Repairing damaged cams: FC 350 running without oil..

addimatty
Edited Date/Time 10/5/2020 10:22pm
Hey! So I had unfortunate situation yesterday as I went for a race, did qualification, all good. Before going to 1st moto checked the oil level (as I changed it in the previous evening before race day), the level was perfect. But then after 6 minutes in moto 1 the engine became quite loud and I could not figure out the problem, did ride for 3-4 more minutes max, finally stopped and noticed that apparently I did screw in the oil drain bolt by hand and forgot to tighten it (I was helping simultaneously my brother to help fix his bike + we had some friends over at the garage and lost focus on my bike as I had to help him and stop doing my stuff) - > so in the end the bolt was missing and there was no oil at all left Sad Sad Sad Sad I dropped of the bike to my mechanic but has anyone had any experience with this? The engine did not seize up, but I assume Im looking at new main bearings, rod, piston, cylinder, clutch? and in the best scenario hope that the transmission isn't fooked up? I hope the camshafts should not be fooked up either? Feeling so stupid, guilty and angry about myself, wanna hit myself a couple of times Sad

P.S. bike only has 30 hours Dry
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SwapperMX
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SwapperMX 9/27/2020 5:33am
9/27/2020 5:33am
A friend of mine did a similar thing. But he finished the moto before pulling in. Motor was still running at the end of the moto. When we got the motor apart the thing was toast. Every gear in the gearbox was blue from the heat. Needed a full rebuild from top to bottom. Hopefully yours isn't that bad but it's likely not going to be good.
addimatty 9/27/2020 6:38am
9/27/2020 6:38am
SwapperMX wrote:
A friend of mine did a similar thing. But he finished the moto before pulling in. Motor was still running at the end of the moto...
A friend of mine did a similar thing. But he finished the moto before pulling in. Motor was still running at the end of the moto. When we got the motor apart the thing was toast. Every gear in the gearbox was blue from the heat. Needed a full rebuild from top to bottom. Hopefully yours isn't that bad but it's likely not going to be good.
Thanks for reply! Ooh man, sounds expensive Sad yeah I did not finish the moto completely and I did not rev it too hard all the time as Im novice, but will see Sad
Sachmo831
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Sachmo831 9/27/2020 3:04pm
9/27/2020 3:04pm
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
kb228
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kb228 9/27/2020 4:47pm
9/27/2020 4:47pm
Id assume the head is trashed
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addimatty 9/27/2020 8:31pm
9/27/2020 8:31pm
Sachmo831 wrote:
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil [img]https://p.vitalmx.com/photos/forums/2020/09/27/451561/s1200_20190128_124342.jpg[/img]
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
Yup, sems like its going to be crazy expensive repair. Any chance to repair the head or new one?
Sachmo831
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Sachmo831 9/27/2020 11:07pm
9/27/2020 11:07pm
Sachmo831 wrote:
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil [img]https://p.vitalmx.com/photos/forums/2020/09/27/451561/s1200_20190128_124342.jpg[/img]
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
addimatty wrote:
Yup, sems like its going to be crazy expensive repair. Any chance to repair the head or new one?
Depending on the severity of the damage the head can be repaired. There are several shops across the country that can do it. I sent the 250f head to advanced machining services and it cam back good as new. Good luck on the tear down
1
addimatty 9/28/2020 1:07am
9/28/2020 1:07am
Sachmo831 wrote:
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil [img]https://p.vitalmx.com/photos/forums/2020/09/27/451561/s1200_20190128_124342.jpg[/img]
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
addimatty wrote:
Yup, sems like its going to be crazy expensive repair. Any chance to repair the head or new one?
Sachmo831 wrote:
Depending on the severity of the damage the head can be repaired. There are several shops across the country that can do it. I sent the...
Depending on the severity of the damage the head can be repaired. There are several shops across the country that can do it. I sent the 250f head to advanced machining services and it cam back good as new. Good luck on the tear down
Thanks, appreciate Your input!
yz133rider
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yz133rider 9/28/2020 5:23am
9/28/2020 5:23am
addimatty wrote:
Yup, sems like its going to be crazy expensive repair. Any chance to repair the head or new one?
Sachmo831 wrote:
Depending on the severity of the damage the head can be repaired. There are several shops across the country that can do it. I sent the...
Depending on the severity of the damage the head can be repaired. There are several shops across the country that can do it. I sent the 250f head to advanced machining services and it cam back good as new. Good luck on the tear down
addimatty wrote:
Thanks, appreciate Your input!
It happened once to my yz250f. Noticed the bike sounded louder and pulled off. Took it back to the pits and noticed Oil soaked mud, and saw the plug missing.

Flushed oil tank and lines with clean oil, fired it up with fresh oil, and never had an issue.

