Yamaha MR-1 High Output 4 Stroke engines

[Carlito]

This would be my first boat. What should I expect of this engine? This is Inboard engine? CAn I keep this in seawater for a season (say 4 months) before dry docking it or should I dry dock it after every use/weekend? Thanks.

 

[Bondo]

Re: Yamaha MR-1 High Output 4 Stroke engines

This is Inboard engine?

Ayuh,... Welcome Aboard,.... I've never heard of it,...

Got a Picture...

edit;... After findin' yer other post in the general boating forum,...
No, you don't have an Inboard, you have a glorified Jet-ski...
It's an Outboard motor, modified to run as a jet-ski motor...
Phil gave ya plenty of into about it, 'n the fact they don't take to wet slip storage...

I'll now move this to the Jet-ski forum...

 

[Carlito]

Re: Yamaha MR-1 High Output 4 Stroke engines

I have this link to the boat (not actually the specific one I am looking at). Cheers

 

[Ernest T]

Re: Yamaha MR-1 High Output 4 Stroke engines

The MR1 is the 4 stroke Yamaha used in all their waverunners and most boats from 2002 to 2008. It is basically a highly modified R1 motorcycle engine for marine use. After 2008 they switched to an 1800cc engine designed from the ground up for marine use.

The MR1 comes in standard (110 HP 8000 rpm) version and the high output (160 HP 10000 rpm) version ask about. Both versions of this engine are highly reliable with proper maintenance. Some waverunner owners have logged over 2000 hours with these engines.

Yes it is an inboard in all practical definitions. This engine has an open type of cooling system just like most other types of engines....that means it uses whatever water you boat in for cooling. If used in salt water, that means saltwater is circulated through the system. You need to flush the cooling system to remove the salt water. The longer times between flushing the faster the salt will damage the engine, and the shorter the engine life will be. This is true for other types of engines as well. That is one reason that guys that boat in saltwater prefer outboard engines.....they are self draining, and easier to flush, therefore last longer in a salt water environment.

Here is a quote from the Yamaha Owners manual: "Some owners plan to moor their boats seasonally, rather than keeping it on the trailer between uses. This extended mooring is not recommended. Proper flushing of the engine is not possible with the boat in the water.". This will be doubly true if you keep the boat in salt water. I've seen these engines totally ruined in one season of improper use.

Bottom line is the less time it spends sitting in salt water, and the more often you flush the system, the longer the engine life (and other components) will be. Guys that use these engines in salt water on their waverunners have learned to keep the engine coated in anti-corrosive spray, and do a through flushing of the cooling system after EACH use.

If you are looking for a boat that will be kept long term in salt water, I highly recommend looking at an outboard powered boat, and don't forget the bottom paint.

 

[Carlito]

Re: Yamaha MR-1 High Output 4 Stroke engines

Thanks...seems I?ll need to re-direct to outboards...
Nevertheless, there are plenty of boats w/ inboards in front of my summer house that stay moored for the season.
Most use is on weekends, so I guess they get the flushing done every monday.
How would that work?
Any recommended extra care for the inboard in case I go ahead and purchase open. As said, weekend use for about three months...with Monday flushing, remaining in the sea.

 

[Ernest T]

Re: Yamaha MR-1 High Output 4 Stroke engines

I hate to keep sounding negative. I have the MR1 on my waverunner and it has been perfect, but I maintain it religiously. Jet boats really shine in rivers and fresh water lakes where the shallow water capabilities give them an advantage.

Here are some other reasons jet boats re not the best idea for salt water even leaving them for short periods of time:
1. Seaweed can easily clog the pump.....suddenly you have no power and no steering.....not a problem for an outboard or stern drive.
2. Close quarters maneuvering is much more difficult with a jet unit especially in current and/or wind and waves. Learning to reverse one of these systems is a challenge all to itself.
3. Bottom paint is a necessity if you are going to be leaving a boat in the water unless you want a blistered, barnacle covered hull. Many of the jet pump components are metal cables and connections, and sit under water. They can't be painted like the stern drives on other types of boats, and will be constantly exposed to corrosion.
4. Jet boats are not designed to be wet slipped. The MR1 engine is self draining, but only if you pull it out of the water.
5. Other inboard engines have internal anodes and anti corrosive treatments designed to resist corrosion. Remember this is a modified motorcycle engine. Even a few days a week sitting in salt water without flushing can kill this engine in a few seasons.....I've seen this many times on improperly maintained waverunners.

I wouldn't consider a jet boat for salt water use unless I could pull it out of the water after each and every use. Letting the boat sit with salt water in it for even a couple of days is NOT a good idea.

 

[Carlito]

Re: Yamaha MR-1 High Output 4 Stroke engines

Clear enough. Really, thank a lot.
Will switch search...