Page 1 of 2 12 LastLast
Results 1 to 10 of 12
  1. #1

    Yamaha’s 1.8l Marine Engine questions

    What is the history of this engine? How long has it been in use and at what point will Yamaha replace it? Also, how many valves per cylinder and is it a single or dual overhead cam? Any additional info you can tell me is appreciated. Just trying to learn about my ski as much as possible. Thanks!


  2. #2
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    39,390
    +1
    1,746
    Some of your questions are basic engine facts that should be findable online with straightforward searching.

    Broadly speaking, Yamaha has a stellar reputation for marine engine reliability, including their PWC 4-stroke engines. The 1.8 liter engine continues the line, in naturally aspirated HO (circa 180HP stock) and SVHO supercharged versions (circa 280HP stock, significantly more when tuned).

    You can expect the 1.8 liter engine to appear in future model years, probably for quite a long time to come. It is an excellent engine. Powerful, smooth, well regarded.

    Yamaha has continued to refine it from time to time, recently (2016) with better timing chain in the supercharged SVHO, and an upgraded supercharger wheel and shaft (2018 IIRC).

    I have two 2017 GP1800. Fast, strong, easily tuned. They have 130 and 140 hours so far, no issues at all with the engines.

  3. +1 by:


  4. #3

    Yamaha’s 1.8l Marine Engine questions

    Its dohc 4 valves per cylinder timing chain fresh water cooling taken from jet thermostatically controlled

  5. +1 by:


  6. #4
    TimeBandit's Avatar
    Join Date
    Jun 2016
    Location
    Tampa Bay
    Posts
    705
    +1
    149
    The 1.8L is a solid, reliable and proven "platform" for many Yamaha ski's (and jet boats) today. I say platform because the motor is produced in two variants - normally aspirated & super-charged - and while these are both 1.8L engines, the two are too much different to be interchangeable (i.e. block castings, fasteners, pistons, cams, etc...). You have to consider the two variants as two completely different engines, aka you cannot (feasibility-wise $$) "upgrade" the NA to an SC. In regards to the SC variant, they started out as SHO engines, while today have evolve to SVHO.

    The 1.8L is already the 2nd generation 4-stroke offering by Yamaha, aka replacement to the MR1 (1100cc) which also had both (edit:correction) lower HP and higher HP variants. First 1.8 hit the wild back in (edit:correction) 2008. Fast-forward 11 years, and this engine has been refined/improved through the years. Another advantage of having such a long production-run is the plethora of third-party components and upgrades on the market, as the 1.8L has been successfully pushed many times beyond it's OEM specification limits. I personally have heard of no rumors regarding the next complete engine replacement - yet I'm sure Yamaha has a very tight-lipped control on future R&D endeavors. Looking back at when the 1.8L took over the MR1's, the MR1's (NA) still remained in production for many years, until the now TR1 has replaced it. Therefore, even if a new 3rd gen 4-stoke large displacement platform were to debuts, I don't see the 1.8L being immediately discontinued.

    The 1.8L was designed from the ground-up (not adapted like the MR1) to be a "marine engine". Due to the 1.8L larger displacement, the motor's rpm range/limits 1:1 complement the inherent RPM range of the impeller, and as such the engine directly drives the impeller (as opposed to the old MR1 which needed a reduction gear transmission). The MR1, due to this extra drive gear was intentionally installed backwards into the hull - meaning cyl #1 is the rear-most piston, while the 1.8L has #1 up front. Even having 700cc greater displacement than the previous MR1, fuel consumption is virtually on-par with the respective variants due to these lower RPMs.

    Next notable distinction, is that the 1.8L is of wet-sump design, similar to automotive engines where the oil excess/surplus resides in the lower engine oil pan. This means, unlike the MR1, there is no need to complicate the oil pump assembly with an added scavenging pump, and external reservoir. The 1.8 has a crankcase oil/vapor separation chamber built-into the port side engine block, further reducing external component engine clutter.
    Main cooling path supplied by the jet-pump, 1st enters the lower exhaust manifold where it is pre-heated/tempered before heading into the cylinder block, then upwards into the cylinder head, and finally out the thermostat housing at the rear cyl head.

