1st post: just acquired XS400

[GuyS]

Is your front sprocket held on by two 10mm bolts and a “lock washer” like mine? If so, is there a little play between the sprocket and the transmission spline. Mine is a Maxim so may be different. Yours does look in quite good shape. I am surprised at the rust you talk about.

 

[Lemonysword]

Is your front sprocket held on by two 10mm bolts and a “lock washer” like mine? If so, is there a little play between the sprocket and the transmission spline. Mine is a Maxim so may be different. Yours does look in quite good shape. I am surprised at the rust you talk about.

Mine is a single large 32mm (I think) nut with the little bent up flange to lock it in place. I got it tight enough that there is no play with the sprocket itself.

In regards to the rust, none of it is severe, but it is basically everywhere. I spent about an hour today using the wet aluminum foil trick to remove a good amount of it and while it won't repair the damage, it looks much much better. Pics here are some before and after.

One of the mufflers has a big quarter sized hole in the chrome so nothing I can do about that. Fortunately it's on the bottom and I didn't even know it was there until I felt it while scrubbing

 

[GuyS]

Mine is a single large 32mm (I think) nut with the little bent up flange to lock it in place. I got it tight enough that there is no play with the sprocket itself.

In regards to the rust, none of it is severe, but it is basically everywhere. I spent about an hour today using the wet aluminum foil trick to remove a good amount of it and while it won't repair the damage, it looks much much better. Pics here are some before and after.

One of the mufflers has a big quarter sized hole in the chrome so nothing I can do about that. Fortunately it's on the bottom and I didn't even know it was there until I felt it while scrubbing

Oh, your front sprocket is different than mine, and a more common way of holding the sprocket to the transmission shaft. Mine is a spline type on the shaft and in the sprockets center, so I suspect that design “intentionally” is not a locked on tight method of holding the sprocket in place. Removing the (2) 10mm bolts makes it easy to slip the sprocket off of the splined shaft. I’m guessing that allows for the sprocket/chain to account for slight misalignments. kind of like the output shaft on a car. But unfortunately,…… I’m not sure if that the correct reason for the setup or not!

 

[Lemonysword]

Went for a test ride last night. Didn't make it far before the bike died. Pretty sure it was the battery so I walked it home and put it on the trickle charger - a challenge since I still haven't been able to get the left side of the seat to unlatch.

Today it started right up, idled at 1200rpm (I'd fiddled with the idle screw yesterday) and rode it around. Didn't make it super far before it started choking up and required more and more throttle to idle until it died. I poked around and turned the petcock to prime and watched fuel flow through the filter. 20-30 seconds of prime and it fired right up. Hmm. rode around a bit more and it happened again. So the vacuum petcock is apparently shot. Next step now is to drain the tank, pull the petcock and diagnose, probably will be worth my while to just order a rebuild kit for it.

 

[GuyS]

Does it have “prime” on the fuel cock? It may bypass the vacuum issue. I’m not sure cause I haven’t got that far yet but I just watched a video on Youtube …….https://youtu.be/6hO0TAi_ATk?feature=shared

 

[Lemonysword]

Yeah it works on prime just fine, but I am not familiar enough with vacuum peacocks to know if this is a normal failure that would be repaired with a rebuild kit or if there's something more going on.

My ural had a vacuum petcock and when it started to go bad, it would allow fuel to flow in the ON position when the engine was off, leading to my carbs puking gas after every ride. I replaced it with a standard petcock and it's been fine since (oddly I leave that petcock ON all the time and it doesn't leak gas).

 

[avemachina]

The other things to double-check is to make sure the vacuum hose is secured/has a good seal to the intake boot, and that the other side is capped off.

Also the gas cap seal--see if anything changes if you leave the gas cap open.

 

[Lemonysword]

The other things to double-check is to make sure the vacuum hose is secured/has a good seal to the intake boot, and that the other side is capped off.

Also the gas cap seal--see if anything changes if you leave the gas cap open.

I got my seat off today and pulled the tank. The vacuum line is a few inches longer than it needs to be and I'm fairly certain that it may have been bunched under the gas tank and kinked up. I was very careful aligning it when I put the tank back on this time. Its raining now so I don't feel like a test ride, but I will probably take it out later today and see if that resolved it.

I also removed the brackets for the engine guard from the front engine mounts and cleaned up some more rust from the chrome.

I am debating on whether I want to pull the forks apart today. I don't have new fork oil yet so I wouldn't be able to ride at all until I get some

 

[GuyS]

I got my seat off today and pulled the tank. The vacuum line is a few inches longer than it needs to be and I'm fairly certain that it may have been bunched under the gas tank and kinked up. I was very careful aligning it when I put the tank back on this time. Its raining now so I don't feel like a test ride, but I will probably take it out later today and see if that resolved it.

