XR400 Seized/Blown Engine Need Rebuild Advice

[Orujo]

Jasonbc, cheers for digging out all that info. Hopefully that will be my benchmark worst case scenario and I wont have to go that far! Fingerscrossed.

On the crankcase breather discussion, 416cc's comments got me thinking. That day when I was trying to start my bike and a "know-all" busy-body came over pooking about, he connected the upper end of the breather tube to the pinch-pipe at the bottom of the air-box that 416cc mentioned. There had been a pile of sh!t/bog cacked inside this pinch pipe.
I rode the bike for about 40 minutes before I stopped and thought about what he had done and decided to disconnect the tube from this airbox pinch pipe.
Before this day I had not noticed any abnormal engine noise aftwards I did and the end result was my seized engine.

• So, does anyone think that crud could have entered the engine via the crankcase breather tube and caused the seizure?
• How much crud does it take to seize and engine?
• And if this was the cause, would it do catastrophic engine damage or something that is repairable with minor surgery (i.e. cost).

Again thank you all for your helpful comments to a new site user, im very impressed and grateful.

[Esoteric1]

Possible but not likely, as an indicator I would check this easily accessible oil strainer bellow. {Top photo}
There are 3 oil filters in these bikes and two of them are strainers.
When replacing this make sure the flex pipe doesn't bend as you tighten back up.

[Pieeyedpiper]

The breather pipe is connected to the air box, and the other end just hangs loose towards the floor.

Any way how the heck have you got your upper hose onto the airbox drain tube? The outlet is lower than the "T" on the breather hose. You must have one hell of a kink in the hose!

[Esoteric1]

No idea, I havn't even lookued at it properly. All standard on mine.

[Pieeyedpiper]

Hardly.

[Orujo]

Hi all,
By way of update. Well there is no update.
I am trying to get a bit of cash together and hope to get the bike to a mechanic in a week or so to diagnose the problem, then ill order the required parts (hopefully not too many) and if all goes well I might be back on the trails some time in October.
Ill post back here when I have some real updates.

[Orujo]

All, the news is bad.
The engine is completly wrecked. It is not easy to post this and very embarassing.
It seems the engine was basically running dry.
I cant explain how this happened, I only had the bike a week and a half, the seller said it had had a full service, I checked it after a few days and there was oil on the dip stick but it is possible I didnt check it correctly. It is possible it didnt get that full service and was running on ****ty years old oil. I cant believe that it burnt 2 liters of oil in a week and a half, especially as there was no trace of black smoke from the exhaust.
Either way, I messed up, should have walked away, should have changed the oil straight away. This is the first bike ive bought privatly and its been a disaster, put me off the whole process. Now I need a way out and I need advice.
The Damage:
The engine is completly trashed, the surface of the rocker arms is all softened and the edges are all burred and rough. The piston rings have disintegrated and are non existant. The barrel is badly scorred.
Thats as much as I know.
What next:
The guy that took apart the top end thinks its very bad based on the state of the top. He is not in favour of a rebuild as he reckons it will cost more than the bike is worth. He reccommends I just wait for a replacement engine to show up and a swap.
Problem is I havent seem many full engines around and the risk that the new engine is toast and I am back the square one.
Parts wise I reckon I need at least:
Rocker arms, cam shaft, Piston&rings, cam chain&tensioner, barrel or new sleve, crank, connecting rod, oil pump, gaskets and bearings.
This is coing to cost a lot of cash.
There are a few bits on ebay:
Top end:
Honda XR 400 XR400R Fully Reconditioned TOP END on eBay (end time 28-Sep-10 16:59:28 BST)
Crank:
honda xr 400 98 crank amazing bikes on eBay (end time 17-Oct-10 10:59:25 BST)
Oil Pump:
HONDA XR 400 OIL PUMP on eBay (end time 03-Oct-10 12:01:59 BST)
The above 3 items will come to £400 alone.

So what do people think, should I start buying up bits and pieces from ebay or should I wait for a full engine to show up, should I check the States? Are there any other engines I could fit, drop to 250cc if one shows up?
Another option I was conserding was to scrap it (I might get €400 maybe a bit more if I trailer it to the UK) or trade it in for a runnung enduro bike from a dealer. This might mean I will spend more money but loose less on the XR and get back on the trails sooner. The problem is I want a long stroke, lower maintenance bike like the XR400 or a DRZ as opposed to a higher maintanence newer bike like a CRF or a KTM, but there arent any XRs or DRZs in dealers in Ireland.

Any ideas please, Im a bit depressed with the whole think.

[jasonbc]

All, the news is bad.
The Damage:
The engine is completly trashed, the surface of the rocker arms is all softened and the edges are all burred and rough. The piston rings have disintegrated and are non existant. The barrel is badly scorred.
Thats as much as I know.
.

The barrell not a huge drama you can get a new liner pressed into it, the guy that does it down here told me about £85 including the liner but i didn't find out about him until after i had rebuilt mine. Throw a set of rings and a piston in probably about another £100. Get it from David Silver and ask for the 3-4 week wait price as that wil be alot cheaper than over the counter price. Can't advise on any other damage as there not much to go on. Give John a ring at XRSTUFF and see if he's got a secondhand head complete with rockers he does break xr's up there worth a shot

[Orujo]

The guys that took it appart for me, feel there is potentially too much work. The parts could be expensive and then as I wouldn't be doing the work myself there would be a substantial labour bill as well.

I had hoped this thread would turn into a success story and I could get it running aginn but I am sorry to say I am giving up on the XR and think the best option at this stage is to pull the plug on it.
I am going to advertise it as a project bike and hopefully try and get some of my money back. My only lifeline is if I could find a decent engine for it in the mean time I would love to hold on to it.

So if anyone is interested in buying the bike, for parts or to do it up themselves, please let me know. If the price was right I could get the bike to the UK.
Or if anyone knows of a decent XR400 engine, give me a shout.

Thanks again to all for your advice.

[rossirossi]

can you put some photos up? I could be interested if your able to get it to the england. Cheers