IMO it's because of future emission concerns.

The big bores will be a dying breed unless they can reign things back a bit.

 

Here a interesting fact that I was not aware of... Everyone knows that the Grizzly and Kodiak had a 708cc motor from 2016 -2018; but did you know that during these 3 years the Yamaha Viking continued to have the 686cc motor? The viking has always had the 686. The Wolverine however went from the 686 to the 708 during these years just like the Grizzly & Kodiak, (except for the X4 which had the new 850cc motor). Makes you wonder how they were able to contiue with 686 for the Viking but nothing else, from the rumors of why they swithched to the 708. FYI, I got this information directly off of Yamaha's website doing Model History searchs.

 

Just sharing additional info. The Japanese tsunami happen way back in 2011. And like you mentioned the 686cc was produced threw out the 2016 - 2018 strech for the Viking SxS. In my opinion the Tsunami doesn't have much to do with the short 3 year 708 saga.

 

The unofficial answer to your question may be “yes” - Most people think Yamaha farmed out engine production that year. The 16’s have had some oil use issues. Yamaha rebuilds them if it’s bad. Not everyone has problems, but the percentage seems higher than with the 686.

 

Most people don't think that the engine was farmed out. The majority of people know that Subaru built the 708 engine for Yamaha welder engine plant was being rebuilt after the tsunami. The remainder of the original 686 engines were used to continue to build the Viking. The new 708 Subaru engine which Yamaha now owns that Subaru small engine plant, was used in the new updated grizzly + 700 Kodiak. After the short-term contract was up and their engine plant back into full production, they went back to their original 686 but also updated it to give it a bit more of a torque curve and to help comply with new emission standards.

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Just like above. Possible oil consumption issues with some, which yamaha apparently corrects.
My friend rides a 16, with absolutly no problems, hes at about 350 hours

Im on a 2018 with about 450 hours, no problems other than the things I have caused from being a wild man

 

That's some good hours on that machine their chum!!!!

 

One of our members on the Grizzly site (Reogem) has a 2013 686 Grizz with 22 000 miles on it. He racked up all that mileage in 4 years before switching to Kodiak 700 in 2017..... Freaken Crazy!!!!

 

Everything you guy’s mentioned makes a lot of sense. But what doesn’t add up is the tsunami was in 2011 so why did it take 5 years for Yamaha to start repairs on the factory? How were they able to continue 686 production for 5 years after the tsunami before making the switch to the 708?

 

That's exactly my point.

 

My guess is that they may of had a stock pile of 686 engines or were able to manufacture them on a limited basis.

They may of also wanted to try a different engine in the Grizzly and Kodiak platform but didn't have the tooling to do it at the time.

Only Yamaha knows the real reason why.

 

Only Yamaha knows the real reason why.

100% Agree

 

This is good stuff....
Exactly why my reply was only suggestive, filled with “May” and “possibly” words. Lol!!
I have been wondering though...
The old 686 was a 2-valve? And the 708 was a 4-valve? What about the 19+ 686?

 

All 686’s are 2 valve and the 708’s are 4

 

Incorrect . There as NEVER been a 2 valve 686. All have 4 valves.

 

Ok, thanks! I thought just maybe they brought a new valve train to the new 686.... guess not. At least, not a huge swing like 2v to 4v.

 

The 686 got significant updates in 2014. Compression ratio was raised from 9.2 to 10:1, they utilize a new better flowing head, all new fuel and spark maping, Completely new better flowing exhaust system witch utilized a a single exhaust header vs the older 07-13 twin header design.

Yamaha claimed more mid and top end power out of because changes including 30% better fuel economy. It was the first engine to have the AIS system and a catalytic converter built into the exhaust.

My 2019 Grizzly is basically the same as the 14 - 15 version of the 686 engine, with I'm sure a few revisions here and there.

 

If you really want to see what the best oil change strategy is for these machines you really should do a oil analysis to see what the oil is doing, the wear metals in the oil, and the oil break down.

