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Why so many horror stories about CRF's?

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I probably know the answer to my own question, the answer being that the horror stories come from owners that don't change their oil or clean there air filters, plus there is the Honda bashers, but I was just wondering how many of you have gotten many hours out of your original top ends?

I have had my '05 for a year and a half now, and on average ride MX every other weekend if not a little more, and my valves have stayed in spec since it was new. I do change my oil every other ride, and stay off the rev limiter too, as I'm sure that goes a long way with these machines.

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Trail riders tend to overheat their engines and that's the #1 factor in valve life. Clean air is important but you don't have to clean the filter every ride. In fact, I wait to service my filter until it's really dirty on the outside. If you properly saturate the filter with oil, you will never pass dirt through the filter, no matter how dirty it gets on the outside. The guys that service their filters every ride, drop more dirt in their air boot than the filter will ever pass. Bouncing off the rev limiter from time to time won't hurt the valves either. Only sustained high rpm like a supermoto racer will wear the valves out prematurely.

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Trail riders tend to overheat their engines and that's the #1 factor in valve life. Clean air is important but you don't have to clean the filter every ride. In fact, I wait to service my filter until it's really dirty on the outside. If you properly saturate the filter with oil, you will never pass dirt through the filter, no matter how dirty it gets on the outside. The guys that service their filters every ride, drop more dirt in their air boot than the filter will ever pass. Bouncing off the rev limiter from time to time won't hurt the valves either. Only sustained high rpm like a supermoto racer will wear the valves out prematurely.

That's actually exactly how I treat my air filter. In the winter when I just ride indoor I never clean it. In the summer on real dusty days I might clean it every ride then, if the filter is covered in dust.

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So far I have 96 hours on my 06, beat the hell out of it, Im a 205lbs rider, tha ri/races mainly MX and hits the dunes a couple times a year. No issues with anything, top end is still strong as hell, and I ride normally 2x a week. Ever sice I re-shimmed from the initial 10hr break-in period, They havent budged! Oil changed every 5 hours, oil flter every 10, air cleaner as needed...I would suspect that I still have quite afew more hours on it before having to do the top end...

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In our racing group of multiple CRF450s, dating back to the first year and through '07, there have been zero failures, horror stories or even any gotta-do-it repairs. Valves have generally stayed in sync or needed only one adjustment.

You're talking about a group of Vet riders who race most weekends from April though October, mostly mx but the occassional hare scrambles plus all-day practice sessions. Lotsa hours on all the bikes.

The CRFs have been stone reliable, and ditto the CRF250Rs in the group.

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50 hours on my 2005, valves died.

never adjusted the 2003, 200+ hours.

It is a crapshoot. According to Ron Hamp (RHC), it is the relationship between the valve coating and the seat. Sometimes the valve gets a bunch of coating, sometimes it does not. Also, the seat hardness is also the key. In fact, on the 06-07 CRF's, the seat is made softer so it is easier on the valves (at least according to Honda).

And, anyone who says it is dirt intake is nuts. If the dirt was coming into the motor, it would affect the piston and other engine parts. My 05 valves died at 50 hours and the cylinder and piston spec'd out exactly right.

James

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Here is my take:

Owning a Honda is the equivalent of being a Laker fan or a Yankee fan. If you are not a Laker fan, you HATE them and same goes for the Yanks. Why do people hate these teams? They are the best franchises in their sport and have great legacies. They have left a lot of losers in their wake. I take this same argument and apply it to Dirtbikes, just substitute Honda for the L.A. Lakers or NY Yankees.:applause:

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Here is my take:

Owning a Honda is the equivalent of being a Laker fan or a Yankee fan. If you are not a Laker fan, you HATE them and same goes for the Yanks. Why do people hate these teams? They are the best franchises in their sport and have great legacies. They have left a lot of losers in their wake. I take this same argument and apply it to Dirtbikes, just substitute Honda for the L.A. Lakers or NY Yankees.:ride:

I know this is probably a pointless post, but lately the NY Yankees have been sucking some big ones. (btw i am a yankee fan). Almost the same thing with Honda and their racing. Ive been watching supercross and Honda just isnt at the top anymore. So far from what i have seen Kawi is dominating. I know this doesnt exactly link to the quality of Honda's bikes because for four strokes honda is tops (and the race bikes have 150k into them). I really dont know where im going with this, so ill stop typing now. :lol:

