Suzuki DF20A DIY yearly service. - Page 7

jeffstevens763@g · 20 March 2021, 11:35

my 25 Suzuki needs a lot of water over the intakes before it will come out of the tell tale all sound advice cleaning the crap out which might take a while looking at the state of it.
hard impellers don't pump well a change is a must.

Da_q-ban_one · 20 March 2021, 22:43

Thank you all for your input, truly appreciate the support.
I did spin the shaft with a drill last night, and found no water being pumped. Then tried it again this morning after seeing your posts and what the video describes, with a deeper tank and water level higher above and closer to the housing, and can now officially confirm- it's a bad water impeller. I guess I'm a sitting duck, till I can get my hands on a new impeller (which frustratingly, NO ONE has in stock, locally). My parts, including maintenance kit, should arrive in 3 days time, so I will just have to patiently wait till then.

Again, thank you all for the suggestions and tips. I will definitely be flushing the system thoroughly, using various methods and remedies and hope for the best.

Aside from that, the outboard truly looks to be in "like new" shape, and I suspect it was used for very low hours. Perhaps just wasn't properly flushed after every single outing.

beamishken · 21 March 2021, 09:06

Quote:

Originally Posted by Da_q-ban_one

Thank you all for your input, truly appreciate the support.
I did spin the shaft with a drill last night, and found no water being pumped. Then tried it again this morning after seeing your posts and what the video describes, with a deeper tank and water level higher above and closer to the housing, and can now officially confirm- it's a bad water impeller. I guess I'm a sitting duck, till I can get my hands on a new impeller (which frustratingly, NO ONE has in stock, locally). My parts, including maintenance kit, should arrive in 3 days time, so I will just have to patiently wait till then.

Again, thank you all for the suggestions and tips. I will definitely be flushing the system thoroughly, using various methods and remedies and hope for the best.

Aside from that, the outboard truly looks to be in "like new" shape, and I suspect it was used for very low hours. Perhaps just wasn't properly flushed after every single outing.

If you realy want to try it you could flip the impeller over & try it with your drill again. I'd make sure the whole impeller housing is below water so it just has to push not pull water.
Flipping the impeller the opposite way might just give it enough stiffness to start pumping, just beware its possibly more likely to break the vanes off if its realy hard when it bends the other way. Dont worry about getting the vanes the correct rotation they flip once they see water pressure against them

Da_q-ban_one · 22 March 2021, 04:31

Thanks for the suggestion Beamishken! But frankly, I think at this point, I will just wait for the new parts to arrive- as I feel I may just be psyching myself out thinking I have a bad motor, or that it's beyond repair- when in reality, it just might be a bad water pump/impeller.
Again, even though it's not good to run the motor while simply using the flush port, given that it is not flushing the entire cooling system, when I first ran it using the flush port- it did not seem to get as hot.

That tells me that
A) the important bits (i.e., the cylinders walls and head) are getting water, and therefore benefiting from it- and staying at a cooler (running) temp.

and B) that the passages might not be as blocked as I initially thought they were.

The anode and thermostat were pretty gunked with crystalized salt, but they both cleaned up nicely, as well as the passages they sat within, with a bit of vinegar, baking soda and dawn dish soap mixture I had previously made to remove hard water, calcium and other mineral deposits from my bathroom walls and glass.
So to sum it all up- I feel hopeful that the motor is not beyond repair, but ultimately we'll see what's in store next, once the new impeller arrives.
I will keep you all posted

Cheers

Da_q-ban_one · 27 March 2021, 17:26

Update: It was in fact the impeller. Got my parts a couple of days ago. Installed the impeller, and ran motor (with fresh gas) in a vinegar, dish soap, Salt-Off solution for about an hour.

I also replaced the both lower unit gear oils and crankcase oil (mainly to install new seals/gaskets on the filters and fill/drain screws and bolt).

When I drained the crankcase oil (actually spilled it all over my kitchen floor, due to improper funnel usage) it had a bit of gas smell in it. This was odd as original owner claimed he had recently changed it. Now I suspect, he simply topped it off and it was the original 7 year old oil. I say this because I now recall that during purchase demo, he did not know what the 8mm hex bolt (i.e., drain bolt) "was for"? That would explain the slightly strong smell of gasoline the oil had.
I've also read some small 4 stroke outboards are known to accumulate a bit of moisture and/or oil in the crankcase if not ran at a proper higher RPM for a bit when out. It could also be that the Thermostat was stuck open, again not allowing for the engine to reach proper operating temps. Thoughts on this?

Fenlander · 27 March 2021, 18:34

When you get the diagnostic lead and software you'll be able to see far more of what the engine is doing.... and what it's done in the past.

Good news the new impellor sorted the pee water.

Da_q-ban_one · 27 March 2021, 19:02

Thanks Fenlander. Very true!!

I cannot wait to see what diagnostics reveal.

For now, I'm getting ready to take the pup and the Mrs. out for a cruise in the lake today. Hopefully, motor runs good under load and higher RPMs.
Will post update...
Cheers!

Fenlander · 27 March 2021, 19:13

Brilliant. Give us a full report with some images if you can.

Da_q-ban_one · 31 March 2021, 22:12

Sorry for the delay. So ended up taking it out with just my wife and I on board as didn't want to deal with additional stress of looking after and securing our dog, before, during and after the setup/takedown (plus the pathfinder was a bit cramped, after loading it with far too many unnecessary items, as the pics will show haha).

The Suzuki performed beautifully!! But I was not able to go WOT as it scared the life out of me.

