1978 XS400 oil change

[arm]

Hey guys, im looking to change the oil on my bike and wanted to know where I can find the oil filter and possibly the O rings. Also if anyone has a picture of where the oil filter screen is and what should be used to clean it.

as a side question, I was reading the XS400 manuals and was curious about the clutch lever, on my bike the lever is quite far from my hand (maybe the last owner bent it) and it engages weird?

to put it into reference, my previous experience with bikes is 70cc or 125cc bikes in Asia where the clutch is disengaged by fully pulling in the lever (lets call this 0%) and then fully disengaged by fully letting go of the lever (100%). on my xs400 it feels like 0% - 75% is disengaged then 75%-100% is where the clutch actually starts to do something. Does this make sense and is this normal or should I make changes?

 

[tstidham]

K&N still makes the filter and can be found at a few online retailers. Not sure on the o-ring, maybe yamaha still carries it, but I've been reusing mine, and so far no leaks.
When I got my 78, the end of the lever was definitely bent and I picked up a nice replacement from mikesxs (they also carry the filter). And it sounds like you need to perform the clutch adjustment procedure. You can download repair manuals from here and it walks you through it.

 

[arm]

So i had a question about the oil, in the manual it says SAE20w-50 and I saw a few options. The Castrol, Lucas and MotoMaster all mentioned they are for wet clutches but the Motomaster was half the cost of the others. I was a bit skeptical so I went with the Lucas oil but man was that expensive. Is there anything I should be worried about with cheaper options or was it a better idea getting the lucas oil?

 

[arm]

So i went to change the oil and I'm not sure if this is normal?

Heres a video I made of me draining the oil and inspecting the filter

video

 

[CaptChrome]

Some filter options for the XS400 SOHC: WIX 24934, NAPA Gold 4934, KN-144, Fram CH6003, Mann MH88, Mahle OX802, Purolator ML 16803

The WIX filter (and I think the NAPA) comes with new o-rings in the box. Others I don't know about. If you find them on the shelf of an auto parts store, look in the box for the o-rings. For oil that won't break the bank, the go to for vintage bikes is Shell Rotella T4 diesel engine oil. It is rated for wet clutches.

As for the oil change video - It looks like sludge and that previous owners didn't care to do basic maintenance. There are not a lot of miles on this bike, so it is far from the end of the line for it, so clean things up and run the new oil for a few good long rides, maybe 400-500 km and then change oil and filter again to flush as much of this stuff out as you can. Then resume a normal oil change interval. If it looks really bad after that, then is the time to worry.

 

[arm]

Some filter options for the XS400 SOHC: WIX 24934, NAPA Gold 4934, KN-144, Fram CH6003, Mann MH88, Mahle OX802, Purolator ML 16803

The WIX filter (and I think the NAPA) comes with new o-rings in the box. Others I don't know about. If you find them on the shelf of an auto parts store, look in the box for the o-rings. For oil that won't break the bank, the go to for vintage bikes is Shell Rotella T4 diesel engine oil. It is rated for wet clutches.

As for the oil change video - It looks like sludge and that previous owners didn't care to do basic maintenance. There are not a lot of miles on this bike, so it is far from the end of the line for it, so clean things up and run the new oil for a few good long rides, maybe 400-500 km and then change oil and filter again to flush as much of this stuff out as you can. Then resume a normal oil change interval. If it looks really bad after that, then is the time to worry.

I was able to order a Napa filter from my local Napa store so I'm just waiting for that to come in

as for oil, do you think the MotoMaster oil will be fine? and is the current oil looking decent besides the sludge on the drain plug?

I don't have any plates on my bike either so it is a bit hard to put 400-500kms on the bike, so far I've put a total of 80km on the bike

 

[CaptChrome]

as for oil, do you think the MotoMaster oil will be fine? and is the current oil looking decent besides the sludge on the drain plug?

I really don't know anything about the MotoMaster oil. For use as a flush though, it will probably be just fine. I prefer the diesel engine oils as they are most like the oil that the bike was designed for in the late '70s and '80s, but any motorcycle oil will work as long as it is for a wet clutch service.

I am not too sure about the "look" of the old oil that came out as cameras don't always give a great impression when pointed at a pan of old oil. I would have to feel it and smell it to get a good sense of what is is really like. If the stuff in the pan feels like oil, doesn't have a bunch of glitter and grit to it and doesn't smell like it has fuel mixed into it, things are probably okay.