I also removed the brackets for the engine guard from the front engine mounts and cleaned up some more rust from the chrome.

I am debating on whether I want to pull the forks apart today. I don't have new fork oil yet so I wouldn't be able to ride at all until I get some

If I have any problems with my petcock I’m going to convert to manual. I think I know why manufacturers put vacuum systems in, so you can’t forget to shut the gas off. But that’s a problem because you always have to rely on a bunch of little parts in the pet cock to be operating to shut the fuel off. There’s no other way to shut it off. That’s especially an issue with old carbureted bikes like ours If they do leak, a failed petcock could potentially flood over into the engine. I think I could get into the habit of turning off the fuel manually.
I’m going to be doing my forks to and am interested in your progress!

 

[Lemonysword]

If I have any problems with my petcock I’m going to convert to manual. I think I know why manufacturers put vacuum systems in, so you can’t forget to shut the gas off. But that’s a problem because you always have to rely on a bunch of little parts in the pet cock to be operating to shut the fuel off. There’s no other way to shut it off. That’s especially an issue with old carbureted bikes like ours If they do leak, a failed petcock could potentially flood over into the engine. I think I could get into the habit of turning off the fuel manually.
I’m going to be doing my forks to and am interested in your progress!

We had a tornado miss us by a couple miles this morning but it's nice out now, so I just rode around the block for 20 mins. No issues, so it seems my original assessment that the vacuum line was simply kinked was correct. Unfortunately when I had the tank off yesterday, I decided to see what I had set the air screws on the carbs to. I lost count because I was expecting 1 1/4 turns and it was more than that. I reset them to 3 turns out which I think is close to where it was, but ultimately I'm not entirely sure. I believe the manual states 1 1/4 turns but many on the form say 3 to 3.5. It seemed to be hot quickly but in reality I have such little experience riding normal motorcycles that I don't know what it should feel like. Since it's hot I'm going to change the oil. It only has like two miles on it despite being 5 years old, but I figure there's probably some gas and crap in it.

I'll make sure to take plenty of pics for you when I do my forks. I watched a YouTube video the other night that goes along with the manual and typed out a step by step guide from the video

front fork removal:

• loosen 14mm pinch bolt
• loosen phillips head screw above (oil drain)
• remove 2x 14mm caliper bolts
• 22mm socket on axle bolt right side
• remove axle and front wheel
• remove cap for axle clamp on left side
• loosen 6mm bolt in bottom of fork (use long screwdriver to connect forks for leverage)
• slide off fork cover
• remove retainer ring with flathead
• big flathead to remove fork seal (set on ground for leverage)
• rub suspension fluid around outside of seal
• put rounded edge of metal spacer down, seal on top, hammer seal in place, reinstall clip
• sand copper crush washer on 400g sandpaper on flat surface doing figure 8
• slide fork cover back on, wriggle around seal
• install 6mm bolt
• loosen upper bolts on tree
• remove foirk cap w/ flathead
• apply downward pressure with big phillips and remove snap ring
• remove spring
• add 142cc 20wt fork oil

reinstall axle - install bolt but dont torque once axle pulled through tighten 14mm bolts to 14 ft/lb tighten axle nut to 70 ft/lb brake caliper 25 ft/lb
10mm for brake line is 10 ft/1b

 

[Lemonysword]

How to replace the shaft seals and fork oil on an XS400




I put the bike on a downslope on the center stand so the front wheel would be off the groubd



Loosen but don't remove the 14mm pinch nuts. I also loosened but didn't remove the JIS/phillips screw above it.



Remove the 2x14mm bolts holding the caliper on, then remove the cotter pin and 22mm castle nut on the axle.



Support the wheel with your foot, pop the axle from the right with a rubber mallet to push it out. Remove the wheel



Use a 6mm Allen wrench to loosen the bolt holding the fork sleeve on



I has to use an extension on the right side. Again I did not remove the bolt yet, just loosened it while the fender is keeping the forks together for better leverage.



With both 6mm hex bolt loosened, I removed the 4x12mm fender bolts and removed the fender, then removed the left sides 6mm bolt. Make sure you have a drain pan underneath the forks at this time, because oil gushed out. I took the copper washer off and ran both sides across 400 grit sandpaper laying on a level surface. This helps even it out so it can act as a gasket when installed and tightened.



Fork cover removed. Removing the old shaft seal was a pain in the ass. First use a flathead to remove the little clamp. Then, brace the bottom of the fork cover on the ground and use a big flathead as a lever. I focused on one side and eventually it came out, but it took a while. The right side one was even worse.



