2008 AR210 Engine getting hot

[Sam Tocco]

Hello....I am new to the boating world and I could use some help from someone knowledgable with Yamaha jet boats. I have a 2008 AR210 that one engine gets hot (sets off the safety sensor and boat goes into limited RMP mode) while idling on the hose for about 7 minutes or so. The other engine does not appear to get hot running that long but I ussually turn them off after 7-8 minutes during my flushing so it may have also got hot if I left it running longer.

This is the first time I have had it out this year. My wife and I were in a bad accident last year so we have not been able to take it out until recently but I tried to start it in the driveway every other weekend or so. I am afraid to take it out with that one engine getting hot. I read numerous blogs online and did some of the easier tasks....checked for crimped water lines, changed spark plugs, put in new thermostats, etc.

Someone I know who is knowledgable with boats told me that jet boats get better water flow when they are in the water from the back pressure of the jets than on the hose so there is a fair chance it will not get hot while in the water. The cooling systems on these jet boats are something I am not used to diagnosing. Does anyone know if that is true....does jet boats get better water flow in the water than on the hose?

 

[Bruce]

Welcome Aboard!

Why are you running it on the hose for so long?

It is entirely possible that your hose is not providing enough flow to keep it cool for such a long time but it will be fine with full water flow in a lake.

Just to be certain, are you flushing one engine at a time and connecting the hose to the engine you are flushings port?

 

[Sam Tocco]

Thank you Bruce for answering. I appreciate it.

When I purchased the boat the sales guy went over how to operate the boat and told me when flushing the motors to run them for 8-10 minutes. I do one engine at a time on the hose so each engine gets the full pressure from the hose.

 

[Bruce]

The manual says to flush for 10 to 15 minutes at a "fast idle". I have never flushed for more than 5 or at anything more than idle.

I would put her in the lake and see how she does. The flow of water from the lake may clean out anything that might be clogging the cooling system or it may simply be that the hose flow is insufficient.

 

[AZDANSX230HO]

The manual says to flush for 10 to 15 minutes at a "fast idle". I have never flushed for more than 5 or at anything more than idle.

I would put her in the lake and see how she does. The flow of water from the lake may clean out anything that might be clogging the cooling system or it may simply be that the hose flow is insufficient.

And make sure the pissers are shooting out water, sometimes they can get clogged, I had a hornet build a nest in mine years ago.

 

[itsdgm]

Welcome @Sam Tocco and sorry to hear about your accident last year, I hope all is well with you guys now.

Just to be sure, you have been switching the flushing line from port side to starboard side when shutting down one engine and starting the other. Right? I could see how somebody might think that one line would do both engines, but that's not the case.

The only other thing that comes to mind would be a kinked hose behind the flush line connection. But you stated that you've already looked there.

One thing to do would be to run the good engine and see where and how much water is coming out of the pump area, exhaust outlet and finally the thermostat openings at the rear of the boat when flushing. Then compare the flow and water temp to the affected engine. That should show you if there truly is a reduction in cooling water.

Good luck and keep us posted.

 

[Scottintexas]

glad to have you on board and hear you are able to get back to boating,

this is from one of our members explaining how the cooling water flows in our engines, since yours is an 08 as his was, yours might also have some flashing left in the connector,

 

[Sam Tocco]

Thank you everyone for the information....I appreciate it greatly. I live in Florida so right now we are preparing for Hurricane Matthew but once that passed I will take a second look at the lines again to see if anything is blocking any of the cooling lines. I get good amount of water pouring out of both engines when flushing them.

AZDANSX230HO - I too had a nornet nest try to build a nest in those holes a while back. I took a peice of wire hanger and broke it up and then used my air compressor to blow the mud out of the hole. From what I can tell they do not appear to be blocked because on the hose I do get a little squirt out of them when I rev the engine while flushing. Since I have owned the boat I don't remember ever getting much water out of those holes while on the hose but I would get a good squirt out of them while running them in the water.

Dennis - yes, you are correct. The procedure I have been following is I start the port engine first then turn on the hose which is connected to the port water connector. I let it run at an idle for 7 minutes or so. I then shut off the water followed by reving the engine a couple times to push the excess water out and then immediately shut it off. Then I follow the same procedure for the starboard engine switching the hose to the starboard water connector. Since I have had the boat I have always flushed the engines as soon as I got home after taking it out on the water.

 

[AZDANSX230HO]

Thank you everyone for the information....I appreciate it greatly. I live in Florida so right now we are preparing for Hurricane Matthew but once that passed I will take a second look at the lines again to see if anything is blocking any of the cooling lines. I get good amount of water pouring out of both engines when flushing them.

AZDANSX230HO - I too had a nornet nest try to build a nest in those holes a while back. I took a peice of wire hanger and broke it up and then used my air compressor to blow the mud out of the hole. From what I can tell they do not appear to be blocked because on the hose I do get a little squirt out of them when I rev the engine while flushing. Since I have owned the boat I don't remember ever getting much water out of those holes while on the hose but I would get a good squirt out of them while running them in the water.

Dennis - yes, you are correct. The procedure I have been following is I start the port engine first then turn on the hose which is connected to the port water connector. I let it run at an idle for 7 minutes or so. I then shut off the water followed by reving the engine a couple times to push the excess water out and then immediately shut it off. Then I follow the same procedure for the starboard engine switching the hose to the starboard water connector. Since I have had the boat I have always flushed the engines as soon as I got home after taking it out on the water.

A good tip I learned a long time ago is to put golf tees in the pissers, that will keep the hornets out of there.

 

[rohlm50212]

Same Issue, 2015 AR210 with 25 hrs on the Engines, run with a hose at home without issues, heated water returns out the Exaust ports and no problems, when in the water, warm water comes out the pee holes when engines at 3000 RPM, but after 10 Mins of running stbd engine gets an overheat alarm, followed by the port after a couple minutes......Any good ideas? the boat has been stored for a year, ran weedeater line into the pee holes and they seem clear....Help please.....

 

[Scottintexas]

bad impellers, debris in your jet, debris on your intake screen,

something messing up the water flow between the intake screen and the engine since it runs ok on the hose,

any special boating conditions that might have extreme muddy or sediment in water? I'd probably pull the strainer screens on the nozzle first since both engines are having an issue,