    I take it, by your screen-name containing "vxs", that you have the 1.8L NA engine. Just know that this is a very reliable and proven engine. The only major black-eye the platform has seen having great pain-threshold to the consumer was a stint of notable timing chain breakages between the 2013-2015, mostly spiking among 2014 SVHO models. It's enjoyed over twice as long in-service as the previous MR1 HO NA motor. It's also fairly easy to wrench on, and there are very good detailed service manuals available for it. You have a very large community (especially on GH site) whom know this motor like that back of their hand.
    I do not intend to inject any mis-information in my words, as I'm simply offering you a basic introduction to this great motor.
    Last edited by TimeBandit; 01-18-2019 at 04:43 PM. Reason: correction on MR1 variants

  7. +1 by:


  8. #5

    Join Date
    Apr 2015
    Location
    Wales, UK
    Posts
    1,040
    +1
    72
    Time bandit did you right the above? Or copy and paste it?

    Never seen a supercharged MR-1 and I own a 2008 1.8 sho motor is stamped as built 12/07.......

  9. +1 by:


  10. #6
    TimeBandit's Avatar
    Join Date
    Jun 2016
    Location
    Tampa Bay
    Posts
    705
    +1
    149
    Brain-fart : was implying the MR1 had two version as well : the regular MR1 -vs- the higher horse power HO'd MR1 (not SC).
    Yeah, I though 2008 might have been it too....
    Yeah I wrote it too quickly - I'll fix-it

  11. +1 by:


  12. #7

    Join Date
    Apr 2015
    Location
    Wales, UK
    Posts
    1,040
    +1
    72
    Quote Originally Posted by TimeBandit View Post
    Brain-fart : was implying the MR1 had two version as well : the regular MR1 -vs- the higher horse power HO'd MR1 (not SC).
    Yeah I wrote it too quickly - I'll fix-it
    Thought it was unusual .... but a blown MR-1 sounds like fun.....

  13. +1 by:


  14. #8
    volltrex's Avatar
    Join Date
    Dec 2007
    Location
    Jersey CI
    Posts
    691
    +1
    51
    Quote Originally Posted by HDAV View Post
    Thought it was unusual .... but a blown MR-1 sounds like fun.....
    MR1 had 3 versions..... Original 998cc in the FX, then 1052cc HO & also lower powered 1052cc in the Vx. Riva also produced a turbo kit but this was very short lived as motors kept failing. Both the 1.8 NA & supercharged motors are very reliable in stock form, with all the timing chain issues now sorted out. As always good maintenance along with regular oil changes, are the key to trouble free running.

  15. #9

    Join Date
    Sep 2015
    Location
    Oceanside ca.
    Posts
    231
    +1
    13
    What enhancements to the 1.8 L engine make it marinized and ready for salt corrosion resistance?

  16. #10
    TimeBandit's Avatar
    Join Date
    Jun 2016
    Location
    Tampa Bay
    Posts
    705
    +1
    149
    Quote Originally Posted by Thopper View Post
    What enhancements to the 1.8 L engine make it marinized and ready for salt corrosion resistance?
    Well, marine equally applies to fresh water applications.... stainless fasteners, use of anodes in the coolant path, etc.. are just some of the characteristics. But "Marine Grade" is largely based on its intended application, and that application is "constant/full loading at elevated rpms". My guess is an all-around more robust engine... oiling, larger coolant carrying capacity, etc... which all may also translate into different journal bearing specifications, crank, choice of rod design, pistons.

    In contrast, we do know the MR1 engineering was "borrowed" from the 1st gen YZF R1 engine (motorcycle). Yahama likely piggy-backed off 90% of that R1, and 10% added R&D to make it into a marine version (primarily the crank cases and exhaust castings). I really do not know if this included enhancements to the internals. Perhaps this fits better to your term "marinized"

  17. +1 by:


Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Yamaha Celebrates 50 Years Of Marine Heritage
    By Rustymuscle in forum The Watercraft Journal
    Replies: 0
    Last Post: 02-12-2018, 12:10 AM
  2. Yamaha Earns NMMA Innovation Award For ’16 TR-1 Marine Engine
    By Rustymuscle in forum The Watercraft Journal
    Replies: 0
    Last Post: 02-15-2016, 12:10 AM
  3. Replies: 0
    Last Post: 09-08-2015, 01:33 PM
  4. 2000 Yamaha gp1200r engine questions
    By m4c13k in forum Yamaha Open Discussion
    Replies: 10
    Last Post: 04-15-2013, 12:17 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •