1.8L Timing Chain Confirmation

[ROGUE111]

I have a 2016 AR192 and had concerns regarding the timing chain issues, discussed at length here, on the 1.8 liter engines. Swatski posted he had been told Yamaha addressed the timing chain issue in the 1.8l engines built after 7/15 by putting in beefier timing chains consisting of 4/5 links as opposed to the 3/4 linked chain in models prior.

I popped the plastic cover off my engine last night and the label on the top indicated it was built 7/15 (of course). I went ahead and unbolted the top of the engine to reveal that my engine built in 7/15 did indeed have the thicker, 4/5 linked timing chain. I just wanted to confirm what Swatski was told by his Yamaha tech and hopefully put a few minds at ease.

 

[McMark]

When you pulled off the valve cover is the gasket an o ring or some type of reusable gasket?

Thanks,
Mark

 

[ROGUE111]

No gasket or o-ring, the cover just lifts up. This may help:

 

[haknslash]

It's not just the timing chain that was changed but this is the easiest way to confirm. I've only seen one report on greenhulk of an updated timing chain break and that was on a race ski IIRC. So far so good for the 2016+ upgrades . Ultimately time will tell. It took several years for some of the 2010's to show some issues. The 2014-15's seemed to much happen sooner so hopefully this is a sign they have fixed the weak link(s) ...excuse my corny pun .

Now my next mod for increasing longevity and reliability is to install a BOV to save my SC clutch.

 

[swatski]

Just to clarify, the way I understand this debacle, the timing chain part has changed for 2016 MY.
It is shared between N/A, SHO and SVHO models.
The old part is 94591-66152-00, new 94591-74152-00. Here is the visual:

14-15 Chain 3Link/4Link

16 Chain 4Link/5Link

@ROGUE111 - thank for the pics! Looks like you do not have that problem.


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[McMark]

@ROGUE111

I mean the valve cover not the plastic cover. I just don’t want to pull it then not have a gasket.

 

[ROGUE111]

@ROGUE111

I mean the valve cover not the plastic cover. I just don’t want to pull it then not have a gasket.

Yes sir, when pulling up the valve cover there wasn't a gasket or any type of seal. After removing the SP boots and little sensor at the stern end, there were 8 bolts to remove the valve cover. I pulled it up enough to snap a pic and put back down and bolted everything back in reverse.

Hope that helps.

 

[ROGUE111]

Well crap, I looked in the SHO service manual and apparently there is a "not reusable" gasket that must have stayed on the cover when i pulled it up.

Those with mechanic knowledge believe I should go back in and replace the gasket?

 

[haknslash]

If it were me I wouldn't reuse it.

 

[ROGUE111]

If it were me I wouldn't reuse it.

I think I'm with you on this.

 

[itsdgm]

Make sure to use yamabond4 when you replace the gasket as indicated in your pic of the service manual. Otherwise the cam "notches" will suck in and leak badly. Ask me how I know

 

[swatski]

I would ABSOLUTELY replace the gasket.

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[ROGUE111]

Make sure to use yamabond4 when you replace the gasket as indicated in your pic of the service manual. Otherwise the cam "notches" will suck in and leak badly. Ask me how I know

Thanks, will do. Anyone wanting to check their own chain, Yamaha Sports Plaza has replacement gaskets (item 6BH-11193-00-00) for $28.

 

[afdouble]

Well crap, I looked in the SHO service manual and apparently there is a "not reusable" gasket that must have stayed on the cover when i pulled it up.

Those with mechanic knowledge believe I should go back in and replace the gasket?

View attachment 65498 View attachment 65499

So, how do I go about getting a copy of that manual...

 

[ROGUE111]

So, how do I go about getting a copy of that manual...

You can view it online:

https://www.scribd.com/mobile/doc/202500839/Yamaha-SHO-Service-Manual

 

[afdouble]

You can view it online:

https://www.scribd.com/mobile/doc/202500839/Yamaha-SHO-Service-Manual

Thanks!

 

[Neutron]

If the gasket is soft and plyable you can reuse it but always apply sealant to the half round portions and and spot where there is a seam from different components.
You can always tell a good gasket when you place it down firmly and watch when you tighten the bolts it still squishes down further.
When the gasket sits completely in the cover it should be raised from the cover surface

 

[Noko]

Anyone know if the timing chain on the pre 2016 chain can be replaced with the new chain? It doesn't look like it would be that hard.

 

[Neutron]

It can but you need many other components. Since the sprockets are different you need those too and the crank sprocket is part of the crank itself. Cam sprockets too which i am not sure is they are removable or part of the cams, chain guides, tensioner.....
Lots of expensive parts. On Greenhulk forums there was a complete kit and it was in the thousands

 

[Neutron]

Here is the link and it shows included parts:
https://www.4-tecperformance.com/index.php?main_page=product_info&cPath=16_82_167&products_id=4050