Possible cooling system problems

[islandstyle57]

Thanks for the advice, I plan on checking the Tach connections...the dealer said they were good, I will check anyway, also the thermostat since they did not even look at it.

What did you think about my idea for pickling the water jackets for 24 hours with Salt-Away or the like?

 

[Cobra Jet Steering LLC]

Well I if it is crud that is causing your issue it may work but I honestly doubt it, I have seen
large amounts of sand in the water jackets around the cylinders cause overheating, sand in the water box even a broken baffle in the water box cause overheating but first you need to do checks on every place and the exhaust system, plus the function of the thermostat as suggested. And the cooling system for your exhaust system.
Then go from there.

 

[islandstyle57]

Last 2 trips in the Indian river I "powered on " my trailer due to high winds and rough conditions and I noticed that I stirred up quite a bit of silt, I won't be doing that again. To your knowledge, is there any way to blow the sand out, such as with compressed air or higher than hose pressure water?

 

[islandstyle57]

I am trying to avoid at all costs removing the engine and puling the head.

 

[Cobra Jet Steering LLC]

I would be surprised if you need to pull the head, I would NOT use water to clean the head or engine, I would do the heat test and possibly clean the filter at your jet pump where the water comes from the pump and travels to the engine, it may have crap in it and it is made to be taken apart. The biggest mistake I see people making is powering the boats in reverse while in shallow water as that stirs up the silt etc and places it in the intake grate.
More people have overheating issues after doing that maneuver than any other. If you go in salt water you should add some zinc anodes to your pump also, usually the one on the pump from the factory is magnesium for fresh water.

 

[islandstyle57]

Thanks for all the advice. I have only owned 1 jet boat before this one, a Yamaha XR-1800. I loved that boat, but my experience has mostly been with large I/O's and I am almost wishing I went that route again before purchasing this 232.

 

[Scottintexas]

let's tap the brakes on the buyer's remorse until we get accrue some documented facts.

Let's remember you haven't even tripped an overheat light on your gauge or message in YDS (assuming the dealer checked that and would have used it to support their $1,900. quote to pull the engine apart)

Get it out on the water and get some temp. readings on each engine and let's diagnose it from there,

 

[Cobra Jet Steering LLC]

ok if you describe exactly when and how your boat is acting up it may be of some help. When I had a bad heat sensor I exhausted all the easy things first, then using the non contact thermometer I realized it was not really overheating, just a bad sensor.

 

[Evil Sports]

Why not just replace that 9 yo salted thermostat as a maintenance item

 

[islandstyle57]

Scottintexas, OK, brakes are on hold, but the wife is still furious, this is not the pontoon boat that she wanted so I have to get the ($20,00.00 hole in the water) as she puts it back in the water, the sooner the better.
Cobra Jet Steering LLC, short synopsis; I took the boat in for annual maintenance since I do not have a YDS yet (on the way from Ebay today). During the normal routine the YDS saw an overheat condition on the port engine at 10 minutes of idling at 190F, but no light on the tack and no reduction in engine RPM's when they ran it up. They used an IR gun and determined that the engine block at the #4 cylinder was reading 190F, so that must be where the blockage was. They say they have seen it a lot, especially with salt buildup around the anode and in the exterior cylinder walls. They tell me they did not check the thermostat, did not check the sensors, did not pull the anodes, but did inspect the wiring harness and the tach. They want to pull the engine, pull the head, clean all the passages, replace the timing chain and the Tach, and button it all back up to the tune of $3200.00. I said no, I will pay for the annual maintenance check and pick the boat up and start the diagnosis myself.

 

[islandstyle57]

Thermostat replacement may occur after an inspection.

 

[Evil Sports]

Good luck and keep us posted on yer progress. Always like to hear the outcome on things like this

 

[Cobra Jet Steering LLC]

Sounds like a lot about nothing 192 is not really HOT by a long shot and the sensor could be bad, stay the course check the temp check the thermostat but if it is bad the entire engine would be the same temp basically so you had no issues until they told you it has a problem, hmmmm . If the back cylinder is running hotter than the rest it is usually caused by a blocked exhaust system so you may need to pull the water b0x and check for broken baffles or trash, sand etc

 

[islandstyle57]

Will do, thanks, and I will post results as I have them.

 

[Cobra Jet Steering LLC]

And it may have just been some dirt in the water supply line feeding the water box. You can tell by the sound when a water box is running without the proper amount of water in it, That engine will sound quite a bit louder than the other, since the water also muffles the exhaust noise. I hope I was able to be of assistance just keep in mind it's difficult to know for sure but I doubt you have any real problem with the engine.

 

[buckbuck]

@islandstyle57 I responded to your PM.
I think you are on a good path. Flush the boat well and I suggest you go a step further and replace the anodes and t-stats. Both are easy to do. Like @Cobra Jet Steering LLC said, 190 degrees is not hot. When I was having problems I was over 230. One thing I learned about the MR-1 motors is that trying to cool them after they are hot by idling does not help. Not enough water flow is produced at idle.
Also, thinking about it now, the shop said they had high temps while on the hose. I sometimes get high temps on the hose too. This is not uncommon. Much of the water simply flows backwards out the intake. Clamp the hose between the intake and Y-fitting and then see if you have a problem. The best way to check is hook up the YDS and go for a 10,000 rpm cruise while watching the temps. Keep us posted as we are here to help.

 

[islandstyle57]

Thanks buckbuck, I appreciate the comments/advice. As I get through each phase I will post my progress.

 

[4x15mph]

Glad you are thinking about looking at this further before dropping the $3200. This sort of thing is why people speak about boating as costing another thousand. It does not have to

190 is not hot like others have said. You can buy an Infrared thermometer from harbor freight for ~$20 and monitor the heat of your engine over the next couple of outings.

 

[islandstyle57]

I picked my boat up yesterday, got the IR from Harbor Freight this afternoon. Mothers Day activities started early so the rest of today and tomorrow are a bust as far as working on the boat, but there is always next week!

 

[Scottintexas]

maybe we should start a new thread for "what's your engine temps", I'm not very mechanical so I don't really know what's acceptable,
For instance if one cylinder is reading higher because a cooling line is blocked can it warp a head or blow a gasket if everything thing else is cooling and not triggering and alarm??

I had the boat out this weekend and thought I'd take a few temp readings with my cheap I/R thermometer just as a guide to compare to Islandstyle,
It appears my port engine runs about 20 degrees hotter than the starboard for some reason. Of course the temp. on the exhaust manifold after the water injection is about 20-30 degrees cooler than the block itself and even cooler the further back on the exhaust I went.

I was surprised the front cylinders of the engine 15-20 degrees warmer than the rear cylinder and each cylinder was slightly cooler as I worked back.

This is for a MR1- HO after a full day of tubing and temps being taken at no-wake rpms coming back in. Oil was at the Low level on the dipstick, water temp was about 70, air temp about 85