I got lucky and caught it very early on I’m guessing.
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addimatty 9/29/2020 12:05am
9/29/2020 12:05am
Sachmo831 wrote:
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil [img]https://p.vitalmx.com/photos/forums/2020/09/27/451561/s1200_20190128_124342.jpg[/img]
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
addimatty wrote:
Yup, sems like its going to be crazy expensive repair. Any chance to repair the head or new one?
Sachmo831 wrote:
Depending on the severity of the damage the head can be repaired. There are several shops across the country that can do it. I sent the...
Depending on the severity of the damage the head can be repaired. There are several shops across the country that can do it. I sent the 250f head to advanced machining services and it cam back good as new. Good luck on the tear down
btw, could You give me their contactinformation, website or smth?
Moto520
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Moto520 9/29/2020 9:12am
9/29/2020 9:12am
my opinion is that there is enough oil in the cavities to help enough with lubrication for a short period. I did the same thing and needed a full rebuild because i ran the bike until it stopped. FWIW....i rode it in sand for 2 hours without oil before she stopped. This was on a 2013 CRF250R....this bike has separate compartments for engine oil and transmission oil. I had no oil in the engine oil side.
2
JK714
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JK714 9/29/2020 10:19am
9/29/2020 10:19am
Good luck with the bike. I had a somewhat less severe episode recently with my 2008 CRF450R, which has a lot of aftermarket $ in it with low hours (Factory Connection revalve, Rekluse Core EXP).

I have boatloads of o-rings laying around and some are just perfect for the oil filter cap, but some are just a little too big. I accidentally used one of the bigger ones and didn't realize the mistake until getting back from a 15 minute practice moto.The bike ran perfect the whole time, never smoked or made noises, etc., but I noticed an oil drip from the cap and nothing in the sight glass. Borrowed some oil to fill it up and when I did a layer of black grunge floated to the top. I estimate I lost at least half the oil on the motor side (trans is separate).

Quit for the night right there and drained/flushed both sides copiously with oil before refilling. Have not run it since (have 2 other bikes). Fingers crossed.
Tuna
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Tuna 9/29/2020 10:58am
9/29/2020 10:58am
Sachmo831 wrote:
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil [img]https://p.vitalmx.com/photos/forums/2020/09/27/451561/s1200_20190128_124342.jpg[/img]
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
I roached my top end/head on a 350 from a blocked oil squirter. Those 350’s like a lot of oil flow. I had my cam journals repaired. Needed new top end/cylinder and cams, seals etc.
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addimatty 9/29/2020 10:38pm
9/29/2020 10:38pm
Sachmo831 wrote:
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil [img]https://p.vitalmx.com/photos/forums/2020/09/27/451561/s1200_20190128_124342.jpg[/img]
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
Tuna wrote:
I roached my top end/head on a 350 from a blocked oil squirter. Those 350’s like a lot of oil flow. I had my cam journals...
I roached my top end/head on a 350 from a blocked oil squirter. Those 350’s like a lot of oil flow. I had my cam journals repaired. Needed new top end/cylinder and cams, seals etc.
Where did You repair cam journals? This issue is somewhat common as I heard about this from others as well. The difference is at least You had oil in bottom end for crank/transmission, but I did not haha. I have decided to disassemble the entire engine just to be sure.
addimatty 9/29/2020 10:39pm
9/29/2020 10:39pm
JK714 wrote:
Good luck with the bike. I had a somewhat less severe episode recently with my 2008 CRF450R, which has a lot of aftermarket $ in it...
Good luck with the bike. I had a somewhat less severe episode recently with my 2008 CRF450R, which has a lot of aftermarket $ in it with low hours (Factory Connection revalve, Rekluse Core EXP).

I have boatloads of o-rings laying around and some are just perfect for the oil filter cap, but some are just a little too big. I accidentally used one of the bigger ones and didn't realize the mistake until getting back from a 15 minute practice moto.The bike ran perfect the whole time, never smoked or made noises, etc., but I noticed an oil drip from the cap and nothing in the sight glass. Borrowed some oil to fill it up and when I did a layer of black grunge floated to the top. I estimate I lost at least half the oil on the motor side (trans is separate).

