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johnmh

Anyone heard of timing chain issues on the 2015 450?

30 posts in this topic

Where I ride KTMs and Hondas are common, Yamaha 's are somewhat rarer.  I do not know any local owners to ask so I thought to post here. 

 

My local shop (which sells gear and repairs bikes but is not a dealer) advised against a new 450 Yamaha on the basis that two other customers have had stretched timing chain issues.  One guy allegedly even required a replacement at 10 hours on his new 2015.  Both riders ride in the desert, spending hours at high RPM.  Apparently, the replacement timing chains quickly stretched as well.  

 

Has anyone had issues with this?  The magazines call the yz450f bulletproof; searches on the web do not turn up pages of stories on timing chain failures on new reverse slant cylinder yamahas.  If this was a major worldwide issue, there would be lots of info available (and likely Yamaha would have redesigned the tensioner for 2016 which they did not). 

 

FWIW, I only ride MX and was considering a 2016 450.  I did test ride a 2014 in the past and loved the suspension and the torque.   I think I will need to grow into the handling (my current bike is a KTM 250 SX 2 stroke so any 4 stroke seems weird at first).   

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So far, no one has complained of unusual difficulties with timing chains on any of the EFI YZ450's. 

 

The YZF in general has had timing chain problems all along, but they are fairly few, and normally related to stiff and binding links, rather than stretching, and that normally is a lube problem related to the user's choice of oils and how well he maintains it.  It's not a plague or anything, it's just one of a very short list of things that ever happen to the bike.

 

I have always recommended changing the chains annually as a maintenance item.  When I replace mine, they are very rarely stretched at all, and never stiff.

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Pushing close to 80+hrs on my 15 YZ450F and I haven't touched the motor. Bike runs perfect...

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Pushing close to 80+hrs on my 15 YZ450F and I haven't touched the motor. Bike runs perfect...

 

Checked valves yet?

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Checked valves yet?

Lol, nope. I'm so bad... But the bike starts and runs like a champ...

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Nice. What are your oil/air filter change habits?

Pretty diligent. Oil/oil filter every 8hrs, clean air-filter every time I think the old one is dirty. Running Rotella 15/40, Rekluse , 94 octane blah blah blah. Bikes good, dam good! Debating on whether to sink some bucks into it or buy a new KTM 450...

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What's going to require money on it at this point?  Besides the suspension.

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What's going to require money on it at this point? Besides the suspension.

Thinking some triple clamps, GYTR ignition cover, Cycra Shrouds, GYTR basket, exhaust etc etc...

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LOLZ  

 

About the only thing in there I see being worth any money would be the basket...you would be equally as well served buying yourself a new purse, some hair extensions and hardbound signed copies of the 50 Shades trilogy.  Maybe golf clubs.

 

If I'm buying anything for this bike it's gonna be a plate and an 18" rear wheel once I destroy the stock rims.

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LOLZ  

 

About the only thing in there I see being worth any money would be the basket...you would be equally as well served buying yourself a new purse, some hair extensions and hardbound signed copies of the 50 Shades trilogy.  Maybe golf clubs.

 

If I'm buying anything for this bike it's gonna be a plate and an 18" rear wheel once I destroy the stock rims.

 

Dude, I got a SM Pro 18in rim and spokes, slightly used, hit me up....

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Had issues with timing chain on my 2014 at 80 hours, It skipped one then two tooth

No interférence damages, was changing oil at 4 hrs, heavy clutch abuser,moto only

Switched for a 2015, changing oil at 2 hrs and timing chain at 40 hrs.no issues , did not not bother checking valves, switched for another 2015 new at 85 hrs last friday (2016 not yet in :( )

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Will do...

 

Just picked up a new OEM piston kit on EBay for $70.

 

The timing chains are $20 and it takes maybe an hour to change them.  Cheap annual insurance.  I love looking up parts prices for this bike and seeing how cheap the stuff is.  Valves are cheap, full head assemblies are cheap.  Cranks are normal priced.  It was one of the big deciding factors in buying this bike, since I plan on keeping this bike until it's literally no longer safe to ride.  Mostly because I haven't seen anything better come out yet...and I'm still paying on it.

