Suzuki DT4 will not pump water with new water pump

fishon71

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I have two older Suzuki 4hp motors DT4 that will not pump water out of the pee tube. Both run like a top and have new water pumps. I blew compressed are thru and the tubes and all seems clear ? I?m stumped and wonder if I need to put the cylinder head or power head as it could be clogged up cuz these are salt water run motors. Any ideas, is this a common problem with these DT4?s - thanks
 

fishon71

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Re: Suzuki DT4 will not pump water with new water pump

Anyone have an idea - pulled head and cleaned water jacket - no better
 

fishon71

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Re: Suzuki DT4 will not pump water with new water pump

I'm lost on both of these - If I hook a garden hose direct to the water pick up line with the lower unit off it pushes water thru fine - seems pump does not have any pressure even though its new
 

James R

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Re: Suzuki DT4 will not pump water with new water pump

How are you testing. If you are not using a bucket or tub then the pump may not work.
You say that the pumps are new. What part of the pumps are new?
If you are just replacing the impellers and the cups or plates are scored then you will have poor if no pump action. If the seals at the top or bottom of the water tube are no good then you get no pump action. If the intakes are blocked then you get no pump action.
Go to brownspoint.com for a parts break down.
Hope this is of help.
 

fishon71

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Re: Suzuki DT4 will not pump water with new water pump

Yes, I have checked everything very closely more than once, even the guy before me could not make it work. I thought I found the problem once I cleaned out the water jacket under the head but no luck. Just replaced the impeller, housing & seals look like new, makes no sense. I have done plenty of water pumps without any issue. Last resort is to pull the power head and look under there for crud and check the rubber seal.
 

James R

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Re: Suzuki DT4 will not pump water with new water pump

Had a problem with one Suzuki where a piece of an impeller came off and lodged in the water cavity under the power head above the tube.
Pulled the power head and shonuff that was the problem. With the power head off you can flush out just in case there are other bits in there.
Oh!
Did you rotate the drive shafts clockwise as you pressed the pump housings over the impellers.
If not then that is most likely your problem.
Forgot all about that.
 

fishon71

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Re: Suzuki DT4 will not pump water with new water pump

I will have to get on these again soon - I have two with the same issue. Yes, a little grease in the housing and a clockwise turn on the drive shaft while putting back together - I'll be back
 

fishon71

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Re: Suzuki DT4 will not pump water with new water pump

Okay, just got back on this on today ....
1) I hooked a water hose directly to the pick up line without the lower unit, water flowed very well.
2) Put it back together and "wham" she is pumping water like it should.
3) I went to stick the rubber plug in the hole for the shift screw access hole, water stops pumping.

Seems the exhaust pressure is pushing the water back so it does not pump with the rubber plug in place. Motor is very loud with out the plug.

Any ideas, this is driving me nuts!
I have not pulled the power head, I guess that's next.
 

James R

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Re: Suzuki DT4 will not pump water with new water pump

Now I'm groping in the dark. It is not clear from the parts drawings how your exhaust vents but I think it vents thru a port at the rear of the motor along with the the exhaust cooling water. I don't think the exhaust vents down the leg. Just to be sure,where is the Rubber bung access that you mentioned located. The drawings I have looked at show an access panel in the side of the leg.
Of course it would help if I had the year of your motor.
 

fishon71

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Re: Suzuki DT4 will not pump water with new water pump

Hi,

The motor is 1987, I got the new gaskets today, everything has been cleaned and blown with air, all holes seems to be nice & clear, I even pulled the head again to insure clear passage. The exhaust just goes right out the bottom of the leg and that was all clear, this is really weird and I have two that do the same thing. The second one has not had all done to it like the first but will get the same treatment soon.

Updates to come ..........
 

James R

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2,660
Re: Suzuki DT4 will not pump water with new water pump

Ok. Either insufficient pressure from the pump, possibly intake blocked or still something wrong with the pump or lower tube seal, or sufficient pressure from the pump and it is being lost at the upper rubber seal or the head to housing gasket. If you think it is at the gasket could it be that the aluminum is eaten away and the water is bypassing.
To ensure a seal at the gasket use OMC thread and gasket sealer.
When you opened the side cover you found that the water flowed.
This indicates that the back pressure caused by the exhaust being closed off by the lower immersed in water was sufficient to back the pump water pressure up.
 

199675hpforce

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Re: Suzuki DT4 will not pump water with new water pump

Did you try and stick small straw in pee hole, crap gets in em.
 

fishon71

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Jul 21, 2002
Messages
575
Re: Suzuki DT4 will not pump water with new water pump

Problem solved - after pulling the powerhead on both engines the holes where clogged up for water passage. Also I found these are real finicky for water depth. They need to be submerged to the upper plate above the cavitation plate or they will not pump. Okay on to the next motor.
 
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