I noticed a few things:
It's a very heavy outboard, so loading unloading can be quite uncomfortable.
It puts a lot of stress on the transom, and until I got used to it, it had me nervously thinking it would RIP right out of the transom.
Another thing I was quite unhappy about was the amount of flex it put on the setup with us two onboard. I dont know if I underinflated the floor and tubes, but it would cavitatate quite a bit and the the boat would flex and almost bend as it tried to get on plane. It would also rhythmically ride a wake or wave, and cause this cavitation.
I read another thread where several people have had this happen and it is suggested that the overinflated floor and tubes a bit to remedy this.
I guess I will have to go back and try this another time. I think I did just 6psi for the floor, 4.5 for the keel, and 3 for the tubes. I forget the exact rating, but I want to say it should've been 3.4psi for tubes 8 or 9 for floor and maybe 4-6 for the keel.
I wonder of cutting a piece of plywood along the shape of the floor and installing underneath the air floor might help..?
In any case here are some pics of my setup.

Da_q-ban_one · 31 March 2021, 22:15

Here are a few more pics..

Fenlander · 31 March 2021, 22:33

Is your Saturn an air or alloy floor?

How sure are you that your pressure gauge is accurate?

Yes I found the Suzuki an awkward lump to move about but they are light for a 20hp. Yes it has a good power response midrange and a bit of a non-linear response which makes it really surge when you open the throttle off a previously held cruise speed.

Da_q-ban_one · 02 April 2021, 05:02

It is an air floor. From what I recall, it calls for 6 psi, while tubes call for 3.4 or 3.6 and I'm not sure about the keel (but I think it was somewhere in between the floor and tubes' pressure, so around 4.5 psi...?)

I am using a pressure gauge that came with a pump for my inflatable kayak- not sure how accurate it is, nor what would cause it to give inaccurate readings, but I suppose I could test it with an electric two stage pump I have that reads in kpa and simply convert the readings to psi to confirm.

I will also have to take better pictures of the cavitation plate height with respect to the bottom of the transom when outboard is installed- and determine whether height and trim settings are appropriate.

Da_q-ban_one · 02 April 2021, 05:14

Another thing I was considering- since it is possible that the cavitation may be caused by an imperfect or pitted prop edge- perhaps the original prop is not the right size/pitch for my current setup and/or it is slightly bent/damaged somehow..? I will take pictures of it and post it.

It is a 9.25in x 10 and since it would probably be a good idea to have a spare, what size should I get? According to the website, they have 6 different sizes for this outboard 9.25 x (7,8,9,10,11 and 12).

Fenlander · 02 April 2021, 11:18

I wondered if it would be an air floor. They are the most prone to prop ventilation... the larger the SIB and the more powerful the outboard the worse this can become.

The first thing to sort out is being 100% up to pressure. As far as I can see online your floor should be 10psi, tubes as you say and keel 6psi. It is crucial you are running at these pressures to minimise ventilation problems. Bear in mind the water will be colder than air temperatures so you need to inflate... put the boat in the water and then recheck the pressures after a short while when its cooled a bit in the water. It is important you know your gauge is correct... either by being a good brand or in my case I happen to have three (one on elec pump and two more) and as they read close to the same I'm happy to judge they're about right. If one was quite different though I'd think it may be inaccurate.

If you are still suffering ventilation try different trim positions on the outboard and also changing the distribution of people/kit in the boat to alter the boat's basic trim.

A 10" prop is what I used mostly with my DF20 and I can't see that causing you problems. Yes a damaged prop would not help but normal small edge imperfections shouldn't be a problem.

Also consider engine height on the transom relative to the boat underside. If your AV plate is close to or above the underside level then this could add to the ventilation issues.

Musling430 · 08 June 2021, 21:34

What a great thread!!

Maybe you can help me:

My DF20A now shows the alarm for low oil pressure.

However:
- The oil looks good.
- The oil temperature seems fine.
- The oil level is correct.

Also,
-I checked the oil pressure switch
- I still replaced the oil pressure switch

The oil pressure switch does exactly waht it should:
- Show infinity when engine is running
- Shows continuity when engine is stopped

My conclusion is that the oil pressure is fine.

Taking a '11 model to the dealer seems like a lot of money for an old engine.

What do you people think?
Do I actaully have to change the ECM to get rid of the alarm?

BTW, the alarm has been there for 2 years now.....

Please help me :-)

Fenlander · 09 June 2021, 09:50

Hello and welcome to the forum. Is yours carb or Efi and can it be hooked up to a diagnostic?

Pikey Dave · 09 June 2021, 15:21

Quote:

Originally Posted by Musling430

What a great thread!!

Maybe you can help me:

My DF20A now shows the alarm for low oil pressure.

However:
- The oil looks good.
- The oil temperature seems fine.
- The oil level is correct.

Also,
-I checked the oil pressure switch
- I still replaced the oil pressure switch

The oil pressure switch does exactly waht it should:
- Show infinity when engine is running
- Shows continuity when engine is stopped

My conclusion is that the oil pressure is fine.

Taking a '11 model to the dealer seems like a lot of money for an old engine.

What do you people think?
Do I actaully have to change the ECM to get rid of the alarm?

BTW, the alarm has been there for 2 years now.....

Please help me :-)

Are you sure it’s showing an oil pressure alarm & not asking for an oil service/change?

Fenlander · 09 June 2021, 15:52

Ahh good thinking Batman.

jeffstevens763@g · 09 June 2021, 19:40

Yep try pressing the kill switch 3 times to clear

Musling430 · 10 June 2021, 07:19

Quote:

Originally Posted by Fenlander

Hello and welcome to the forum. Is yours carb or Efi and can it be hooked up to a diagnostic?

Yes, this is the EFI Lean burn model. I believe the 2011 was the first year the EFI was sold on the DF20.
So yes, it can be hooked up with diagnistics.

My problem with taking it to the dealer is that since outboard is now 10 years old, the cost with taking it to the dealer can very quickly be out of control and exceed the value of the engine....