YZ450f 2010->2016 connection rod part #

[BOSARACING]

Hi TT,

 

Just become the owner of an YZ450f 2014 with 40 hours on it. I'm curious about the reason why Yamaha changed the part# on the connection rod from 2015. Below is listed the partsnumbers for the connection rods from 2010 to 2016. From 10 to 13 it's the same part#, in 2014 Yamaha changed the part# and again in 2015 - have anyone had an issue with the 2014 connection rods, pls. stated hours on your bike in your comments - thanks.

 

          Old part#                            Replacement#

2010  33D-11651-00-00                      33D-11651-03-00

2011     33D-11651-00-00                      33D-11651-03-00

2012     33D-11651-00-00                      33D-11651-03-00

2014     1SL-11651-00-00                       33D-11651-03-00

2015     33D-11651-03-00

2016     33D-11651-03-00

 

See

http://www.internationalmotoparts.com/oemparts/a/yam/53a99e16f8700220a4415a04/crankshaft-piston

 

[grayracer513]

There was one user here who had the small end go bad on a '14.  Scoring and a rattle noise, no breakage. 

 

That's the only one I know of. 

[drtrcr400]

180 hours on my 2014 and still going strong.

[DanielMerrick]

I had the small end of my rod go out on me after very low hours. When it happens to me I did lots of searching and found I wasn't the only one. A friend of mine that I ride with has a 14 aswell and it has had a hard life with over 100 hours.

[Bremer120]

The small end of my rod broke at 27 hours and took out the entire motor. Local shop that I purchased from was gracious enough to cover despite being almost a year later

[Armbarn sailor]

Not a common occurrence. Yz450fs are about as bulletproof as any mx bike ever made. Honestly this is the first time I've heard about a yz rod issue. Honda and Yamaha are very very durable.

[JS264]

Small end let loose on my '14 and destroyed the entire engine at 87 hours last week. Friend of mine had the small end let loose on his '14 at 30 hours.

[grayracer513]

That brings it to 4 that I know of.

[Bremer120]

I was going to make a separate post encouraging riders to report these defects to the dealership and/or Yamaha directly. It seems like if there is enough occurrences there may be a recall that may benefit us who own the 14. Maybe not, but if Yamaha updated the rod the following year I feel like they knew they may have messed something up.

Edited January 3, 2016 by Bremer120

[Into the sunset]

I'd like to hear more from high hour 14 owners without problems. If you have one please weigh in.

[drtrcr400]

I'd like to hear more from high hour 14 owners without problems. If you have one please weigh in.

My 2014 is just shy of 200 hours and running strong. I'll probably freshen it up in the spring.

[Bremer120]

I'd like to hear more from high hour 14 owners without problems. If you have one please weigh in.

Not really the question by the original author. I guess if you were seeking that you could make your own topic? I don't think anyone is claiming that the Yamaha is unreliable and I kind of feel like that's what you may have been getting at. However, I do believe there was an issue with some of the connecting rods used in the 2014 450 and the original poster was asking for real world experience of that.

[Into the sunset]

Not really the question by the original author. I guess if you were seeking that you could make your own topic? I don't think anyone is claiming that the Yamaha is unreliable and I kind of feel like that's what you may have been getting at. However, I do believe there was an issue with some of the connecting rods used in the 2014 450 and the original poster was asking for real world experience of that.

I have a new 14 sitting in a crate in my garage. What I'm "getting at" is what I can expect and if I should pull the motor before it's ever started and replace the rod.

[DanielMerrick]

What weight oil is everyone running ? I was running 10w40 Yamalube till my rod failure, a friend of mine with 120 plus hours runs 20w50 Yamalube and hasn't had an issue

[grayracer513]

Before you go too far down that road, let me just say categorically that the oil weight has nothing to do with it.  I've used 10w-40 oils 9 months out of the year for as long as I can recall and never had an oil related problem.  If anything, running a 50 would be more likely to cause trouble because of it not flowing through and over thee lube zones as readily. 

