XR400 Seized/Blown Engine Need Rebuild Advice

[Orujo]

Hi All,
First post here and unfortunately a depressing tale of woe.

I picked up a 2000 XR400 two weeks ago. It only had 12,000 km but was a bit ropey and I probably should have walked away but I was inspired by the Internet reputation and almost cult following of the bike and reports of bullet proof engines. I assumed it just need some plastics and a touch up of the rusty bits but that the engine was sound.

I rode it about 240 km on the main road after collecting it and then have used it for commuting about 70 km a day on dual-carriageway for over a week, while I was having work done on my other bike (another tale of woe).
Once I got the hang of the kick starting procedure it started fine first time.
As I said most of my time on the bike has been about 600 km of fifth gear constant speed of about 80-90 kph commuting, which the bike didnt seem to like. I had a few offroad spins and the onlw problem was a noise when in 1s or 2nd gear and slipping the clutch up-hill or in difficult sections. I assumed this was just the worn clutch plates and added them to the list of minor repairs for my new bike.

While I was trying to get the hang of the kick starting procedure some busy-body came over and started pocking around. He spotted the breather tube comming from the crankcase and not cinnected to anything, and thought it should be connected somewhere.

• So first question: In the link below where should the end of the crankcase breather tube (part 23) be connected? The busy-body thought it should be connected to the drain tube at the bottom of the airbox (part 21). This tube was all blocked with dirt. I cleaned it out and stuck the end of the crankcase breather tube onto this end of the airbox and rode it for a bit. Later I had second thoughts, I couldnt find much about it in the Honda Workshop Manual so I just disconnected it from the airbox and left it hanging there. Could this have caused my major problems:

OEM Motorparts - Honda - XR400R - 2000 - AIR CLEANER

The bike soon developed a knocking noise on the left side of the engine, noticable especially when started first. It also seemed a bit noisier when warmed up and running (fifth-gear motorway 80-90 km per hour). Because I was not that familliar with this bike and more worried about my other bike, I assumed everything was ok.
A few days ago on my way home, just at the end of my commute I accelerated up to around 100 kph to over take a few cars, shortly after the engine started to die, clutch in I pulled over while going down through the gears trying to bump start if before she stopped moving. When I eventually stopped, I went to kick it over and the kick starter would not budge. She would not bump start in any gear, wheel is just locked once the clutch is let out.
My apologies for this long first post, my fundamental questions are:

• When the kick starter wont move or the wheel turn in geer does this definitely mean a seized engine?
• Any take a stab at the cause, piston, cam chain?
• I know the solution is to open the engine up and look for the problem but this is something I would not be able to do myself. Does it sound like it is worth fixing?
• If it is just a top end rebuild can someone give me a shopping list of the parts that I sould be replaced for a stock rebuild (no big bore) and what might all this cost and any reccommended suppliers.
• Hoping/Assuming this is just a top end rebuild, any idea roughly how many hours labour would it take to strip it down, get it un-seived, clean her up and put back together with the new parts?

Any help, advice or comment you could provide would be much appreciated as I really want to get here back running without breaking the bank.

Thanks in advance.

[scotsy]

Firstly, i'm really sorry to hear about the demise of the engine

but.........

Do you really think that sustained high speeds and ignoring 'knocking noises' would result in any other outcome?

Was the oil level low? (when did you last check it?)

Was the air filter clean and oiled?

The engine is probably fooked!!

It could be related to clutch plate failure and the errant pieces getting jammed somewhere....but i doubt it and you'll never know unless it is taken apart and the damage assessed by someone

Good luck
ian

[Esoteric1]

Well the first bit about the breather pipe is no problem as it does connect to the air box and the other end down towards the floor connected to nothing.

12,000 KM is nothing. I heard someone had 30,000 miles on there's and it was still going strong.

Your engine sounds as though is has seized. You do ride it fast!
I don't take mine over 50 MPH, the rear cog isn't geared up for road use.
The problem with these bikes is that people use them off road, replace the clocks as sell them as having less mileage than they really have.

The other issue with theses bikes is that you need to keep on top of the oil changes, and the oil in theses bikes needs to be changed in a specific unique way.
You will need the manual.

So people run them down not knowing how to maintain them properly, put the clocks back on and sell them.



Yeah so sounds like an oil issue to me!

[jasonbc]

Bottom line here is if you can't move the kick start the engines not moving, the only way to find out the problem is to open it up, they are easy to do and cost will vary depending on what you find wrong with it, what ever you do if it is th eworst case scenario don't put a 440 kit on it as a cheap fix as the motors cant cope with them.













This little problem cost me around £400 in parts to put right, and i did all the work

[jasonbc]

The other issue with theses bikes is that you need to keep on top of the oil changes, and the oil in theses bikes needs to be changed in a specific unique way.
You will need the manual.

!

When was the last time you check all 3 oil filters on the bike ? !!!

[ade]

I'm a firm believer in mechanical paranoia ,if it dont do as it says on the tin,investigate...

[Esoteric1]

I have checked two of them but I have now learned of a third one roughly located near the drain plug.
Think I will check that next time.

I was wondering jasonbc, I will doing a full rebuild my self soon so could you possibly give me a list of bearings and any other parts I will need and roughly how much they will cost.
My knowledge goes as as far as big end bearing, crank bearings, small end bearing and piston kit. I had a cylinder re-chromed once by an engineer who lives near me so that won't be an issue if it needs doing. And how difficult is the crank case to split?
Thanks!

[jasonbc]

I have checked two of them but I have now learned of a third one roughly located near the drain plug.
Think I will check that next time.

I was wondering jasonbc, I will doing a full rebuild my self soon so could you possibly give me a list of bearings and any other parts I will need and roughly how much they will cost.
My knowledge goes as as far as big end bearing, crank bearings, small end bearing and piston kit. I had a cylinder re-chromed once by an engineer who lives near me so that won't be an issue if it needs doing. And how difficult is the crank case to split?
Thanks!

The 3 oil filters are the main filter, remove the righthand engine cover at th ebottom of th ecrankcase is a bolt with 10mm head (i think) undo it and a screen about 5cm x 8cm will come out the other is at th ebottom of the frame remove the oil hoses and them you have the big nut undo that and the strainer will come out.
I'll try and find the receipts for the bits i bought and share them up here

[Esoteric1]

K. Thanks!

[Pieeyedpiper]

Well the first bit about the breather pipe is no problem as it does connect to the air box and the other end down towards the floor connected to nothing.

Is that right? The curved top end of mine (250) just hangs over the top sub-frame mounting bolt.

Which is the air box connection it goes on ?