Greetings all,
Just thought I'd give you all a quick run down on my recent engine rebuild.
As you may or may not have read in my last ride report, my 2004 550 just quit one day while I was riding it, at low rev's and in a very good location.
The cause turned out to be a broken exhaust side valve spring, right near the bottom that resulted in it letting the valve hang about 1mm, so no contact with the piston, very lucky indeed. This was not discovered until I had pulled the motor and taken in to my local shop, where Brett found the problem right away. He put a leak down tester on it and, with the use of some cool looking needle nose pliers, pulled the valve back up so it seated. The leak down tester showed about twice what it should have read, so I just decided that with 220 hours on the motor, to just pull it apart and go through it.
After Brett had pulled it apart he gave me a call to come over and have a look at what he found. Upon arriving at the shop he just looked at me and started laughing and asked me if I had been changing the oil every 5 minutes? He said it looked like he had pulled apart a brand new engine that someone had splashed a little new motor oil on. He said that, with the exception of a couple things everything was perfect, main bearings, trans bearings, big end of the rod, small end rod busing,etc..... Needless to say I was happy about that.
Here's what he did find:
Left side crank main seal was in two pieces.
Cylinder and piston and 4 small scratches below the rings.
Rings were at half wear tolerance, ie end gap measurement.
Intake valves were worn, not too bad but recc. replacement.
Cam chain was worn out. This was the DID that I had just put in, only 40hrs on it. And it was replaced with a new stock unit.
He also found that the crank had a slight amount of run out top to bottom, .004" I believe, and he corrected that as well.
Everything else was in stellar condition. The piston was unbelievable, no scuffing on the skirt, all original machine marks were still visible. Only the small scratches were evidence of any wear.
Brett did a small amount of clean up work on the ports, removing some casting lines and matching the ports to the seats. He also matched the exhaust ports to the headers themselves.
So, now th motor has been re assembled with a new cam chain, rings,(the oil ring by the way is the same as the 950), seals and gaskets, new intakes, new valve springs. All that is left now is to put it back into the bike and break in the new rings.
I had originally intended to take it apart at 150 hours, but, nothing appeared wrong so I just kept riding it. I did have to change the rockers as the exhaust follower had bitten the dust. Then decided to try and go to 250 hours before the tear down, and I almost made it. All in all not bad in my opinion. I'm no hot shoe, but, I do run the motor, pretty hard sometimes when I'm racing, and to have it in this condition when it came apart is just outstanding!!
Brett had a good comment when I told him that I changed the oil after every time I rode it, and that I made sure that the oil never came out black. He said "Oil is cheaper than Metal". I have to agree, as I cannot imagine how much it would have cost if something had failed and torn up a bunch of other stuff.
My hat is off to Cheeseberger for his 10K miles and 349 hours!!
Dale
Just thought I'd give you all a quick run down on my recent engine rebuild.
As you may or may not have read in my last ride report, my 2004 550 just quit one day while I was riding it, at low rev's and in a very good location.
The cause turned out to be a broken exhaust side valve spring, right near the bottom that resulted in it letting the valve hang about 1mm, so no contact with the piston, very lucky indeed. This was not discovered until I had pulled the motor and taken in to my local shop, where Brett found the problem right away. He put a leak down tester on it and, with the use of some cool looking needle nose pliers, pulled the valve back up so it seated. The leak down tester showed about twice what it should have read, so I just decided that with 220 hours on the motor, to just pull it apart and go through it.
After Brett had pulled it apart he gave me a call to come over and have a look at what he found. Upon arriving at the shop he just looked at me and started laughing and asked me if I had been changing the oil every 5 minutes? He said it looked like he had pulled apart a brand new engine that someone had splashed a little new motor oil on. He said that, with the exception of a couple things everything was perfect, main bearings, trans bearings, big end of the rod, small end rod busing,etc..... Needless to say I was happy about that.
Here's what he did find:
Left side crank main seal was in two pieces.
Cylinder and piston and 4 small scratches below the rings.
Rings were at half wear tolerance, ie end gap measurement.
Intake valves were worn, not too bad but recc. replacement.
Cam chain was worn out. This was the DID that I had just put in, only 40hrs on it. And it was replaced with a new stock unit.
He also found that the crank had a slight amount of run out top to bottom, .004" I believe, and he corrected that as well.
Everything else was in stellar condition. The piston was unbelievable, no scuffing on the skirt, all original machine marks were still visible. Only the small scratches were evidence of any wear.
Brett did a small amount of clean up work on the ports, removing some casting lines and matching the ports to the seats. He also matched the exhaust ports to the headers themselves.
So, now th motor has been re assembled with a new cam chain, rings,(the oil ring by the way is the same as the 950), seals and gaskets, new intakes, new valve springs. All that is left now is to put it back into the bike and break in the new rings.
I had originally intended to take it apart at 150 hours, but, nothing appeared wrong so I just kept riding it. I did have to change the rockers as the exhaust follower had bitten the dust. Then decided to try and go to 250 hours before the tear down, and I almost made it. All in all not bad in my opinion. I'm no hot shoe, but, I do run the motor, pretty hard sometimes when I'm racing, and to have it in this condition when it came apart is just outstanding!!
Brett had a good comment when I told him that I changed the oil after every time I rode it, and that I made sure that the oil never came out black. He said "Oil is cheaper than Metal". I have to agree, as I cannot imagine how much it would have cost if something had failed and torn up a bunch of other stuff.
My hat is off to Cheeseberger for his 10K miles and 349 hours!!
Dale
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