AR190 Overheating cause- LectroTab? Impeller? Impeller Housing?

[bttally]

I have a 2017 AR190 that I have put over 100 hours on it in the last year with no issues at all. We usually run long distances when we are out and there have been several days where I have run two tanks through it in one day. I run 90% in salt water and I have run all the way from St. Marks, FL to Orange Beach, AL in segments to give you the idea of what I use the boat for. The last five times out running long distances wide open for over 45 minutes the heat alarm comes on. I shut the engine down and let it cool and then run again at lower speeds with no issues all the way home without any further alarms. After the second day I bought a temp gun and checked temperatures all over the engine and most were under 170 with only a few areas reaching 200deg on the bottom of the exhaust manifold. My most recent trip had the overheat alarm on after only 5 miles and only the last mile at WOT. This time my gun did show temperatures between 210-225 in several areas.

I do flush after every trip. I have ribbon delete and L13 cone installed. The intake grate is clear, the tunnel is sealed, cleanout plug seems to seat tight, and it has a strong flow out the pee hole while underway and while on the hose.

Thought 1: I installed Lectrotab Trim tabs back in March and they work great on the little boat, but this issue started since the install. Trying to trouble shoot I have left them retracted the last two trips and I still overheated. They hid up under the rear shelf so they do not drag when not in use. I will have to post more about the install once I figure out the overhearing issue. I assume this is not the cause.

Thought 2: After the third time with an alarm I pulled all of the heat sensors. I pulled the temp sensors(each has a different name) in the exhaust, the two from the motor and then the thermostat off the back of the motor. All looked clean and new and tested fine in a pot of water following the testing steps in the maintenance guide. The thermostat had some buildup from salt around the seal, but it cleaned easily and tested fine by opening at the right temp in my pot on the stove. I reinstalled everything and ran it on the hose 6 times with salt away to clean the rest out. It still overheated and this is when I had the higher temps with the gun.

Thought 3: Since my overheating has only happened after running WOT I started inspecting the impeller after reading on this forum about cavitation. From the back it looked fine but after pulling the pump I now see that the impeller has some nice dings and the impeller housing has a decent gouge. I guess I got a nice rock at some point. I have not noticed cavitation, but is is possible that this is causing my overheat at WOT? I know it has a strong flow through the cooling system while on the hose and while cruising but I don't know that I have checked while at WOT.

I ordered a new impeller and housing last night so once it arrives in a week or two I will be able to test it out, but I want to know if I am missing something else obvious while I have everything taken apart.

 

[bttally]

For anyone with a similar issue...I replaced the impeller and impeller housing 2 and went for a test ride. I rode 30 miles about 15-20 of those at WOT and no overheating alarm, which is better than the last 4 trips.

I stopped after a long run at WOT to check temperatures of the engine with the IR temp gun. Everywhere on the engine read below 180 deg F except the oil pump at the very front of the engine. If I pointed there the temp would read around 220-230deg. Does that sound normal?

 

[2kwik4u]

220-230 sounds like a normal "design temp" for an oil system. No idea if it's normal for this boat. Same for your 180-190 on the rest of the engine.

Keep in mind, heat helps separate salt from water. Once it overheated a single time, it will compound the problem.

Do you have a tow valve installed to ensure your salt away is going through the motor and not just back flowing out the intake? I was chasing a leak last year and was really surprised how much MORE flow I got from the pee hole when I plugged the water intake on the pump.

Speaking of the intake, have you checked/cleaned the strainer/filter on the raw water intake on the pump? As much water as you travel that could have some debris/clogging/buildup in there. It's an easy check by removing the 4 bolts on the port side of the pump. There is a teflon perforated piece held under that aluminum plate, and has an oring on both sides to seal. This is where the raw water is initially taken (pumped) into the system.

I've not run mine WOT that long, but I've run mine for more than 45min on plane at 6k+ rpm. No overheating issues to speak of. I was on glass smooth fresh water (Cumberland River), but I don't think that will have any real impact.

I have the same boat sitting in the garage. I can take pics of anything you need tonight.

 

[bttally]

Even though it seems to be better after the impeller and housing replacement, in the back of my brain I keep wondering if there is a clog somewhere because I would think the 68deg water would cool the engine down a little more.

