SX230 HO questions

[bklake]

If this boat had a big block V8, I would be all over it. I like to think I'm not a red neck but the rumble of the big block stirs my soul. I grew up on a farm, nothing I can do about it.

So, I got to run the Yamaha a few times over the last week. We are having a cooling problem with the starboard engine. On the hose, it cools fine. In the water, it gets hot and sets off the warning light. I verified the overheat with my precisely calibrated hand. Right engine is much warmer than left engine. I watched a few youtube videos and I think I understand the cooling system. I need to remove the screen on the jet pump. Since the boat has been sitting for a long time there is a good chance something built a nest there. The boat is on a lift. I tried to put the kayak in the water but the racoon family now living in the kayak didn't appreciate my disturbing them.

While I look for another kayak or something, I'm trying to think through the whole cooling system. Are there any problem areas in the cooling system I can check? Thermostat? ports that clog? There were several posts about spark plugs but I think those are fine because it cools fine on the hose.

 

[zipper]

@bklakeDo check the intake screen for blockage. I assume while on the hose, you are not throttling up as much and long as you are on the water. also make sure that the water outlets on the starboard side just below the rub rail are open. Should be 4 of them. They may not flow at idle and need a little more rpms/time for water to come out. I make a habit of checking every time I go out. Last year after purchasing our Yamaha, I did not see water coming out of them on our first outing. Ended up being mud dobber wasps had plugged them up with mud/larvae. Had to use grass trimmer string to un plug. Been fine since. Here is the cooling system schematic. This is from my 07 manual it should be similar to 05. Yes there are thermostats.

 

[bklake]

Idle power only in the water. I have not had a chance to run it yet. It is a 20 minute no wake zone to open water so I need it to cool at idle before I take it out.

The pee holes are clean and peeing.

Any other know trouble points in the cooling? Passages prone to get blocked?

 

[Scott griffith]

Check your thermostats they can get clogged aswell and to prevent the dirt dobbers put some golf tees in the pee holes when your not using the boat

 

[Scottintexas]

it's fine on the hose but gets hot idling in the water,

it should be somewhere between the cooling inlet on the jet and the inbound water y-fitting (where flush hose meets the jet hose).

could have impeller issues/obstruction causing the water not to get the cooling inlet and because you've not tried to get out of no-wake you've not had the experience of a problem of vibration or not being able to get up to speed.

Did you watch buckbucks video in the FAQ about how MR1 cooling system works? if not, it will definitely will help you,

 

[bklake]

I'm going to dig into it today and see where the problem is.

The potential buyer is hesitating because he can't find a mechanic or dealer that works on these. I searched the dealer section for a dealer in Virginia Beach, more specifically, a mechanic and nothing turns up. Is there a list I'm missing? There is a dealer that just took over the Yamaha line. They state emphatically, that they will NOT work on this year of boat. I've been around boats my whole life and I've never experienced a dealer that refuses to work on boat that they are the authorized dealer for. Not sure how Yamaha views this position.

 

[Scottintexas]

A jetski mechanic may take on the work since it's the same engine just in a bigger body,

I'd try to take it out and run it at speed to see what symptoms show up,