OldTLSDoug
Forum Supporter
Well, I got a little time this morning and my friend Jim and I popped the head off of the DR-Z. It was pretty quick work we were done with the tools cleaned up in 1.5 hours. I also did a bad thing, I popped a keeper using the internet socket method. We wore safety shields and glasses, two smacks and we were clean. It was fun, but I wouldn't have tried it on a non-bent valve.
So, on to the carnage.
First we pulled the cams and the bucket of the destroyed Intake valve. It appears the springs failed, then the valve became unattached and walked around. We found all of the keeper and the pieces of the valve guide. What I think saved most of the stuff was that it caught the exhaust valve and the engine shut off immediately, and the intake valve made minor contact, but didn't fall in because of the exhaust valve. Lucky me. Note, it does not have Ti retainers as I was told. I will measure the valves later to see if they are stock or +1 mm on the intakes.
Anyway, on to the carnage....
Under the bucket view
BOTH! Springs failed!
Mr. Exhaust valve had a bad day as well...
It is amazing it did not obliterate the motor. Good thing I was at like 3k RPM.
It does have APE spring seats.
Piston was mildly abused, I think I am lucky there, that it isn't worse. You can see the pieces of valve guide sitting on the piston...
I think the head can be salvaged, it has almost a ding on the intake, but it is pretty shallow and might be fixable...
I have no clue if I can use it, it looks to be almost into the seat
The cylinder isn't hurt, but I think I will replace it, the piston, the crank, all the lower end bearings and seals. That way I will know what is in there. If I can't use my head I will buy another one. This one has my name engraved on it.
See on the right, my name is engraved
I can't get the intake valve out because it is mushroomed so badly. But I got the exhaust valve out and she is also a wee bit bent...
Well, there you go, sad but not so sad. I need to figure out what parts I need, I will miss the little bike until it is fixed. I am going to make her a big bore again, I might even put in regular stage II cams and sell my big ones. I am wondering if the springs were really right for those....
So, on to the carnage.
First we pulled the cams and the bucket of the destroyed Intake valve. It appears the springs failed, then the valve became unattached and walked around. We found all of the keeper and the pieces of the valve guide. What I think saved most of the stuff was that it caught the exhaust valve and the engine shut off immediately, and the intake valve made minor contact, but didn't fall in because of the exhaust valve. Lucky me. Note, it does not have Ti retainers as I was told. I will measure the valves later to see if they are stock or +1 mm on the intakes.
Anyway, on to the carnage....
Under the bucket view
BOTH! Springs failed!
Mr. Exhaust valve had a bad day as well...
It is amazing it did not obliterate the motor. Good thing I was at like 3k RPM.
It does have APE spring seats.
Piston was mildly abused, I think I am lucky there, that it isn't worse. You can see the pieces of valve guide sitting on the piston...
I think the head can be salvaged, it has almost a ding on the intake, but it is pretty shallow and might be fixable...
I have no clue if I can use it, it looks to be almost into the seat
The cylinder isn't hurt, but I think I will replace it, the piston, the crank, all the lower end bearings and seals. That way I will know what is in there. If I can't use my head I will buy another one. This one has my name engraved on it.
See on the right, my name is engraved
I can't get the intake valve out because it is mushroomed so badly. But I got the exhaust valve out and she is also a wee bit bent...
Well, there you go, sad but not so sad. I need to figure out what parts I need, I will miss the little bike until it is fixed. I am going to make her a big bore again, I might even put in regular stage II cams and sell my big ones. I am wondering if the springs were really right for those....
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