 

I wouldn't use YamahaLube, though.  Even so, there isn't much way the oil can be blamed here when the only difference between the '14's that have had this problem and the '10-'13's and '15-'16's is the rod.

[Into the sunset]

So far we have 3 owners that had failures with their personal bikes and 1 from a friend who hasn't posted. With all of the 14's that are out there the number is low depending on how many read this forum. Since the bikes have been out for two years the small numbers make me believe that the risk is low. I'm leaning to just running my new bike and being vigilant to any noise that might arise.

Bremer & Daniel thanks for your input!

Grey what oil do you recommend?

[DanielMerrick]

Before you go too far down that road, let me just say categorically that the oil weight has nothing to do with it. I've used 10w-40 oils 9 months out of the year for as long as I can recall and never had an oil related problem. If anything, running a 50 would be more likely to cause trouble because of it not flowing through and over thee lube zones as readily.

Definitely not blaming the oil, but in automotive when you run higher viscosity oil it slightly bumps your oil pressure up because it has resistance in flow through the various orifices and lube passages. This could prolong the life of a journal type bearing since it has a properly formed oil "wedge" between the surfaces. I'm curious if the bad Rods are bad because of the clearances and/or the material/bushing is to soft

[grayracer513]

Definitely not blaming the oil, but in automotive when you run higher viscosity oil it slightly bumps your oil pressure up because it has resistance in flow through the various orifices and lube passages. This could prolong the life of a journal type bearing since it has a properly formed oil "wedge" between the surfaces. I'm curious if the bad Rods are bad because of the clearances and/or the material/bushing is to soft

 

That is inaccurate.  In the lubrication of plain bearing surfaces, or rolling element bearings, for that matter, the volume of oil flowing through the bearing is a more important consideration than the pressure at which it is pumped (which actually does nothing at all to improve lubrication).  The simple fact that the oil pressure may be seen to rise with a heavier oil is a clear indication that the delivery of adequate volume is being impeded in fact.  It's different if you changed to a high volume pump and saw the pressure go up due to pushing more oil through the same circuit over the same time, but when you use a thicker oil in the same system and see a rise in pressure, it's a bad sign in reality. 

 

What carries the load is the film of oil that exists between the two surfaces, and increasing viscosity does not have a direct connection to the relative strength of that film in and of itself. The best way to maintain the film is to maintain a steady flow of oil through the bearing area. Chevrolet Racing found years ago that Chevy V8's were better lubed by 30 weight oil than by 40, even in racing conditions, and in fact, that 50 weight oils were actually likely to cause failures.

[DanielMerrick]

That is inaccurate. In the lubrication of plain bearing surfaces, or rolling element bearings, for that matter, the volume of oil flowing through the bearing is a more important consideration than the pressure at which it is pumped (which actually does nothing at all to improve lubrication)

Yes Pressure and volume are different but they have each a great effect on the librication system, Oil pressure with the correct volume keeps your "wedge" or film your two surfaces ride on. if the surface is worn allowing to much oil to flow it will decrease pressure but volume will remain the same and begin to wear the surfaces even further. A greater Viscosity does not create a stronger film but the added pressure would compensate for the incorrect clearances. When crank journals are worn on a v8 your oil pressure goes for a shit because the greater clearance allows the oil to escape faster then the pumps can output, but if you add some thicker oil it will be more difficult for it to flow through the worn areas thus increasing your pressure and having the proper film/wedge for the two surfaces.

[Bremer120]

I think oil viscosity could definitely lead to a failure if you were way off of recommended weight. However if that is the case with these 14 450s, with very low hours, then the tolerances are way off to begin with. A thicker oil could help to fill the void of a high mileage engine perhaps but I don't think using 20-50 would have gave me more time. I was using 10-40 when mine broke and that was acceptable per the recommended oil chart for the ambient temperature.

Edited January 6, 2016 by Bremer120