I have not installed tow valves as I carry hose clamps but I have been reading about it and I will do that soon. I have really good water pressure at my house so I always see good water flow out all the outlets. I agree that it is worth a try to see if it will blast out anything else in there I may just use the hose clamps once first to see if it changes anything. While on the hose I have also gone inside and pinched each line with my fingers and I can feel the water flowing in every part.

When I replaced the impeller and jet housing I also took apart the intake strainer and it was completely clean. I have a few hose clamps that have a little rust so soon I am going to try to take the cooling lines apart and run a line through them while I replace the clamps.

I love this boat and we use it all the time. It is the perfect boat for cruising the gulf and sandbar hopping. I just want to make sure I don't get stranded in the middle of nowhere so I am trying to get ready before we begin our long long runs in June.

Thanks for you help,
Ben

 

[FSH 210 Sport]

When you checked your thermostat, did you check the height of the fully open thermostat? Thermostats are an item I replace on a car when the cooling system gets serviced.

Having said that, the fact you changed the impeller and sleeve and the problem went away I’d say you solved the problem. Any chance the ding in the sleeve is lined up with the intake for the cooling water?

I like the salt away process for removing built up salt in the engine by doing a soak with it over a few week period, and what @2kwik4u said about the tow valves providing more flushing water to the engine sounds like a good thing. Sounds like you take good care of your boat!

 

[bttally]

@FSH 210 Sport
I did check the height and it was within specs of the service manual. I actually did it twice on two different days just to make sure.
The ding in the sleeve was actually on the exact opposite side from the intake, but I assume by disrupting the flow on one side the air could be pushed to the other. Who knows.
I have run salt away through it 6 times in the last two weeks on the hose for 10 minutes each time. I use a bucket to collect the water and other than foamy water I am not getting any sediment or anything.
I even changed the oil one extra time eveb though it was done just 10 hrs ago and changed spark plugs just to be sure. Oil and plugs looked fine.
Hopefully I have got it fixed. Either way I now know this boat like the back of my hand. I will post an update if I make any of the changes. Also, I will post soon about the lectrotab install.
Thanks!

 

[FSH 210 Sport]

@FSH 210 Sport
I did check the height and it was within specs of the service manual. I actually did it twice on two different days just to make sure.
The ding in the sleeve was actually on the exact opposite side from the intake, but I assume by disrupting the flow on one side the air could be pushed to the other. Who knows.
I have run salt away through it 6 times in the last two weeks on the hose for 10 minutes each time. I use a bucket to collect the water and other than foamy water I am not getting any sediment or anything.
I even changed the oil one extra time eveb though it was done just 10 hrs ago and changed spark plugs just to be sure. Oil and plugs looked fine.
Hopefully I have got it fixed. Either way I now know this boat like the back of my hand. I will post an update if I make any of the changes. Also, I will post soon about the lectrotab install.
Thanks!

Sounds to me like you have solved it! Go forth and pin it!

 

[WREKS]

@bttally After you get done flushing, how long does the boat sit until you use it again?

 

[bttally]

@WREKS We use it nearly every or every other weekend from April to October. Over the winter maybe once a month.

 

[bttally]

220-230 sounds like a normal "design temp" for an oil system. No idea if it's normal for this boat. Same for your 180-190 on the rest of the engine.

Keep in mind, heat helps separate salt from water. Once it overheated a single time, it will compound the problem.

Do you have a tow valve installed to ensure your salt away is going through the motor and not just back flowing out the intake? I was chasing a leak last year and was really surprised how much MORE flow I got from the pee hole when I plugged the water intake on the pump.

Speaking of the intake, have you checked/cleaned the strainer/filter on the raw water intake on the pump? As much water as you travel that could have some debris/clogging/buildup in there. It's an easy check by removing the 4 bolts on the port side of the pump. There is a teflon perforated piece held under that aluminum plate, and has an oring on both sides to seal. This is where the raw water is initially taken (pumped) into the system.

I've not run mine WOT that long, but I've run mine for more than 45min on plane at 6k+ rpm. No overheating issues to speak of. I was on glass smooth fresh water (Cumberland River), but I don't think that will have any real impact.

I have the same boat sitting in the garage. I can take pics of anything you need tonight.

@2kwik4u
I went out tonight to inspect and plan tow valves but I can't reach the hose from the holes in the clean out tray. It is hidden under everything else in there including the deck drain. I searched the forum for your install and saw that you also mentioned that you couldn't reach from there but I couldn't find what you ended up doing. Did you just install the valve in the engine compartment behind the Y?
Thanks!

