Suzuki DF20A DIY yearly service.

[TwoHooter]

An old post #119 in 2021!

Originally Posted by beamishken

...I'd be tempted to run it in an acidic tank or if you cant get it circulating water then force an acid solution through the flush port. You can use acetic acid, oxcalic acid phosphoric or my favourite is brick acid remove the anodes first though rydlyme & barnical buster use hydrochloric acid ( brick acid) and phosphoric acid as their active ingredients & are sold specifically for flushing engines, both contain large amounts of very expensive marine water[emoji6]

That's what I'm now thinking of doing - check/change the impeller, possibly remove the thermostat, then run it on an acidic tank. I can buy 100% Oxcalic Acid crystals at the local chandlers or brick acid at the builder's merchant. I won't change the anodes, they'll benefit from the acid if they have a build-up of scale on them. On our big boat for whatever reason a particular anode sometimes won't have been working very well and gets a build-up of scale but still has 80% or 90% of the metal left - I put them in acid for a short time and back on they go (with a continuity test). Like the prop nut anode in the picture which was acidified to bring it back to life.

[Fenlander]

Re grease I just use a generic waterproof grease from the local chandlers.

Re diagnostics my kit came via Ebay from Eastern Europe, CD and leads. It was an excellent resource and I'd not really want to run a modern EFI motor without that resource.

Re anodes I seem to remember there is an internal one that's worth checking. Might give some clues as to how likely waterway issues might be. Oh yes it's pictured in post 3 of this thread. I must say for a year old OB kept in the garage when not in use I thought the Suzuki anode condition was poor. Far worse than other OB makes/models I've known.

[jeffstevens763@g]

Suzuki have a internal paint system I’d check before using brick acid etc.

[TwoHooter]

Originally Posted by jeffstevens763@g

Suzuki have a internal paint system I’d check before using brick acid etc.

I knew there would be a catch! I just knew it.

[paulbrown22]

Very glad Boating Mania managed to sort you out quickly - they've always been spot on with me including for some very random parts that you wouldn't commonly need to replace, but our sailing club Suzukis take a right hammering and lots of things get bent...! I've always found their prices to be good, so hopefully as Fenlander says the difference is just where you have the larger kit + fluids - when I bought the kit for my Suzuki 50 last week the fluids are what make the big difference if you're trying to compare online.

I bought my Suzuki diagnostics from these guys last year and so far it's been great for monitoring and checking things although thankfully nothing major has yet been needed beyond replacing a misfiring spark plug: https://www.ebay.co.uk/itm/184146982941 . You may not want that exact software version depending on the age of your outboard. For that sort of price I wouldn't be without the diagnostics, especially if the mother ship was a Nordhavn :-).

[beamishken]

Originally Posted by TwoHooter

I knew there would be a catch! I just knew it.

Brick acid wont harm the paint. I tried it on a pair of yamaha heads which had corrosino & loose paint & at first it looked like it was attacking the aluminium but it was actually just removing the salt buildup which was sticking to the bare aluminium, it did nothing on the painted areas, it attacks anything with lime or cement in it, mortar, concrete etc the main ingredient in rydlyme is hydrochloric acid, which is what brick acid & patio cleaner is.

[TwoHooter]

In haste - leaving for the long drive to the boat this morning.
Boating Mania are wonderful and the prices are OK. I never mind paying for good service, it's so rare nowadays. Carol knows a lot and Mike knows everything and is willing to help. Sadly he thinks I've got to strip the powerhead down. I almost (not quite) wish I lived nearer Upminster!
More later.
PS: I'm not getting email notifications of posts here. I have entered the settings but it's not working.

[TwoHooter]

Well I got to the boats (mothership and RIB tender) on Sunday. On Monday I had to work on the big boat, servicing the watermaker (19 years old like the rest of the boat but it's worth maintaining carefully because a new one is just shy of £10k), did various other jobs, planned a passage Plymouth-Falmouth with OK weather forecast.... then Tuesday morning the weather was nothing like the forecast and we postponed, went walking instead, and our 1 year old car failed, so we had the fun of an AA callout.

I spent today studying Fenlander's notes, watching Youtube videos, going through the service kit from Boating Mania and matching everything to the exploded diagrams in the Parts Catalogue. If anyone else uses this thread in future it might be worth checking the part number of the service kit which was 17400-89810 in 2017 (post #31) but is now 17400-89812
Questions:

1. There are only 2 anodes in the parts kit but the Parts Catalogue lists 5 for this engine (6 if it's a long shaft). I'm concentrating on the waterpump at the moment to see if I can get water circulating but for future reference I'd like to know why there are more anodes than supplied in the kit.
2. @Fenlander – this is a crucial question - when seating the impeller you said to turn the drive shaft clockwise. Is that looking down from above? I think it must be, but if I get that wrong...
3. Timing belt. Here's another moan about the professional service I had - I told them the engine serial number and asked them to do everything necessary. They missed the timing belt on a 5 year old engine. And the same thing happened at the second place, they never told me the timing belt is a 4 year replacement item. So I'll take the risk and Do It Myself. @Fenlander - You spoke about this but never described actually doing it, and I wonder how it went and what tools you ended up using to pull the flywheel? I think the puller kit you mentioned might still be available: https://www.ebay.co.uk/itm/381594948531

[Fenlander]

Re anodes time has blurred my memory that there were more needed than in the kit but I think there is just the one internal and that's the crucial one. The externals are easy to keep an eye on.

