It was fun whilst it lasted!!

[Thrasherg]

I left home at 6:00am this morning to join a bunch of friends on a practice run for the Redneck Ramble that will occur this coming weekend. Got to Jacksboro for 8:00am, said hi to everyone and then we all drove to the official starting point. Unloaded the bikes and kitted up, by 9:00am we where on the road!! About 30 minutes into the ride, I notice my headlight is not working, neither are my indicators or horn and the GPS says it's running on battery power, I figured a fuse must have blown, the bike was running great so figured I would wait for the lunchtime stop to find out what was wrong.. About another 30 minutes later and the engine locks up, fortunately I grabbed the clutch and came to an uneventful stop, but the engine would not turn over. I put it in 5th gear and was able to rotate the crank backwards and forwards but not make a full revolution, so I guess I had dropped a valve!! Bummer.. Fortunately little General (robert) came back and gave me a lift (36 miles by main road) back to my car, I then went and collected the bike and drove home. Got home at 3:00pm and started to take the head of whilst the engine was in the frame, it rapidly became apparent that this was going to have to be an engine out job!! Managed to remove the engine from the frame and then stripped it down, as suspected an exhaust valve had dropped (I am running Kibble white valves (they are 8 years old) so I guess they fatigue over time!). The head looks to have dropped off, bounced around in the combustion chamber a few times as there is some light damage to the head, but there are 5 big holes in the cylinder where the bore has smashed into the water jacket, then the piston is well mangled and lastly the con rod is bent and twisted!! Need a new crank, new barrel, new piston and rings, then need to send the head off as at least 1 exhaust valve guide is broken, I want to replace all 4 valves and get the seats in the head re-cut as the engine is quite old and it would be good to freshen it up!! This is a 2007 CRF450X that has done about 18,000 miles and was on the original crank, I just changed the piston and cylinder in December as it was starting to burn oil!! Should have changed the valves, but they looked okay to me!!

Enjoy the pics, xmas is coming early for me!! This is going to be expensive.. Any recomendations on a good shop to rebuild the crank or purchase a good replacement are very welcome, same with any recomendation on a good shop to do the head work!!

Gary

 

[garfey]

UUGLY!

 

[SL350]

Which bike? Dang sorry for you. Sure was odd how it acted like it was electric first.

 

[OldTLSDoug]

I used APE and they did a great job. Here is a link.

I had a valve spring fail in my DR-Z and it forced a head rebuild, a new cylinder, piston and crank. I replaced all the internal bearings and checked all the internals while I was there.

As I sent it to them:

What I got back (I got all new valves, new seats, new guides and had them lap the head gasket surface as well):

 

[sandsman]

Very ugly indeed.

 

[Thrasherg]

Thanks Doug, I was hoping to find a shop in Texas, but not a problem to send it to CA!! Already located a new crank, cylinder, piston and rings. Bought 4 new kibblewhite valves, so want to take the old valves out and then send the head with new guides, seals and valves to APE and have them change the guides and recut all the seats, then lap the valves and put the head back together.. might have it up and running in 2 to 3 weeks!!

Gary

 

[OldTLSDoug]

Gary, APE supplied my springs, retainers and new keepers as well. You might send the valves back and try them. I was very pleased with their work. They were busy but I think it only took a couple of weeks. Also I think they sell complete heads ready to go if you have a time crunch and the right scooter.

 

[stephensatt]

Wow! That sux! I have a jetski right now, similar problem. I am 2 rebuilt engines into it now, and it all started because a tiny piece of the spark plug broke off and wrecked the exhaust valve as it tried to clear it on the exhaust stroke. 2 complete engine rebuilds later, and its still giving me problems. These high revving Japanese engines are just too too picky, and too precise and all the aluminum parts don't hold up on the break in if you don't baby them. Its really the labor that kills you.

 

[one Wolf]

Have to ask. What was the electrics problem?

 

[Johnf3]

These high revving Japanese engines are just too too picky, and too precise and all the aluminum parts don't hold up on the break in if you don't baby them.

Well. I figure after 18,000 miles on the original crank (on an 11 year engine designed as a racing engine) it probably was broken in. I'd say that kind of longevity is outstanding no matter the country of origin.

To the original poster, I would say there is no telling what the chain of events was that caused your failure. The stainless steel Kibblewhites are almost bullet proof. If it was using oil and showing signs of needing attention, something else could have let go that got in between the valve and the piston. That is some impressive carnage. Here's to the next 20K miles, once you get it going again.

 

[WFO75080]

Call Lucky Nichols at LCS racing in Palestine. He's been around as long as oil has and not only been a racer but sponsored and built many engines for the Pro's. He's forgotten more than most will ever know. His shop has it all! Tell him David from Greenville sent you. You won't be disappointed.

 

[Thrasherg]

Have to ask. What was the electrics problem?

For the minute it seems the battery went open circuit, showing zero volts, but I dont understand why the alternator didn't keep producing voltage!! Maybe the battery went short circuit rather than open circuit and popped a fuse.. Been too busy dismantling the engine to chase the electrics but will look at it soon..

Gary

 

[Thrasherg]

Call Lucky Nichols at LCS racing in Palestine. He's been around as long as oil has and not only been a racer but sponsored and built many engines for the Pro's. He's forgotten more than most will ever know. His shop has it all! Tell him David from Greenville sent you. You won't be disappointed.

I didn't think of Lucky, he is working on a CRF450X carburettor for a friend of mine!! Will call him later this week!!

Gary

 

[Aspear]

Ouch!

Check out wrenchrabbit for a good deal on a complete rebuilt in a box, includes a new cranks. might as well replace transmission bearings while you are in there.

 

[Thrasherg]

thanks, I had never heard of wrenchrabbit before!! I have already ordered the crankshaft, piston rings & cylinder plus gasket set,it cost me $80 more than wrenchrabbit, but I have ordered genuine honda gaskets, so seem to have done okay!!

Gary

 

[Aspear]

From the one close up picture, I'm not positive that the head will be salvageable. Looks pretty ate up between the damaged valves

 

[Thrasherg]

I dropped all 4 valves last night and had a good look, the seats are not damaged (will need to be re-cut) the exhaust valke guides are both broken at the end but are easily changed and the damage on the bridge of the head between the two exhaust valves is very little and can easily be sorted out with a little effort and a dremmel!! Could have been much worse.

Gary