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noisy engine?


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Unfortunately for you, I think I know exactly what it is. A buddy of mine just bought an 02 CRF450 and had the same noise you are describing. (sounds like a bearing going bad somewhere in the bottom end.) The noise on his even came and went. It would occasionally go away completely and make no noise, then come back. He also developed a water leak from the wheep hole of the water pump. The day he found the water leak he broke the counter balancer gear in half. (Luckily it let go at idle and no further damage occured.) He found that the shaft that holds the counter balancer gear was worn and "wobbling" around inside of the bearing on the left side of the engine. (The opposite side of the shaft from where the counterbalancer gear is.) Hope that makes sense. ?

The shaft moved around enough, on the left side of the engine, to wear out the water seal and put enough stess on the counterbalnancer gear to snap it in half, which are both on the right side of the engine. (water seal/impeller shaft prob's are very common for the CRF's) He replaced this shaft and bearings, and the noise went away completely.

PS. he was also getting quite a bit of metal in the tranny oil. Change your tranny oil and if it comes out gray,,, that's another indicator that the shaft may be wearing. (yes the portion of the counterbalancer shaft that is on the left side of the engine, is lubricated by the tranny oil which is on the right side of the engine!)

Good luck. I hope I'm wrong, and it's something a little easier, but it sure sounds like the same thing.

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Well, I hope that's not the case.... so you say the problem came from the bearing on the left side of the engine? How hard is the bearing to get to and is it easy to change? The trans oil does come out a grayish/black color but my experience is that all tranny gear oil seems a little gray before changing. I checked the bearing on the counterbalance on the right side after reading in the forums of someone having a bearing spinning inside the case and it seems fine..... never would have suspected something on the left side though. Oh yeah, the noise he had that would "come and go".... was it a knock sound or something like a bad fan belt?

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my gearbox smashed on my 02 months back. When I cracked her open some of the bearings holding the gearbox shafts looked like they had been walking. There were marks that suggested the outer wall of the bearing was turning.

I wonder if that could have anything to do with the whirring noises that people talk about.

I can tell you this didn't cause my gearbox to screw up, that was something else.

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I had the same exact problem in my '04. Sounded terrible. I had no idea what it was so I ordered everything that moved and tore into it. Once I got the cases split I found that the shaft was worn on the left side and the bearing was trashed. The bearing was a b*tch to get out. I broke it and eventually ended up having to weld across the bearing so I had something to pound on to get it out. Not fun or cheap. If anyone ever does a search of my posts they will see me complaining about the same thing over and over. I have had problems with this counterbalance shaft on my '02, '03, and '04. Mostly on the right side. If the '05 does the same I will be blue in '06. I am tired of spending more time working on bikes than riding them. If I could ride a two smoke anymore I would get one of them.

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Well here is an update on the motor. Got it the rest of the way apart today, and the balancer shaft is worn, but interestingly only on one half..... the side that the weight is on. It's like the weight is putting so much pressure on the bearing on the left side of the case that its sticking to it instead of rotating inside it. The left bearing has a snap ring I guess to keep it in if the bearing starts to spin inside the case but it does do anything beyond that I don't believe. The left side case bearing is a needle bearing not a roller like the right side. The noise must (almost like sand paper in the engine)be coming from the grooves on the one half of the bearing suface of the shaft. After reading one of the replies earlier, it seems as though the other guy's buddy must have had the same noise. I also went by a friends house tonight and had him start his and his did not make the noise I'm hearing. Gonna order the parts soon... looks like aroung $150 for the shaft and 6-10 dollars each for the bearings.I think if Honda would change the type of bearing on the left side and add some sort of bearing or bushing inside the water pump housing where the impeller could ride, we would have a much more stable system. I know this is long but hope it helps someone else! Also search "water pump leaking" and you'll read some more on this problem that seems to start as water leaking from weep hole. Although, some are fixed with just a new seal. Just be sure to check. I'll update again when I get it back together.

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Exactly what happened to mine. Same wear pattern on the shaft. Getting that needle bearing out will be a pain. Once you get it back together it will be good as new. I would also replace the bearing on the other side (right side). It's a $5 part. Make sure the right side bearing OD does not spin in the case. Both were worn on mine. If it does spin in the case you can pean it with a punch so it is a tight fit. Keep us updated on how it goes.

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My 03 developed these symptoms last weekend: Loud "whirring" noise, weeping water pump, and gray slimey transmission oil,and coolant level down from where it always is. From what I see here in this thread, I am in for more than just changing waterpump seals/bearing/shaft....right? ?

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Here's the final update.... it's fixed!!! After aprrox. $230 it's fixed!! Probably didn't need to change everything but I did. Noise is gone and no water leaking. Here's the list of what I replaced: balancer shaft, left side needle bearing,oil seal,right side bearing, water pump shaft, oil seal, water seal, water pump bearing,left and right case gaskets. The water pump bearing "seemed" good as well as the right bearing for the balancer shaft but I changed them as a precaution since they weren't that expensive. The balancer shaft is $147.00!! The rest was $5 here, $5 there.

I did buy a service manual and found something interesting in the process. The book shows the pressurized lube system servicing the left balancer bearing (the needle one)but in reality it is being oiled by the transmission lube which has to come all the way across the engine through the shaft tube!The balancer oil seal on the left keeps engine oil out of the space.With this I have a suspect that if anyone leans their bike on the throttle side up against a wall for storage, and then starts the bike with the choke, that left bearing starts DRY EVERY TIME. Also my bike was being run with regular anti-freeze when I got it which might explain the heavy grooves in the water pump shaft. Some ICE is going back in it! That's it...hope this might help someone else out there. If someone needs part numbers, I wrote them down. Just let me know... might save ya some time on the phone.

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Thanks! Good info. I ordered waterpump parts from service honda. I plan on replacing them...and hoping that will quiet the engine noise. If not, I know where to look the next time I have to go into the crankcase (counterbalancer bearings). By the way, this forum rocks compared to others. I was on a jetski forum asking about mail order parts for watercraft with no replies. But this is helpful stuff! LB

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Take my advice..... you should go in and inspect the balancer shaft. Take it out and look at it. There's no mistaking the wear pattern. Looks like the needle bearings are stuck in one place. Several posts talked about how some guys just replaced the water pump parts and then the bearing seized for the balancer shaft. It's only a matter of 10- 20 bucks for the two gaskets for the 2 covers. Trust me... it's worth it. If you have a winning noise. The needle bearing and shaft are trashed.Plus, it's not really a big job. The hardest part is removing the needle bearing itself. I just used a long 3/8 drive extension with a 1/2 or 9/16 socket and drove it out from the other side. Just be sure to remove the plastic oil pump gear from the left side. The needle bearing hits it on the way out. Good Luck!!

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Damn, after reading this post I am a little nervous. I also get a whirring sounds and I thought it was just the engine noise bouncing off of the skid plate I put on.

If I have to break into my case its might have to wait till after christmas. I already have my sons bike apart after he hydro locked it this past weekend.

How hard is it to replace these parts?

Should I get someone mechanically inclined?

?

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To answer the question about how hard it is to replace the parts for the balancer shaft..... NOT HARD!!! The hardest part is removing the needle bearing on the left side, but even that only took me about 10 min..JUST BE SURE TO REMOVE PLASITC OIL PUMP GEAR! You don't have to split the case. Only the flywheel cover and right side cover have to be removed.Buy a manual and pay close attention to seal direction.

As far as changing the oil, I just bought mine from a friend and when I picked it up the noise was already there. I don't race so I probably won't change mine as often as some but it will be frequent. I'm using Motul oil now.

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Good advice.... I took the shaft out to look: I found the left side worn by the needle bearing,but I cant see anything wrong with the bearing. I also found that the shaft flange that sits against the right-side roller bearing is almost half gone! This right bearing seems too loose, but is not turning in the case. This bearing basically feel out when I first touch it with the punch(line-up tool). I will try to include some pitures of the shaft. im000516.jpg sorry,little out of focus... im000517.jpg

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sorry,miante, check it now

Crazy thought: Lets get rid of the counterbalance weights that contribute to it's self destruction. A friend says they used to take them out on his race bikes. Reved faster, but more stalls, etc. Can we run it with the weights off, but the shaft and gears still run the water pump on the right, and the oil pump on the left. No I dont have a degree in engineering, so tell me how my engine will self destruct.....

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? llbrownwheel, the left side of your counter shaft is just fine. If you buy a new countershaft it will be the same way. My bottom end in my 03 crf went about a month ago, One of the ball bearings in the right side main bearing went, then it started to eat the rest of the bearing. The engine started to make a very loud metal-to- metal noise. I shut the engine down as soon I herd it, its a good thing i did shut the engine off when I did or it might of bin a catastrophic failure. When I took the engine apart I found the oil pump was damaged from all the metal particals from the main bearing. Then the oil pump scratched the hell out of both cases, (REQUIRING NEW ENGINE CASES) Here's a list of all the parts I had to replace.

Both left and right engine cases, crank shaft, crank shaft main bearings right and left, oil pump, oil pump shaft, every transmisson bearing, counter shaft bearings right and left, oil reed valve, every seal in the motor, I'm not sure but I think that everything ? My counter shaft did have a very small amount of wear on the needle side of the shaft, the wear was in the same spot as the counter shaft weight, it was nothing that I could feel with my fingers and it was still in spec so I just replaced the two shaft bearings. I will be using Synthetic motocycle oil in my tranmisson from now on, I hope it will stop the counter shaft from wearing any further. I could have reused my transmisson bearings they were in mint condition but they were so cheap I replaced then anyways. I finaly have my engine in my bike and its running like new. Its amazing how quiet my engine is now, it seems like it makes less noise now then when it was new. I also used synthetic oil in my engine and transmisson when I broke the motor in. My top end was in mint condition so I reused all the top end parts.

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Water pump fixed. Service Honda is the bomb! They claim delivery in 7-10 business days; parts got to me in 4 days! And saved lots $ over dealer prices. AND they said they will also be able to provide me with PWC parts whereas my dealer said they could not. The notorious leaking CRF 450 water pump: http://www.servicehonda.com/hard%20parts/off%20road/crf450r%2002-04/water%20pump.htm

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