Re the shaft turn clockwise looking from above. Always my convention to refer to direction as you look at the item when carrying out the operation.

Re the timing belt I sold the engine 2yrs before this was due. I have various pullers here so never had to consider which specific one I might end up with had I done the job. Easy job once the flywheel is loose anyway, certainly compared to most cars.

[TwoHooter]

Thanks Fenlander.
I have the bottom unit off and there is nothing wrong with the impeller. It was replaced almost exactly a year ago according to the invoice and looking at it I believe that job was done. I've seen enough impellers on different engines to spot a bad 'un.
What I don't understand is that the impeller housing, the stainless steel cup in which it sits, is oily. And when I dropped the bottom unit a bit of oil came after it, some drips quite fast, then slowed and stopped, not much, about half a teaspoon, but I wasn't expecting it. It's not mentioned in the manual or on any videos I've seen and I've never seen an oily impeller housing before.
I'm running out of time so I've got to replace the unit (with new seals and impeller from the kit), but I'm perturbed.
Oil or no oil I'm going to put a little grease on the drive shaft splines.

[jeffstevens763@g]

So is the pump pumping water into the gearbox?

[Fenlander]

Is this clean gear oil or blackish oily deposits from combustion?

[TwoHooter]

Originally Posted by jeffstevens763@g

So is the pump pumping water into the gearbox?

Don't know yet. The gearcase (what I have been calling the bottom unit) has gone back on and so far as I can see everything is where it should be, nothing is damaged. I can't see anything that might stop the impeller drawing water in from the bottom inlets (I took the strainers off to check).

I thought about trying the trick of putting the cordless onto the drive shaft to see if the impeller pumps but decided it wasn't necessary.

The advantages of doing this, at the cost of an unnecessary water pump kit, are that I now understand most of what goes on in the gearcase (not the actual gearbox, but everything else), and I'll never have to pay anyone else to check or change an impeller again.


Going to try running it in the tank again tomorrow.

[jeffstevens763@g]

If I’m right the oil is from the gearbox so the seal has been compromised the pump finds this to be an easier path to travel hence no telltale and reduced cooling water. So the oil will me milky and if you remove the top plug and pressurise the gear box it will blow through the seal. Omo

[TwoHooter]

Originally Posted by jeffstevens763@g

If I’m right the oil is from the gearbox so the seal has been compromised the pump finds this to be an easier path to travel hence no telltale and reduced cooling water. So the oil will me milky and if you remove the top plug and pressurise the gear box it will blow through the seal. Omo

That does not sound like good news but I'm grateful. I will investigate.

Meanwhile, back in post #115 Da_q-ban_one said that to remove the thermostat housing he had to remove the throttle body and I think mine is the same - I cannot get a tool on to the bottom of the 3 bolts, see pictures. I'm not sure I'm the right person to remove a throttle body.

[Fenlander]

There is nothing special as such about removing the throttle body but are you sure that needs doing. The manual shows removal of the pull start assy and the black plastic intake trunking/silencer which isn't too bad.

Just be sure to avoid strain on any of the electrical connections. True it is damn tight for spanners in that location. I always have spares I am willing to sacrifice with cutting short, bending or grinding bits away and then you can often get in seemingly impossible places. Also a good 1/4" drive set with multiple short extension pieces and knuckles.

[TwoHooter]

@Fenlander - I'm lucky to have a complete set of tools on the boat and I'm used to making special tools. I'm now thinking I might get at it it with the recoil unit and exhaust silencer off. I had to deal with business today so no more progress yet.

[TwoHooter]

Took the lower unit off today, removed the impeller housing, and tried pressurising the gearcase to see if any bubbles appeared around the drive shaft seal - none did. Drained the oil, watching it carefully, and let it settle in a clear plastic jug. No water. Not a drop. I'm pleased I haven't had water in the gearcase but frustrated that my original problem remains unsolved!

[Fenlander]

This came up on Youtube when I was looking for something else. I thought it a clear procedure for checking and setting the valve gaps which I covered in less detail in post 11.

https://www.youtube.com/watch?v=tTHDLLkK3Do

[A1an]

Originally Posted by Easedalenovice

If it ain’t broke don’t fix it (Break it).

Loads of people on here who mess around with their engines in the name of servicing them are the ones who have issues

I don't come on this forum much these days but when I do it always seems to be you that's stirring the pot. Coincidence?

I doubt it.