Richard-BKK Posted January 13, 2016 Share Posted January 13, 2016 Not so long ago on this forum the discussion was about the Benelli TNT300S having a service date on the Cam Chain.... Which is replaceable in less than 15 minutes… We got a complain from a family in Chiang Mai that told us about the son who bought a brand new 2015 Honda CBR300R and the motorcycle developed unexplained sounds from the top-end) for the engine (for the non-mechanics the cylinder head). Until now, the Honda dealer in Chaing Mai have brushed the problem under the carpet and never acknowledge the motorcycle had a problem. The owner visit the Honda appointed and approved Serves Center 4 times and never any mechanic found a problem…. This while the top-end of the engine made a real mechanical metallic sound? We even have prove that one of the mechanics of Honda Chaing Mai wrote about the strange mechanical sound in a report… but apparently it was never fixed… Link to comment Share on other sites More sharing options...
Richard-BKK Posted January 13, 2016 Author Share Posted January 13, 2016 By a quick research by one of the members of the TMEA (Thai Manufacturing Enterprise Association) means that 1 in 100 of the Honda CBR300R and the CBR250R, CRF250F and CRF250M will develop this problem. Link to comment Share on other sites More sharing options...
canthai55 Posted January 13, 2016 Share Posted January 13, 2016 Thanks for the heads-up. CRF250M is in the cards for my next bike. Can a higher quality cam chain be found, USA or UK maybe, and replace the stock one which is of a more poor quality? or is it a design flaw ? Or the tensioner maybe of poor quality ? Thanks Link to comment Share on other sites More sharing options...
papa al Posted January 14, 2016 Share Posted January 14, 2016 By a quick research by one of the members of the TMEA (Thai Manufacturing Enterprise Association) means that 1 in 100 of the Honda CBR300R and the CBR250R, CRF250F and CRF250M will develop this problem. What is the problem exactly, R.? Link to comment Share on other sites More sharing options...
Richard-BKK Posted January 14, 2016 Author Share Posted January 14, 2016 The problem is not the quality of the parts, the biggest problem is that mechanics fail to identify some problems which lead to bigger problems. One of the sources is the vague wording in the Honda CBR300R service manual, which talks about “excessive noise”… But no Honda mechanic seems to give a good explanation what “excessive noise” is… Link to comment Share on other sites More sharing options...
Nebula Posted January 14, 2016 Share Posted January 14, 2016 (edited) No Honda mechanic could do or nobody cared at just one dealer? How many dealers did he try? I have witnessed how unhappy customer who thought he s right kept bugging the dealer about his problem and blaming the mechanincs. The shop did care and after he wasnt satisfied they brought mechanics from the factory in samut prakan who confirmed the same as the dealers mechanics.the customers was riding the wrong way and this was causing the problem/or something like this. Point is dealers especially bigger ones who care about their reputation wont leave and brush a problem under the carpet. Edited January 14, 2016 by Nebula Link to comment Share on other sites More sharing options...
canthai55 Posted January 14, 2016 Share Posted January 14, 2016 What were the exact nature of the Problems ? Chain Slack causing noise? Faulty tensioner same? I am not too concerned, if I do buy one, and the noise happens, and Honda won't/can't fix it, I will bring it home and repair myself. But good to know the most common areas experiencing this issue. Link to comment Share on other sites More sharing options...
ktm jeff Posted January 14, 2016 Share Posted January 14, 2016 There are a number of design flaws , and possibly quality issues , with these 250 / 300 engines in the CRF / CRM / CB / and CBR , that seems to be around the cam chain / cam chain tensioner / camshaft / valves / valve shims area. Cam chain replacement on the well designed Benelli engine is quick and easy , but how long it would take on a Honda , i dont know. I have suggested one of the flaws with this Honda engine lies with the automatic cam chain tensioner - which doesnt work correctly. A replacement with a manual chain tensioner could help , but voids the warranty. The valve clearances also need to be done correctly , which is something some Honda service centres struggle to do right , or at all. Honda has struggled to get this engine right from day one , and examples like this extinguish the light at the end of the tunnel. A once very bright light. Come on Honda , get back to building your once great bikes , before its too late. You no longer have the market eating out of your hand , or the monopoly.. Link to comment Share on other sites More sharing options...
canthai55 Posted January 14, 2016 Share Posted January 14, 2016 Thanks for that. Sent an email to Crf's only to see if this is a problem in USA, and if so what have they found for a solution. Would change the whole setup tho' - sprocket, chain, tensioner, air in the tires !!! Link to comment Share on other sites More sharing options...
canthai55 Posted January 15, 2016 Share Posted January 15, 2016 CRF only Reply - We are not hearing these kinds of reports in numbers. We've read some of them online but nothing that would indicate this is a general issue with this motor. Keep in mind this is the same motor that is in the CBR250R and so it is tried and tested for long miles. Seems not to be any issue over the Pond. Are those bikes built here, or if built elsewhere are the parts being used from the same supplier ? Link to comment Share on other sites More sharing options...
