New (to me) XR400

[Twiggy0ne]

So let me start by saying hello! This will be my first post to the ThumperTalk forum, and I'm glad to be joining the community. I discovered this forum a few weeks ago while doing some research for a bike and it has since become a valuable source of information.

A little about me: I grew up riding motorcycles, it was always a passion I shared with my dad. I had a number of bikes over the years, but fell out of it in my late-teens and have haven’t owned a bike in 10 years or more. I still love to ride, and any chance I get I’m always keen.

And now for the bike: I’ve been casually shopping for a while now, with no real intention of buying anything this year, but maybe in time for next summer. I had been keeping an eye on local online classified listings, and a couple of weeks ago a listing popped up for a 1999 XR400R with a seized motor. Everything else about the bike looked like it was in relatively decent shape and the price was right, so I bought it. I don’t have a whole lot of experience wrenching on bikes, but I always found it interesting. I’m a carpenter by trade so working with wood is my thing, motors have always been a bit intimidating, but I’m always up for a challenge. My plan for the bike is to take my time dismantling and re-building it, and if all works out have it up and running by next spring.

So the story from the guy that sold it to me was that the bike was crashed on a water crossing and swamped. They drained it out, pulled the plug to kick the water out, but couldn’t manage to start it. And so it sat. He said it had been there since last summer, but who knows. When I picked the bike up, the motor wouldn’t turn over. Someone had pulled the carb right off the bike and started to take it apart.

Here's what she looked like when I brought her home:

Let the fun begin!

[WWalker]

You will def have fun tearing into that bike...have fun! Good choice of ride. Maybe a dumb question but why not just buy a bike that runs? Thankfully this site exists to help guys like me who need it. Good luck and hope you get it running soon.

[GU520]

Congrats with the new bike. Google for a XR400 workshop manual, one is floating around on the internet, and is very helpful when you tear into the engine (obviously).

And remember that everyone loves a good rebuild thread with lots of pics....you would get lots of tips... just had to mention that....

[crazyfast]

Carpenters are all the same . We buy crap cheap because we can fix anything no matter what the cost. Im on my forth xr4 that came to me in that condition.You'll figure it out, the engines are pretty simple. I see your over in Canada,

I'd start with the top end on the bike and pull the head then jug and see what is bound up.

[michigan400]

Just hope the water was removed from the bottom end.

[Dansmith1965]

Normally a seized motor wouldn't scare me a bit, but a seized motor with water does. I would definitely tear into the top and bottom and see what you are up against before buying any parts.

[Motosprtman]

flush it, maybe already done this and it is messy with an engine still in the frame. First drain it from the oil drain plaug followed by good ol gasoline poured through the oil filler hole - this works best if you also have the engine side covers removed. pour gas through until that is all that is coming out, then leave open and let dry. You can also flush the top end the same way, remove the valve covers and using a small container such as a sequeezablke bottle with a short hose = and the spark plug also removed - squeeze gas into all four holes and continue until all you get is clean gas coming out, don't be afraid to use a guantity of gas in doing the top and bottom end, a gallon or two should suffice.

Once dry, close it back up and refill with oil, use a mix of kroil and ATF down the plug hole let it sit. after a day or so place a socket and breaker bar 1/2 in drive on the flywheel and start rocking it back and forth until it breaks free, you can also use a leverage bar but be carfeful not to apply ot much force and snap off the flywheel bolt.

If it is still stuck. Time to remove engine and do a rebuild. But at least the flushing is done!

[Twiggy0ne]

You will def have fun tearing into that bike...have fun! Good choice of ride. Maybe a dumb question but why not just buy a bike that runs? Thankfully this site exists to help guys like me who need it. Good luck and hope you get it running soon.

I'm in the same boat, I'll need all the help I can get on this one! I bought the bike as a project to learn on, and the price was right ($800). With the reputation the XR400s have for reliability and the availability of parts, I figured it would be a good place to start.

Congrats with the new bike. Google for a XR400 workshop manual, one is floating around on the internet, and is very helpful when you tear into the engine (obviously).

And remember that everyone loves a good rebuild thread with lots of pics....you would get lots of tips... just had to mention that....

That's actually how I found this site in the first place. I searched for a link to the manual and found a bunch of references through TT, along with ample rebuild threads. I'm amazed at the passion people show for their XRs!!

Carpenters are all the same . We buy crap cheap because we can fix anything no matter what the cost. Im on my forth xr4 that came to me in that condition.You'll figure it out, the engines are pretty simple. I see your over in Canada,

I'd start with the top end on the bike and pull the head then jug and see what is bound up.

I certainly hope I can wrap my head around fixing this one. I usually stick to restoring furniture and old woodwork, so this is a welcome new challenge.

flush it, maybe already done this and it is messy with an engine still in the frame. First drain it from the oil drain plaug followed by good ol gasoline poured through the oil filler hole - this works best if you also have the engine side covers removed. pour gas through until that is all that is coming out, then leave open and let dry. You can also flush the top end the same way, remove the valve covers and using a small container such as a sequeezablke bottle with a short hose = and the spark plug also removed - squeeze gas into all four holes and continue until all you get is clean gas coming out, don't be afraid to use a guantity of gas in doing the top and bottom end, a gallon or two should suffice.