Quit for the night right there and drained/flushed both sides copiously with oil before refilling. Have not run it since (have 2 other bikes). Fingers crossed.
Dooh, crazy. Hopefully your bike will be fine!
Tuna
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Tuna 9/30/2020 2:52am
9/30/2020 2:52am
Sachmo831 wrote:
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil [img]https://p.vitalmx.com/photos/forums/2020/09/27/451561/s1200_20190128_124342.jpg[/img]
The cam journals don't last long without oil flow. This is from a yz250f that was ran out of oil
Tuna wrote:
I roached my top end/head on a 350 from a blocked oil squirter. Those 350’s like a lot of oil flow. I had my cam journals...
I roached my top end/head on a 350 from a blocked oil squirter. Those 350’s like a lot of oil flow. I had my cam journals repaired. Needed new top end/cylinder and cams, seals etc.
addimatty wrote:
Where did You repair cam journals? This issue is somewhat common as I heard about this from others as well. The difference is at least You...
Where did You repair cam journals? This issue is somewhat common as I heard about this from others as well. The difference is at least You had oil in bottom end for crank/transmission, but I did not haha. I have decided to disassemble the entire engine just to be sure.
CV Tech. They are the big guys in Canada that replate cylinders and rebuild cranks.
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addimatty 9/30/2020 2:13pm
9/30/2020 2:13pm
Tuna wrote:
I roached my top end/head on a 350 from a blocked oil squirter. Those 350’s like a lot of oil flow. I had my cam journals...
I roached my top end/head on a 350 from a blocked oil squirter. Those 350’s like a lot of oil flow. I had my cam journals repaired. Needed new top end/cylinder and cams, seals etc.
addimatty wrote:
Where did You repair cam journals? This issue is somewhat common as I heard about this from others as well. The difference is at least You...
Where did You repair cam journals? This issue is somewhat common as I heard about this from others as well. The difference is at least You had oil in bottom end for crank/transmission, but I did not haha. I have decided to disassemble the entire engine just to be sure.
Tuna wrote:
CV Tech. They are the big guys in Canada that replate cylinders and rebuild cranks.
Thanks for information!
1
addimatty 10/3/2020 11:20am
10/3/2020 11:20am
Hey guys! So I finally had a look into engine .. Im a bit surprised as bottom end does not need rebuild, at least judging by that it spins freely, there is no feel that smth is damaged + there are still signs of oil on crank, rod, cases after running 4 minutes dry.. seems like I will stick with silkolene pro4 10w50 oil .. also rod is in perfect condition, no sign of wear for the pin of piston, neither on the rod. However, the cylinder head definitely needs a repair/new head. So guys, what do You think regarding cylinder - would you leave it as is or try to hone it a bit? And regarding cams - currently Im thinking about polishing them up with some ultra fine scotch brites and leave them as is. The idea is to i) change/repair cylinder head, ii) new piston, iii) polish cams. What do you think guys?












FGR01
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FGR01 10/3/2020 2:49pm
10/3/2020 2:49pm
I don't think those cams are worth trying to salvage.
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DB97
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DB97 10/4/2020 9:22am
10/4/2020 9:22am
I made a mistake and broke the oil pump gear causing similar damage on my kx. I replaced main bearings, crank, cylinder, piston, head, cams. I’d rather be over cautious then risk another failure that could happen at any time. Although I did get my old head repaired and he only polished the journals for a few minutes. It’s just on the shelf, I’m still hesitant to use it.
Tuna
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Tuna 10/4/2020 12:45pm
10/4/2020 12:45pm
Those cams are roached. Buy new ones.
omalley
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omalley 10/4/2020 1:15pm
10/4/2020 1:15pm
Tuna wrote:
Those cams are roached. Buy new ones.
Agreed...plus the followers look blued from heat as well.
DynoDan22
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DynoDan22 10/4/2020 7:26pm
10/4/2020 7:26pm
In all honesty, the motor should be split and every component inspected and measured. The oil pump rotors need to be inspected and the complete lubricating system need to be cleared of any debris. Starving the oil pump can cause some major issues. You will throw new parts at it but if the lubrication system has been damaged from lack of oil, you'll ruin all of the new parts. A triple "O" scenario (out of oil) requires a full tear down and inspection.
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addimatty 10/5/2020 1:25pm
10/5/2020 1:25pm
Hey guys. So I went to dealer today, spoke with the mechanic and he confirmed that new head is a must. Showed him cams, he told that its no big deal and I can try to clean them up home. So I did, bought scotch brite very fine (360grit) and ultra fine (1500grit), and cleaned them up. Took like 10-20 spins for the round spots and for cam lobes just like 3 times around with scotch and You can see result in the pics. Obviously, they are not perfect, but they feel extra smooth, without any sign of scoring on the polished spots, and I assume I have taken of smth like 0.001 mm if even any. I have decided not to split bottom end, as oil filter was without any particles, neither the mesh filter, also clutch was still soaking in the oil and no particles, no wear/signs of burning at all. Next step is to flush bottom end several times, disassemble and check the lubricating system, clean the oil squirters in the head, assemble head with valves, cams. Then new piston, gaskets and hopefully ready to ride again without any surprises.



Leeham
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Leeham 10/5/2020 3:41pm
10/5/2020 3:41pm
Hopefully no issues with the transmission shifting or hitting false nuetrals
addimatty 10/5/2020 10:22pm
10/5/2020 10:22pm
Leeham wrote:
Hopefully no issues with the transmission shifting or hitting false nuetrals
I think it should be fine, as the clutch was still soaking in oil and there were some oil still on crank, cases, rod so also transmission most likely had some residual oil still there.

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