thaiguzzi Posted January 15, 2016 Share Posted January 15, 2016 Re, the op. How do you change a cam chain in 15 mins? Split link? Link to comment Share on other sites More sharing options...
papa al Posted January 15, 2016 Share Posted January 15, 2016 So. Engine may make some noise. Maybe rattly chain type rattle? Does engine finally blow or lock.? or what? Is 1% expected failure rate of life of bike/ first year? or what. Do other Hondas, and makes do same? I think I hear a lire rattle from mine sometimes; shit. Link to comment Share on other sites More sharing options...
Richard-BKK Posted January 15, 2016 Author Share Posted January 15, 2016 Re, the op. How do you change a cam chain in 15 mins? Split link? Sure you can easily change the cam chain for a Honda CBR300R under less than 15 minutes, but if the cam chain needs to be replaced because it's damaged or worn you should also inspect the sprockets involved. Link to comment Share on other sites More sharing options...
hougourou Posted January 15, 2016 Share Posted January 15, 2016 My CB 300F had a nasty noise at first that at least to my uneducated ear could have been a top end noise. Nope, it was the sleeve that surrounds the bolt that holds the tank on the frame. Cut a mm off the bottom--noise gone. Photo attached. Link to comment Share on other sites More sharing options...
In the jungle Posted January 15, 2016 Share Posted January 15, 2016 1. The way I read the original post the whole story is hearsay. The family of the owner of the bike told him etc. The way I read the first post the OP did not speak to the owner or see the bike with the supposed problem. 2. I have just had a look at technical drawings of the CBR300 engine. Changing the cam chain in less than 15 minutes as the OP claims is impossible. Link to comment Share on other sites More sharing options...
ktm jeff Posted January 15, 2016 Share Posted January 15, 2016 The 15 minutes is for a cam chain change on the Benelli engine , i guess using a soft rivet split link. Changing the chain as a service item , as Benelli suggest , will reduce wear on the cam and crank gears , which are harder to replace. This is a good idea as it seems this engine has been designed for easy servicing , but i would be surprised if its every 13,000 KM , as suggested earlier. Failing to replace a worn or loose chain could indeed lead to an engine letting go. Link to comment Share on other sites More sharing options...
wow64 Posted January 16, 2016 Share Posted January 16, 2016 (edited) The single cylinder 250/300 Honda are noisy engines.. However my 300r has not missed a beat in the year and a half I have been driving it to work. If it lasts 2 or 3 years for the cheap price it's done its job and I will get a new one. Change the oil regularly and that's all I have needed to do.. Oh chain lube also. Edited January 16, 2016 by wow64 Link to comment Share on other sites More sharing options...
thaiguzzi Posted January 16, 2016 Share Posted January 16, 2016 # I can't see how one can change a cam chain in 15 minutes, unless it's a duplex/simplex chain with a split link. # Every Jap engine i've ever peeked inside has always had an endless hy-vo chain. generally good for a min. of 50k miles. # Every engine i've seen, twins, triples, especially in-line 4's, to change a hy-vo cam chain is an afternoons work, ie half a day. Minimum. Might as well check valve clearances at the same time. # A cam chain, especially a hy-vo, and with correct tension, running in an oil bath, should outlast a triplex/duplex primary chain, and especially a simplex final drive chain. # Changing a cam chain in a service schedule every 13k kms is just ridiculous. Link to comment Share on other sites More sharing options...
In the jungle Posted January 16, 2016 Share Posted January 16, 2016 The CBR has an endless cam chain and, if I have understood the engine drawings correctly, you have to do a complete engine strip to replace it. But I doubt you will have to do that for a very long time. Link to comment Share on other sites More sharing options...
GARYZX6R Posted January 16, 2016 Share Posted January 16, 2016 The CBR 250 I had had the noise problem. Sounded like there were marbles rattling around the cylinder head . Only occurred around 5500 revs. Its sounds like a very common problem which seems Honda have still not solved on the latest 300. Dont forget the release of the CBR 300 was put back a year due to engine problems. Not good Mr Honda .. Link to comment Share on other sites More sharing options...
Gnasher328 Posted January 17, 2016 Share Posted January 17, 2016 The Honda 250 engine noise is irritating at times but after nearly 30k Km and a 300 conversion mine still seems to be going strong and not getting any worse. I'm sure blanking off the supplementary exhaust air valve halved it, the reed valve was making a metallic noise. It is so throttle sensitive I could be piston slap or still some sort of resonance from the exhaust. In fact when I briefly fitted a Yoshi copy with large bore downpipe I'm sure it went completely. Link to comment Share on other sites More sharing options...
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