:applause::lol: :lol: :eek::naughty::lol::worthy:

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I know this is probably a pointless post, but lately the NY Yankees have been sucking some big ones. (btw i am a yankee fan). Almost the same thing with Honda and their racing. Ive been watching supercross and Honda just isnt at the top anymore. So far from what i have seen Kawi is dominating. I know this doesnt exactly link to the quality of Honda's bikes because for four strokes honda is tops (and the race bikes have 150k into them). I really dont know where im going with this, so ill stop typing now. :ride:

:applause::lol: :lol: :eek::naughty::lol::worthy:

That was funny. You are right, the Yanks have not won a title in a few years, however they are still THE franchise associated with baseball. You know, the whole "evil empire" thing. I am actually a Dodger fan and hate the Yankees for the very reason I stated above. As for the bikes. Put Bubba Stewart on a Schwinn and he will still be the points leader.

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It is a crapshoot.

I think that pretty well sums it up. "Quality Control" from the factory. Most brands and factories don't produce all their parts in house. The parts are sub-contracted out so a set of valves and cylinder head on one bike is from contractor A and the next bike or even the fifth bike down the same assembly line has a set of valves and head from contractor B.

I've been following this valve issue thing for the last year. It seems to me that it can't be narrowed down to just any one thing being the cause. I bought my 04 model used in 06. The first owner worked at the dealership and it stayed maintained by a Honda mechanic each week.

My cylinder head is at the shop right now getting the seats re-cut. The valves, springs, guides and the seats were all worn out. Other bikes built in the same year as mine are still going strong. My thoughts are who was the original sub-contractor to produce those parts. Hmmm???

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MOST things in life are a crap shoot, so bikes are no different. Your job, your wife, your girlfriend, your parents, the weather, the commute to work . . .

A bike built on Monday after the first coffee break, or the last one built on Friday when they all want to get outta there and go drink sake.

Luck of the draw. Sometimes you win, sometimes you lose.

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I know this is probably a pointless post, but lately the NY Yankees have been sucking some big ones. (btw i am a yankee fan). Almost the same thing with Honda and their racing. Ive been watching supercross and Honda just isnt at the top anymore. So far from what i have seen Kawi is dominating. I know this doesnt exactly link to the quality of Honda's bikes because for four strokes honda is tops (and the race bikes have 150k into them). I really dont know where im going with this, so ill stop typing now. :ride:

:applause::lol: :lol: :eek::naughty::lol::worthy:

The SX argument doesn't really mean anything, because any of the brands would dominate if they hired the fastest riders.

I think Utemachine is meaning that the reputation and popularity for Honda isn't just on the track.

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Been a Honda fan for many years, on my 3rd CRF450, with a CR250 still in the stable for enduro racing. My firts 2 CRF450's I did moto and quite a bit of tight enduro (read over heating) and both needed intakes at the 100 hr mark, along with a few other issues. I bought an older CR250 for tight woods races as I too believe that overheating is a big factor in the intake valve issues. My 06 works fine but few hours on it so far.

Tin

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I think that everyone will agree that the left intake typically zero's out first. If that is true, it is unlikely that dirt entering the engine will only effect the left intake. Same argument for hitting the rev limiter. Some have argued that the coolant jackets are not positioned close enough to the left intake and the extra heat build-up causes the left side failure. That sounds logical, so I think heat is probably a source of the problem. Another source could be quality control, but does the factory employee only install bad valves on the left side ? Something to think about. :applause:

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Ok, so I ride some MX and some trail riding. What do I need to keep my bike cool and save my valves while trail riding?

maybe I should've bout an "x"....nah.

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Ok, so I ride some MX and some trail riding. What do I need to keep my bike cool and save my valves while trail riding?

maybe I should've bout an "x"....nah.

Bailey, a couple of affordable things you can do is the turkey baster coolant over flow, I think the thread is on the other page or two. I just did it to mine and it works phenomenal. Also, I would run engine ice.

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Thanks guys. I've heard of the turkey baster idea but didn't realize 450's had potential overheating problems. Mine has not overheated yet.

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Thanks guys. I've heard of the turkey baster idea but didn't realize 450's had potential overheating problems. Mine has not overheated yet.

Any bike can/will overheat. 2-S or 4-S. You gotta keep 'em moving or moving faster.

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