For a hot flush of the engine, idle it to get the engine hot and ride it if you can to give it some revs and allow the gear box to work a little and then dump the oil and change the filter. Do what you can reasonably do.

I was able to order a Napa filter from my local Napa store so I'm just waiting for that to come in

Sounds good. I am hoping that it comes with o-rings as the Napa filters were being made by WIX and put in Napa packaging. I have heard that Napa changed suppliers for some of their spin-on filters though and hope our filter wasn't affected by the change.

 

[arm]

This is the product picture attached, from my knowledge, the bigger o-ring goes on the oil filter cap thingy and the smaller o-ring goes on the big bolt that holds it all together.

and I think the oil was a bit watery and smelt like gas but I'm not sure if that's just how the oil is supposed to smell. I read some other members on the forum discussing how they have gas in their engine oil and even saw a video of someone who took off their fuel tank and was able to run their bike for a decent bit of time until they realized their oil was filled with gas.

hoping that this project remains as a budget bike and doesn't end up breaking the bank

p.s quick thanks to everyone on this forum! its great to have a place where I can share my newbie question! plus there's tons of posts and info on here!

 

[CaptChrome]

and I think the oil was a bit watery and smelt like gas but I'm not sure if that's just how the oil is supposed to smell

The oil should not smell like fuel. This is a sign that the float valves in your carb bowls and your petcock are not sealing properly. This is dangerous for the engine and you should probably at least rebuild the petcock and install new float valves and seats.

 

[arm]

Its done! Today i picked up the filter from Napa and got the bike running again

I pulled out the oil screen and hit it with some brake cleaner and got a good bit of back gunk out and its nice and clean

New oil filter and new rubber o-rings

I added 2.4L of oil as advised in the owners manual, small concern though, im not sure if the dipstick on this bike is intentionally a little bent looking or if its just mine?

in the picture on the left, you might be able to see how it sort of arches near the bottom? My oil level on the dipstick is from the bottom of the dipstick, above the second line marking, and below the cylindrical part of the dipstick, so im not sure if i might've overfilled by a bit or maybe cause my dipstick is curved its reading like that?

I rode the bike after and there was a bit of smoke but I think thats cause i dropped a bit of oil on the exhaust when refilling. After ripping on the bike for a bit it felt great, although changing oil isn't really a performance booster afaik but the motorcycle felt a lot nicer to ride. Maybe it was a placebo from the work i did XD

The oil should not smell like fuel. This is a sign that the float valves in your carb bowls and your petcock are not sealing properly. This is dangerous for the engine and you should probably at least rebuild the petcock and install new float valves and seats.

I do plan to take the bike to a shop to get the carbs cleaned, the throttle takes a long time to translate to the engine so it seems like a lot of issues are pointing there. Just need to get the time to either get plates on the bike or rent something to tow it to the shop

 

[avemachina]

Congrats on getting it running! Where exactly IS the oil strainer? I've changed my oil a handful of times and not once have I found that little guy! No good photos seem to exist. Is it by the oil drain plug?

Regarding the clutch, play with how the cable is positioned--the cable routing has a huge influence on how the lever feels.

I use Castrol Actevo 20W-50 (but I'm in a place where daily temps hover around 90-102F). Seems fine and pretty widely available.

 

[tstidham]

The underside drain plug is in the middle of a rounded rectangle plate with something like 6 or 8 bolts holding it on. Remove those and pry the plate off to get to that strainer.

 

[arm]

Congrats on getting it running! Where exactly IS the oil strainer? I've changed my oil a handful of times and not once have I found that little guy! No good photos seem to exist. Is it by the oil drain plug?

Regarding the clutch, play with how the cable is positioned--the cable routing has a huge influence on how the lever feels.

I use Castrol Actevo 20W-50 (but I'm in a place where daily temps hover around 90-102F). Seems fine and pretty widely available.

I meant to take a picture for you but I kept on forgetting!

The bottom plate is what you'll see when you get under your bike and that oil screen is what you want to get it, on my bike the cover came out but the screen was no where to be found until I noticed its sort of wedged inside and has rubber legs that u can pull it from

You can see the bolts and the cover behind the stream of oil in this picture, mine is 78 xs400 and has 6 bolts on it

 

[avemachina]

Thanks so much! Didn't mean to hijack the thread, but you might be the first person who's ever actually had a picture of one in the wild.