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Interesting. So no defects with timing chain stretch, just annual changes of the chain? At how many hours does the service manual suggest replacing the chain?

I am 6'4" and find the Yamaha uh, roomy and long, Perhaps not agile. The suspension is amazingly plush, far better than my 250SX (even with kit ohlins suspension). The motor is fantastic.

2016s are 6 weeks away...

Thanks for the input.

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Interesting. So no defects with timing chain stretch, just annual changes of the chain? At how many hours does the service manual suggest replacing the chain?

I am 6'4" and find the Yamaha uh, roomy and long, Perhaps not agile. The suspension is amazingly plush, far better than my 250SX (even with kit ohlins suspension). The motor is fantastic.

2016s are 6 weeks away...

Thanks for the input.

2016s are already sitting in dealers up here...

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 At how many hours does the service manual suggest replacing the chain?

 

 

The manual makes no mention of an interval.

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I have a 14' 450 (same engine at the 15 i beleve) and have 60 hours on it about 20 in the desert and the rest on the track i change the oil every 5 hrs with maxima extra 4 10 40 and a oil filter every 10 hrs i checked the valves at 58hrs still in spec about in the middle of the adjustment range has not changed since i first checked them at 10 hrs ..air filter cleaned every ride. Only maintenance ive had to do is tires greasing and its time for new sprockets and chain. I plan on puting in a ned piston and cam chain at 80hrs. I have some pics of the condition of the top end at 58hrs. Only thing i recommend is relocating the valve cover breather tube and puting a breather filter on the end as dirt was making its way into the pocket were the breather enters the valve cover...no damage has occoured. Great bikes

1438705432374.jpg

1438705490280.jpg

1438705547399.jpg

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I have had problems with my 2013 yz450f. The 13's also have the reversed slanted engines, but as far as I know there were some changes to it with the 14+ models. But I got my 450 used from a dealership with low hours, and I have had problems with the timing chain. I do regular maintenance and take care of it so it wasn't from lack of that. But with the yamahas timing chain, its 20 bucks for an oem so its definitely cheaper. My timing chain stretched and slipped when trying to kickstart it, and when that happened the kickstart just locked up so I thought it was the crank or something much worse. tore into it and realized the timing was way off then did some research and found that the older model yz450s had that problem but couldn't find anything with the newer ones. Much easier fix then I had thought, but what a video on the proper way to start a yz450f if you get one. If you kick it hard every kick your going to screw something with the reversed engine, I has to be top dead center at the beginning of the kick

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 If you kick it hard every kick your going to screw something with the reversed engine, I has to be top dead center at the beginning of the kick

 

Sorry, that's not accurate.

 

In the first place, the point in the rotation where you hit "the hard spot" is not top dead center (TDC), it's the start of the compression stroke.  With automatice decompression, that's about 20-25 degrees before TDC, and 10-15 before ignition happens at that speed.

 

Also, the engine isn't reversed.  The head id reverse oriented, but nothing about the rest of it is fundamentally any different than the YZ400F, except for the angle of cylinder inclination.

 

But more importantly, there is nothing you can do with the kick starter that can damage a healthy YZ450 under any circumstance.  When timing chains slip during starting, it almost always results from a combination of a chain with stiff links, and the engine kicking back as it fires.  As the engine cools, slack forms in the cam chain because the whole top end assembly shrinks.  The tensioner is not designed to apply a very great deal of pressure to the chain, only to immediately take up what ever slack it finds on the back side.  If the links rolling off the crank are too stiff to straighten out freely, they will create a false tension on the back run off the chain and prevent the tensioner from advancing. If the engine kicks back, or bounces off of compression while that condition exists, the pull on the chain will reverse, the stiff links will pull out straight, and the chain will loosen over the exhaust cam, whereupon it will be likely to slip.

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