with the end of the frame curving up so much. Any ideas yet? I have a similar upwards curve on my XT500.
Re: 1981 Yamaha XS400-"no name yet"

kingkelly said:
Im curious how youre going to tackle the seat with the end of the frame curving up so much. Any ideas yet? I have a similar upwards curve on my XT500.
Well, I will admit it, I haven't really considered it. Right now I'm just trying to get some non wrinkled paint on the bike so I can ride it around until this winter. After that I will start considering what to do. My guess. I will cut off the back and weld in a loop. There are plenty of folks that have done good things with stuff like CM400's and those really have weird shit going down on the back of them.

Unmasking the side.

I took a razor blade and gently ran the corner of it along all the tape edges.

I wasn't expecting this.

Tape residue from the 1/2" tape. It was drafting tape.

After lifting the glue off with blue masking tape.

Still a little goo on it. Will goo gone cause any issues with the enamel paints?

I had to see what it would look like on the bike.


Well still work to do on this. BUT, it is looking pretty good. I need to figure out something that I can finish getting the glue residue off the tank. I thought that the denatured alcohol would do it but doesn't seem to do much. Any issue with using GOO GONE on the Rustolium?

Dread, Canyon and Cycle, Thanks for looking in at what I got going on. I know I'm new and really don't have much of a clue, but I appreciate the comments. Going alright so far.
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