 

[2kwik4u]

@2kwik4u
I went out tonight to inspect and plan tow valves but I can't reach the hose from the holes in the clean out tray. It is hidden under everything else in there including the deck drain. I searched the forum for your install and saw that you also mentioned that you couldn't reach from there but I couldn't find what you ended up doing. Did you just install the valve in the engine compartment behind the Y?
Thanks!

I've actually not installed my tow valves yet. I might not. I bought one of these on the reccomendation of some other users here. Should be here on Sunday and I'll be running the boat on the hose this weekend as well. Hope to try it out before I get to the gulf this spring.

I absolutely can not reach any of the plumbing under the rear hatch. I can't get past my elbow in those tiny little portholes without serious abrasions to my upper arm. I have tiny biceps as well, so anyone that any heft in that area is just stuck at the elbow. Several members have added valves with extra hose length and ties them off in place where they are easily reached through the portholes. Not a bad idea, but probably more work than it's worth for me.

If I was to put a valve in place. It would be in the engine compartment just aft of the "Y" fitting. That is the main feed for the cooling system, and I think having the valve in the engine compartment makes the most sense. I've also thought of replacing the "Y" with a 3-port valve so I could switch between the hose feed or the raw water feed.

I'll let you know how the hose clamp works.

 

[WREKS]

@bttally Please, report back if the overheating problem persists.

 

[bttally]

I've actually not installed my tow valves yet. I might not. I bought one of these on the reccomendation of some other users here. Should be here on Sunday and I'll be running the boat on the hose this weekend as well. Hope to try it out before I get to the gulf this spring.

I absolutely can not reach any of the plumbing under the rear hatch. I can't get past my elbow in those tiny little portholes without serious abrasions to my upper arm. I have tiny biceps as well, so anyone that any heft in that area is just stuck at the elbow. Several members have added valves with extra hose length and ties them off in place where they are easily reached through the portholes. Not a bad idea, but probably more work than it's worth for me.

If I was to put a valve in place. It would be in the engine compartment just aft of the "Y" fitting. That is the main feed for the cooling system, and I think having the valve in the engine compartment makes the most sense. I've also thought of replacing the "Y" with a 3-port valve so I could switch between the hose feed or the raw water feed.

I'll let you know how the hose clamp works.

@2kwik4u
ok, sounds about right. I didn't think I would get my arm back when I was trying.

I read all the post about adding and extra loop around the motor to fit in a cutoff but I'm not so sure about that with the chance of lowering pressure (although I'm not sure it would). I'm going to mess with it as I replace the rusted clamps and see what I can do. The biggest fear is that I get to the ramp and forget to turn the knob the right way. It will only take once. The ramps down here are so busy you get rushed and that is when stupid happens. I have clamp pliers like that as well for towing, but I haven't used them yet.

 

[2kwik4u]

@2kwik4u
ok, sounds about right. I didn't think I would get my arm back when I was trying.

I read all the post about adding and extra loop around the motor to fit in a cutoff but I'm not so sure about that with the chance of lowering pressure (although I'm not sure it would). I'm going to mess with it as I replace the rusted clamps and see what I can do. The biggest fear is that I get to the ramp and forget to turn the knob the right way. It will only take once. The ramps down here are so busy you get rushed and that is when stupid happens. I have clamp pliers like that as well for towing, but I haven't used them yet.

Yea, I wouldn't touch those valves unless you're being towed. For the exact reason you mention. I would install them in the open position, and leave them unless being towed. If flushing however, I would consider a carabiner with a short strap to put on the steering wheel when the valves are closed. Just make it a procedural thing where you don't close the valve until you put the strap on the wheel, and you don't remove the strap until you're certain they're open. Like a "Remove before flight" tag.

 

[DrPhil]

What the heck are 'tow valves' and why are they important?

 

[bttally]

What the heck are 'tow valves' and why are they important?

Search the forums for lots of discussion about it. You have to either clamp the intake line or install a valve(tow valve) to keep water from being forced into the engine while being towed when off. We were talking about it because it also can be used when flushing to force water from going out the intake which increases the flow to the engine.

 

[HangOutdoors]

I've actually not installed my tow valves yet. I might not. I bought one of these on the reccomendation of some other users here.

I just bought the same one, it will be here on Sunday. I don't really want to install the valves and it would be a lot better than my vice grips.

 

[WREKS]

If the engines bio-foul, flushing will not help.Yamaha Jetboat overheating