Once dry, close it back up and refill with oil, use a mix of kroil and ATF down the plug hole let it sit. after a day or so place a socket and breaker bar 1/2 in drive on the flywheel and start rocking it back and forth until it breaks free, you can also use a leverage bar but be carfeful not to apply ot much force and snap off the flywheel bolt.

If it is still stuck. Time to remove engine and do a rebuild. But at least the flushing is done!

That's a great idea, actually that was going to be my first question: how to remove the old oil without running it through the engine. I dumped some anti-seize oil into the cylinder and let it sit for a few days. After a bit of persuasion, I managed to get the crank to turn. I followed the Honda manual in tearing the top end apart and this is what I found.

Not too bad so far... until the piston. I could see the rust and crap built up on top.

Pulled the cylinder jug to get a look at the inside and see what damage the water has done:

And the bottom:

I sent the whole top end to a machine shop for inspection. I don't have the tools or ability to check the camshaft, lifters and valves for wear so I figured I would leave it to the professionals. They're also going to bore the cylinder out for me.

The condition of the cylinder jug got me worried about how much water had gotten into the crankcase and wreaked havoc. How can I go about checking this out? From what I can see from looking down into the crankcase, there is no visible rust or damage, and the oil looks relatively clean (not milky). I'm going to flush it out with gas tomorrow, but a couple questions: which covers should I remove to flush it out, and what should I be watching for? Also, how should I lube the crankcase after flushing? Presumably throw some more cheap 10w40 in?

More pics to follow tomorrow.

Thanks for all the help!

[GU520]

Now the beauty of the XR4, unlike modern machines, is that you have a steel sleeve in the cylinder. It can be bored out.

Personally, I would start by removing the right hand (clutch side) engine cover and take a look.

[RBRXRMAN]

Congrats Twiggy. Welcome to the XR world. You made a great choice.

There are some widely known issues with the XR400 but not too many and the ones it does have a fairly easy to overcome.

There was a bit of a shifter shaft weakness that Honda re-engineered in 1998 I think so yours may not have that issue being a 99. The other nuisance is coomon to all and that is a lack of lubrication on the rear swing arm bearings. You may want to look into that while your cylinder is being worked. Also check the lube on the fork steering head bearing. Since it has been underwater you may find some interesting issues there.

Best of luck!

[crazyfast]

Don't hesitate, pull the engine and tear it down. At this point it makes sense to clean every part of that engine. Rust on bearings is bad bad bad, they have to be replaced.

[WWalker]

Thanks for the update pics! I love to see a project in the works. You got an $800 learning experience....it's worth it. I purchased an XR200 for $200 last year...it was completely in pieces...I purchased it only to see if I could put it together and get it running. Well....I'm still working on it. But I have learned a lot about bikes. Good times, man....good times. ?https://www.thumpertalk.com/topic/968120-purchased-an-02-xr200-in-pieces-never-built-a-bike-before-am-i-crazy-i-will-need-help/page__hl__%2Bpurchased+%2Ban+%2Bxr+%2B200+%2Bin+%2Bpieces

[crazyfast]

Don't hesitate, pull the engine and tear it down. At this point it makes sense to clean every part of that engine. Rust on bearings is bad bad bad, they have to be replaced.

Give me a PM if you need engine parts, I have a boat load .Across the river, Ann Arbor area

[Twiggy0ne]

Don't hesitate, pull the engine and tear it down. At this point it makes sense to clean every part of that engine. Rust on bearings is bad bad bad, they have to be replaced.

I was hoping to avoid tearing the bottom end apart, but I think you're right. At this point it's really not a bad idea. It would be a complete waste to rebuild the top end and get it back together to find out the bike is just going to tear itself apart on startup. Sounds like that lower engine mount can be a bit of a bitch, what is the easiest way to free that baby??

Thanks for the update pics! I love to see a project in the works. You got an $800 learning experience....it's worth it. I purchased an XR200 for $200 last year...it was completely in pieces...I purchased it only to see if I could put it together and get it running. Well....I'm still working on it. But I have learned a lot about bikes. Good times, man....good times. ?http://www.thumperta...200 +in +pieces

I read through your thread, sounds like you have an interesting project on your hands. I'm sure I'll learn a lot along the way. Is your bike up and running yet?

[WWalker]

I read through your thread, sounds like you have an interesting project on your hands. I'm sure I'll learn a lot along the way. Is your bike up and running yet?

No. I got it all together and running but did not get to fine tune it b/c of issues with the shifting. Look at post #98 in the thread.

I purchased another engine case a few months back but have not had the time/desire to work on it. I will tear into it this summer I think....get it all apart (split cases again ) and see if that fixes it. I also need to look at the kickstart mechanism....might need fixing too.

I def learned a lot!!! It was no problem with me worrying about it b/c it's a $200 bike that I've maybe put $150 into. I sold some other random motorcycle parts to help finance the continuing of this project.

It's kinda hard to get motivated because I have a perfectly fine running XR400 that I ride. Plus I am currently dumping money into my GSX-R 750 track bike. ?