Well they only get tighter with burning, not back into spec.
Interesting about the plug. It was replaced because it fouled at 12k miles. Husband was not tacking high enough. He wouldn't listen to me so the tech explained to him. I wonder if the past riding activity caused it? Tech is stumped. He says everything looks perfect inside (including the newly replaced spark plug) except the burnt valves. I'm not a techie and he explained it to me fully and I understand what he said but couldn't repeat it properly if I tried. It is covered under an extended contract. The inspector will be out to see for himself before covering the job. So far my tech has talked to three different honda techs, my father one and I talked to the service dept on another island and none of them have an explanation. Nobody has heard of it. The other dealership here that has two of them in the shop for the same reason.....is because the bikes had oil pressure problems and never had one service. Engines look destroyed inside. Mine looks perfect...except the heads. I'm thinking we will never know why it happened.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.
That doesn't make sense to me either. A fouled plug? It takes a lot to foul a plug on a F.I. bike with electronic ignition. Just lugging around won't do it.Interesting about the plug. It was replaced because it fouled at 12k miles. Husband was not tacking high enough. He wouldn't listen to me so the tech explained to him. I wonder if the past riding activity caused it? Tech is stumped. (SNIP)
Is the MOM the normal user manual? Because mine doesn't have any values for that. I just keep the RPM in a range where the engine doesn't "complain" by growling deeply and not running smoothly.I try to keep it above 5k. It does get a bit loud but that's fine by me!
The MOM has values for when to shift / mph
American owners manual page 27Is the MOM the normal user manual? Because mine doesn't have any values for that. I just keep the RPM in a range where the engine doesn't "complain" by growling deeply and not running smoothly.
I confused, I believe lugging is putting heavy load to engine with incorrect gearing ratio. In short, too early shifting up. Correct me if I am wrong. My Thailand manual page 27 is about Brakes. I read the English version manual as I am Malaysian. Non is telling about Shifting rpm for 2013 manual. But if 1-2nd gear not more than 20kmh, I am in trouble..mine usually 30-40kmh 2nd gear shifting depend on hot and cold engine. If final gear not more than 60kmh shifting to 6th, more trouble to me. At least I will cruise 70kmh in 5th for 10 minutes or more to heat up early morning commuter. I took a good 180 degree corner at 80kmh in 5th before entering highway. Depend on traffics, but normally as soon as out of the corner at rpm 6k approximately 85kmh, it smoothly asking for 6th effortless (almost no clutch involve)..and if I am in the mood to catch the fast lane earlier, 5th gear always winner..up to 9k rpm easy and 10k with anger..I consider my self over raved but is that means lugging too? Mine 2013 now clocking 33000km never had problem except for rear sprocket bearing damage at 30000km+-. Never change sprak plug, using fully synthetic oil every 3k, commuting 1 hour 140-150kmh most of the time on highway. Advice me if these will cause an issue for my next 1600km journey kuala lumput to puket island. .I will be the smallest among others in convoy. I have seen kawasaki er6n getting problem with exhaust valves for its metal fatigue. .I am worried if honda does the same?Thanks. Then I'm not lugging the engine and can actually even shift earlier into 6th gear.
Funny that the US version comes with a different manual. The English version of my 2011 manual tells me something about the steering lock on page 27...
I agree - it still doesn't make sense.So let me get this straight, burnt valves due to low rpms. Because low rpms generate sooooo much heat. Not sure I buy the explanation of carbon build-up due to low rpms. Sounds like hand waving blaming the rider instead of Honda for a touchy design.
This is what I was going to point out -- the new D.I. Honda Fit w/CVT runs at very low rpms compared to the M/T model! Hmm, but the CBR250R isn't direct inject, only port injected.Look at the RPMs that cars are running consistently - 2000 or less - without issues CBRs are cruising at low RPMs all the time, and I've not heard of any valve issues.