savagex

14 Yamaha 450 - 75 hours, engine work?

11 posts in this topic

I have a 2014 Yamaha YZ450 with 75 hours on it. I am thinking it may be time to get some motor work done to hopefully keep me going for many more hours.

 

I contacted Race Tech to talk about some options to consider:

  • 5 Axis valve job
  • Port and polish
  • Rebuild or replace the crank (apparently the 14 crank can be an issue?)
  • Hone cylinder, new rings

Does anyone have any thoughts on these mods?

 

 

And does anyone have any thoughts on Race Tech or other shops they would recommend in the Southern California area?

 

Thanks!

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Do a leak down...

Unless you have money you need to spend, I ask why?

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Do a leak down...

Unless you have money you need to spend, I ask why?

 

I will do the leak down test. 

 

I look at it as preventative maintenance. I dont mind spending some money to get another year of riding out of the bike. 75 hours seems pretty high to me, and my fear is that the motor may break causing a lot more damage to the engine and worse case scenario to myself.  So I guess I look at it as piece of mind.

 

As for the valve job and port and polish, that would just be nice to haves since I am there.

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I will do the leak down test.

I look at it as preventative maintenance. I dont mind spending some money to get another year of riding out of the bike. 75 hours seems pretty high to me, and my fear is that the motor may break causing a lot more damage to the engine and worse case scenario to myself. So I guess I look at it as piece of mind.

As for the valve job and port and polish, that would just be nice to haves since I am there.

I'm pushing close to 200hrs...

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Regarding the suspension, in what part of SoCal are you?  Unless you've played around with the suspension and still aren't satisfied, I'd work with what you have before I spent money on it, and I'd probably rework the shock before the fork.
 
As to the engine, the thing that tweaks my view of your question is that it's '14.  Ordinarily, I would totally agree with Monk that if there's nothing wrong with a leak down test you should just check the valve clearance and leave it alone.  It's wise to replace the timing chain on an annual basis or thereabouts, just as a preventative measure, but the engine isn't know for needing very much attention in the first 100 hours.
 
However,...
The '14 was the first year of the 4th generation YZ450.  The Gen4 is basically a Gen3 with a wet sump lube system and a change in the way the shift forks work.  Lots of other things were worked over in the upgrade, such as some head work, etc., and one of those changes was the connecting rod.  Follow that tidbit with the fact that Yamaha abruptly replaced the '14 rod (1SL-11651-00-00) with a redesigned unit (33D-11651-03-00).  Tidbit #3 is that there have been a small number of reports of small end rod failure in '14 models.  That is, such reports have been made of '14's, but NOT any significant reports involving any other model year.

 

Now, it would still be an assumption to conclude that the '14 rod is dangerously flawed to the point that they should all be replaced to avoid eminent doom, but it would be enough for me to consider an early tear down for whatever mods I might want to make and replace the rod in the process. Piston? Maybe, depending on what the skirts and ring grooves looked like.  On the one hand, it probably won't need one, but replacing it would add another 75 hours to the time 'til the next piston. 

 

The only actual facts I have on the "problem" with the rod are that the small end breaks open (as opposed to breaking off), and that there had been some unusual noise from the engine that wasn't one of the normal bunch of noises YZF's have always been known for, and that Yamaha felt like it needed more than a little rework.   Not much to go on. 

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Thanks for the info Gray. As for the suspension, that is already serviced and re-valved by Enzo, I really like what they have done to it.

 

 

To start, I will do the leak down and check the valves and go from there.

 

So for the rod, would it be possible to replace with the 15 or 16 rod in a 14 crank assembly?

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I'm pushing close to 200hrs...

What kind of riding are you doing?  I only ride MX in the southern California area.

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What kind of riding are you doing? I only ride MX in the southern California area.

GPs , offroad, MX, Open A/Expert...

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Sounds like a good mix of riding. In my opinion I would be very concerned(scared) going "A" speed with that many hours, but thats just me.  I am glad to hear it can last that long!

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So for the rod, would it be possible to replace with the 15 or 16 rod in a 14 crank assembly?

 

Yes.  Order the rod, crank pin, and bearing, all for a '15 YZ450F.  Crank halves are the same from '14 up. 

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Just over 200 hours on mine now (2014) and still going strong. Valves have NEVER moved, it's seen one timing chain and I'm getting ready to put in another, just cheap insurance. I also did a piston at about 110 hours but I honestly think it wasn't necessary at all after having a look at things.

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