Suzuki df70 overheat and over rev

[NJCoastFlyFish]

I own a 2007 Suzuki df70 that just went in for the 20hr service and I had the dealer install a stainless prop. The new prop turns 5500rpm with one person on board. Today with four people on board the engine would not run at 4000rpm consistently without the overheat alarm going off. This is the first time I had this problem and the only thing that has changed was getting a new prop and a 20hr service. At 3500rpm the boat could run all day without the alarm going off, but more than 10minutes at 4000 and the alarm will sound. I also had the overheat alarm AND over rev alarm sound because the engine was tiltled too high running at speed while running over a wave. I understand that the overrev would cut power to the engine but then the engine also overheated. I am not sure what to make of this problem.

Could this problem be that the dealer installed a prop with too much pitch and a heavy load causes overheat or do I have an engine cooling problem? The weird thing is this problem does not exist with the boat loaded light but for some reason the engine is running hot. Before I bring it into the dealer I want to know what i'm in for. I also want to take it out tomorrow to see fireworks but don't know how serious the problem is and not sure if I should take the boat if i'm dealer with a potentially threateneing problem.

The other thing is the engine does NOT stay overheated. As soon as power is cut I can throttle back up for 3500rpm and run there without overheating. If I run it back up to 4000rpm the temp buzzer comes on, cuts the power, and I have to start all over again.

 

[NJCoastFlyFish]

Re: Suzuki df70 overheat and over rev

Would running the engine on plane in shallow water, just shallow enough to kick up mud cause the water inlet to get clogged and the engine to over heat? I now realize no matter how overpropped it can't cause the engine to overheat.

Is the suzuki engine temp sensor designed to stop before causing any serious problems or do I have to worry about long term damage now that the over heat alarm has come on a total of four times.

I have also tried to get in touch with my dealer because I am still under warrantee but they have yet to call me back- Tom

My main concern is using the boat until I can get in contact with the dealer, but I noticed yesterday it ran fine but the overheat alarm came on once, and when I went to check water depth I was in 2ft of water with a muddy bottom even though I was smack in the middle of the channel, I noticed other bigger boats in the same spot getting stuck to so I put two and two together and thought maybe debri in the cooling system is the problem?

Any help?

 

[Rancherlee]

Re: Suzuki df70 overheat and over rev

If you get sand/muck in the intake it will chew up the waterpump impeller pretty quick. You also need to drop down 1" on the pitch to get your RPM's up to about 5800-6000rpm running empty with 1 person. With a stainless prop you could have been running it right in the much without knowing it where as an aluminum prop would get the edge of the blades chewed up pretty quick.

 

[NJCoastFlyFish]

Re: Suzuki df70 overheat and over rev

The motor is new this season with less than 40 hours on it- Even if I did run it through the mud a little, do I have to worry about replacing the water impeller ? The mud is soft black mud, not sand so that might help a little.

I am thinking about taking it to the dealer and trying to see if the warrantee might cover this if I get another temp alarm-

 

[CDO]

Re: Suzuki df70 overheat and over rev

I also have a DF70 model 2003 with 107 hrs. I have taken my to the shop twice for this same reason. If I get over 4000 RPMs the overheat lite and the rev light will come on causing the engine to reduce back to idle. I will go back to the pee spout and feel of the water coming out of the engine and it will be cool. After it cools down the buzzers and lights will go off. I can run all day as long as I stay under the 4000 RPMs with no alarms going off. Both time I put it in the shop it cost me 400.00. This last time they told me after checking all the water channels and they were pumping OK the factory told them to tell me to purchase some salt water treatment and flush through the engine . I have used a half gallon and tried it twice in the water since and the overheat and the rev alarms will go off if I run at 4000 RPMs or higher. So I call the factory rep and he says that the dealer is missing something. However the dealer after exhausting everything they know they call the factor and the factory tells them the same thing. I am still not got my motor repaired and now the factory tells me I will have to carry my motor in for a tear down at my expense.After checking around it sounds like the factor has a problem and they are not wanting to address them in call backs.This problem is a lot bigger than you or I. I asked that we all e-mail the customer service or some one at Suzuki and raise cane about this issue.

 

[Mustang260]

Did you get this problem solved? I have a 2002 df70 And it’s doing the same thing

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