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I have just been informed that my 2012 cbr has burnt valves. He states the valve clearances were normal but compression test revealed a valve issue. He took it apart today and said that the valves were burnt and they need to go to the machine shop and another 8 hours of labor! When I asked what could cause this he said since the clearances were good the only thing he could think of is bad gas! I've put 15k miles on it in two years. It is a commute vehicle and gets a new tank every week! Have I been transported to another planet or is this a common thing with this bike?
 

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Discussion Starter #5
Update

After full inspection, it was noted that the valve clearance was right on but they still got burnt. There is currently no explanation as to why they got burnt. Tech is stumped. Tech was told by another honda dealership that they had two bikes in their shop with same problem. I smell a recall.
 

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All sensors checked out. That is with new valves/parts. He said machine shop is only if he takes the valves out and the part they sit on need machining. He wouldn't know if that is needed until he gets into it further. I'm not understanding the extra labor either. A valve job covers dismantling and putting it back together. Shouldn't it just be an extra charge for the parts? What am I missing?
 

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New tank every week. Honda techs are saying it is a design flaw. That oil isn't getting to the top of the engine. If that's the case, why aren't we hearing more about it? Nobody here is having this problem. I do find it interesting that when I got it serviced at Honda, they always put too much oil in it. Once I got it serviced outside of honda the oil was filled perfectly to the line and a thousand miles later...burnt valves.
 

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New tank every week. Honda techs are saying it is a design flaw. That oil isn't getting to the top of the engine. If that's the case, why aren't we hearing more about it? Nobody here is having this problem. I do find it interesting that when I got it serviced at Honda, they always put too much oil in it. Once I got it serviced outside of honda the oil was filled perfectly to the line and a thousand miles later...burnt valves.
You need them to show you exactly what they mean when they say "burnt valves". If there isn't oil to the top of the engine the roller rockers and cam lobes should be damaged and blue from the friction. Typically if an engine has a burnt valve it's from hanging open too long (incorrect adjustment), a very lean mixture, incorrect ignition timing, or detonation. What does the plug look like? That will tell you something about what caused the problem.

I would want to see the valves (and plug) and hear a good (better) explanation from the tech of what he believes caused the problem. I would also contact Honda technical service and hear what they have to say. I don't see the explanation of "bad gas" as a real possibility unless the octane was too low and you were detonating consistently. It's possible, but you would have to be under heavy load at low RPMs to do that. If that was the case the plug should be a melted mess.
 

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You need them to show you exactly what they mean when they say "burnt valves". If there isn't oil to the top of the engine the roller rockers and cam lobes should be damaged and blue from the friction. Typically if an engine has a burnt valve it's from hanging open too long (incorrect adjustment), a very lean mixture, incorrect ignition timing, or detonation. What does the plug look like? That will tell you something about what caused the problem.

I would want to see the valves (and plug) and hear a good (better) explanation from the tech of what he believes caused the problem. I would also contact Honda technical service and hear what they have to say. I don't see the explanation of "bad gas" as a real possibility unless the octane was too low and you were detonating consistently. It's possible, but you would have to be under heavy load at low RPMs to do that. If that was the case the plug should be a melted mess.
+123
Plugs usually tell a lot about the engine.
Oil another.

If both of those looked fine and the mechanic is saying its burnt valves.........

As far as bad gas.
It is possible our little engines really do need ethanol free gas. I could imagine even 10%blend hurting our engines in 10k if thats all thats been put in.
Who knows.
 

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Ethanol

+123
Plugs usually tell a lot about the engine.
Oil another.

If both of those looked fine and the mechanic is saying its burnt valves.........

As far as bad gas.
It is possible our little engines really do need ethanol free gas. I could imagine even 10%blend hurting our engines in 10k if thats all thats been put in.
Who knows.
My bike has over 30k on ethanol blend. I would hate to see what it looks like inside :) .. It has lost a bit of power recently. I haven't had the time to look into it. I did test compression and it's still good. These bikes just keep on ticking. Especially the valves.
 

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Remember the engine stall thread, too lean during decel + clutch pull. So how often are these engines running overly lean actually.
 

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Remember the engine stall thread, too lean during decel + clutch pull. So how often are these engines running overly lean actually.
I know I get some nice pops from my akra exhaust+dfc on shift and sometimes on decel.

Not the normal gurgle pops, but the pressure pops :eek:

It's a Honda. I'm a believer the motor even if it has problems, will keep on running.
 

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It's a Honda. I'm a believer the motor even if it has problems, will keep on running.
Curiously, the 1st gen Honda Fits are turning out to have some serious problems before 100K miles that aren't typical (water leaks from cracked roof welds, alternator failures, and valves) ... Honda doesn't always hit home runs. I let my Fit go due to the valve issue. This is the same (half) engine base used in the NC700X motorcycle! Which is why the NC700X has a crazy low redline of 6500 like the Fit. Anyway.
 

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Curiously, the 1st gen Honda Fits are turning out to have some serious problems before 100K miles that aren't typical (water leaks from cracked roof welds, alternator failures, and valves) ... Honda doesn't always hit home runs. I let my Fit go due to the valve issue. This is the same (half) engine base used in the NC700X motorcycle! Which is why the NC700X has a crazy low redline of 6500 like the Fit. Anyway.
I have a 2010 Honda Fit, 108,000 original miles. Only have done oil changes, trans fluid, tires, filter, plugs.

Still running fine. :)



The salesmen did say "The extended warrenty wont cover the dash if it starts to peel" I asked him if he had seen any and he said the previous models did have the dash coming apart.

My fit is very practical and I love it.


No I haven't always been an import or Honda guy.
Owned Fords and a Jeep primarily. :p
 

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After full inspection, it was noted that the valve clearance was right on but they still got burnt. There is currently no explanation as to why they got burnt. Tech is stumped. Tech was told by another honda dealership that they had two bikes in their shop with same problem. I smell a recall.
I'm questioning whether one can measure the clearance on burnt valves, after the damage was done, and then state that they are within spec... I'd wager that they were too tight prior to burning.

What is the service history of the bike?... Was the valve clearance checked early on, within the first 1500 miles since new?
 
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