This metal washer thingy is below the shaft seal. It just drops out. I cleaned it up and put it back, rounded side (pictured here facing up) goes DOWN when installed back into the fork cover. I rubbed a little bit of oil around the outside and inside of the new fork seal, reinstalled it, and popped the clamp back in.



Instead of reusing the ancient, cracked dust covers, I installed these gaiters instead. I need to put a hose clamp across the top but I'll do that later. I might even just zip tie it.

At this point, the fork cover just slides back up the fork, then reinstall the 6mm hex bolt. Once I had both hex nuts installed loosely, I put the fender back on (loosely still). With the forks more or less parallel, I tightened the 6mm bolt. I loosely installed the 14mm pinch nuts, then propped the wheel up in my foot, making sure the speedometer was oriented properly, slid the axle through. Tighten the pinch bolts to 14 ft/lb, then tighten the axle castle nut to 70 ft/lb.



At this point I did the brake pads. This pic was just for reference on their orientation. The caliper honestly needs to be rebuilt, but I don't have a kit for it yet, so once the new pads were installed I put the caliper back on and tightened the 14mm caliper bolts to 25 ft/lb

I think it looks pretty sharp with the gaiters. I'm taking a break for lunch then putting the new oil in. Total time so far is just under two hours.

 

[Lemonysword]

Wow opening the tops of the forks was a pain. Popping the handlebars off helped a lot



Loosen the 12mm pinch nut here and use a flathead to pop the plastic cover off



Push down with a big Phillips screwdriver then pop the circlip out. This is a pain in the ass because you are fighting the tension the entire time, but the technique that worked for me was to use a little pick, stick it behind the TOP of the circlip and just push it out a bit from its slot, then I releases pressure on the Philips screwdriver to let the piston push up and force the end of the clip out of its slot. Then I just pushed down on the Philips again and worked my way around the circlip with the pick until it popped out.



Then add 142cc of 20wt fork oil and reverse

 

[GuyS]

NIce write up and helpful photos Lemonysword. That will be one of my next tasks to do!

 

[avemachina]

Nice job on getting all the fork parts freshened up! The top of the forks are a nightmare; mine needed new springs and I had to get them in a vise and use a jaw puller against it to get the circlips back in. Totally worth it, but they better not need to be replaced anytime soon.

 

[Lemonysword]

Nice job on getting all the fork parts freshened up! The top of the forks are a nightmare; mine needed new springs and I had to get them in a vise and use a jaw puller against it to get the circlips back in. Totally worth it, but they better not need to be replaced anytime soon.

Yeah it was a pain. I followed this video and did it with the forks still in the bike. Basically I stuck the Philips screwdriver into the indent on the plunger and then leaned on the screwdriver, then used a pick to move one end of the circle out of its notch, then eased up on the Philips. The plunger lifted up and pulled half the clip out. Added pressure again and used the pick to pull the rest of the clip out. Putting them in I leaned on the Philips again, then used my fingers to pinch the back half of the clip into the notch, then the pick to feed the rest through. I think my springs are good, I took it on a 6 mile ride and it felt nice.

I think the gaiters look awesome. I've since secured them with some black zip ties on top.

I would like to keep this bike original, but I've also been considering swapping the handlebars with something that look a little better. Do any of you guys have a suggestion?

 

[avemachina]

I've got gaiters on my bike too, and Emgo KZ bars. The ergonomics are perfect for me (but I'm 5'6 and have the short-arm long-leg power combo going) and it looks pretty sharp.

I changed the mirrors and some of the luggage since this photo, but you get the idea.

 

[Lemonysword]

I've got gaiters on my bike too, and Emgo KZ bars. The ergonomics are perfect for me (but I'm 5'6 and have the short-arm long-leg power combo going) and it looks pretty sharp.

I changed the mirrors and some of the luggage since this photo, but you get the idea.

Beautiful bike. I know they suck compared to disks, but drum brakes on the front look so damn good.

Was white a factory color or did you repaint it?

 

[avemachina]

Thank you! It's a repaint; it was originally Catalina Blue but I just really hated it. The new color is just rattlecan Duplicolor with some 2K epoxy clearcoat.

 

[Lemonysword]

Thank you! It's a repaint; it was originally Catalina Blue but I just really hated it. The new color is just rattlecan Duplicolor with some 2K epoxy clearcoat.

The white looks great.

The paint on my bike is pretty beat up and I will likely repaint it at some point. I might pay someone to do it though, my experience painting a Suzuki gas tank was less than ideal and it came out pretty mediocre.

 

[GuyS]

I've got gaiters on my bike too, and Emgo KZ bars. The ergonomics are perfect for me (but I'm 5'6 and have the short-arm long-leg power combo going) and it looks pretty sharp.

I changed the mirrors and some of the luggage since this photo, but you get the idea.

Wow that bike looks great!