While I haven't done it yet on my Kodiak I drive a diesel truck and according to the manufacture I should change my oil anywhere from 3000-5000 miles. According to the oil analysis I could stretch the oil change out to 7000+ miles. I did run it to 6500 miles one time and sent in a sample and they said that everything was looking good and to extend it out some more.

If you are interested the company is Blackstone Labs and they will send you a free sample kit. The analysis is around $30 US and the turn around is quite quick. For our Canadian members I am sure that there is a lab north of the 45th that will also do it for you.

 

I read a post where for the first time a reference to the engine changes stated that the new 686 engine had 'forged internals' . Can anyone shed any light on this subject. If so this would seem to give a bulletproof design when coupled with SOHC layout. Educate me.

 

Forged is what you want. That’s what all performance engines have. It’s the strongest rods / pistons / pins. It means it can take a licking. Doesn’t mean that the rings or cylinder actually wear any longer. Just that you won’t throw a rod or pin by ragging on it.

 

I did a search on the 686 engine and could find nothing on it besides the normal Yamaha stuff on the engine specifications in the sales brochure.

 

Understand but was unable to find any info as to whether the rods/crankshaft are in fact forged internals different from the previous gen 686 engine. 708 to the 686 changed back to SOHC from DOHC correct? This to me would imply change for reliability or for torque characteristics. Just looking to understand better.

 

This is on the Australian site and chances are the same for North America. All new Grizzly EPS released | Yamaha Motor Australia

New 700-class engine
For 2019, Yamaha’s engineers have boosted the performance of the big bore Grizzly EPS even further, with more useable power. Grizzly now runs a new liquid cooled 686cc engine with improved engine response and lower vibration, noise and fuel consumption compared to the current 708cc engine.

In order to achieve this, a number of internal engine changes have been made including revised bore and stroke dimensions, a low friction plated cylinder – was cast iron - and the cast piston is now a forged item. A new air intake improves engine output especially in the key mid-range area while redesigned engine mounts make for even smoother running.

So mentions starting in 2019, the 686cc engine piston is now forged whereas the previous generation 686cc engine has a cast piston.

 

Thank you. If the piston and cylinder liner has been upgraded one would expect that the rod/crank would be upgraded to forged components as well. Just wanted to know so I don't ignorantly repeat incorrect info. Thanks.

 

I would side on stating that it would be an assumption that anything other than the piston was forged. Having all of those internals changed to forged would be a marketing department's wet dream and I can't imagine it would be left out of a press release.

 

Hopefully the cylinder is not lined with 'BMW Nicasil ' what a disaster that was. LOL.

 

Now that makes sense to me. Also the use of forged rod and crank is most commonly utilized for higher RPM engines, since the engine changes Yamaha employed are advertised as improved low end and midrange it is less likely unless dramatic increases in torque are made. Not the case.

 

And the plot thickens...

I just did a comparison on part numbers for a 2109 Grizzly and 2015 Grizzly under the Crankshaft Piston section. All part numbers are identical, including the piston. If you click on the piston part, it states that part is good on Grizzly 2014/15 and 2019/20 along with the associated Kodiak 700 models for 2019/20.

So either the part numbers are incorrect, or Yamaha never mentioned anything about a forged piston starting in 2014. Seems very strange.

 

Yup all part numbers for piston, crankshaft , cylinder, and head assembly are the same between 14 and 19s

 

My money is on 'RUMOR' as I completely agree that the marketing department would be making it well known. These changes are more likely in sport bike/racing products obviously. Thanks for all the great feedback.

 

I'm going to bring my 16 in for a trade in appraisal within the next couple of weeks. Looking forward to parting ways with the 708.

 

Am sure that you will be very happy with the new 686. Seems to get better each time I ride her.

 

The 708 is a dual overhead cam design. The 686 is not. The SOHC produces more low end torque, but the DOHC produces more top end horsepower. The DOHC will win in a drag race!

 

Totally false.
The 708 will out preform the original 686, the new 686 has more midrange torque, the hp is identical. The new 686 bikes do supposedly have a 6% lower gear ratio. As far as a drag race, there won't be enough difference between them to make a difference. It will come down to the rider. Dohc vs sohc doesn't change the hp.

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