Suzuki DF20A DIY yearly service.

Fenlander · 04 April 2017, 14:18

Last year in different threads I mentioned I might self service my Suzuki DF20A (which was new in march 2016) and to hell with the warranty.

Firstly I'd not been that Impressed with my local dealers 20hr service... then consider it would probably cost at least £400 more than me buying parts/oils to have the dealer do the four yearly services required within the five year warranty period (plus whatever the timing belt change would cost at year four) ... and the travelling to my nearest dealer to drop off/collect would amount to another £50 in diesel over that period plus about 8hrs of my time.

So I've just received the required bits and started today.

I ordered the complete service kit from Suzuki... plus the gasket to check the valve clearances which stupidly isn't in the kit... 4lit of Motul 10W-40 engine oil (half the cost of buying by the litre and should just about do four services)... two tubes of Suzuki SAE90 gear oil (again better value than one and enough for about 3 services).

The service kit contains an oil filter & its 2 O-rings, 2 spark plugs, impellor kit, 2 anodes and O-ring for internal anode housing, prop split pin, fuel filter, oil drain plug copper washer, 2x gearbox compressed card seals.

I bought the service kit as everything comes in sealed individual part numbered bags so I can just use what I need and then have the part numbers to replace what's missing for next year.

I'd already bought the (physical) workshop manual last year so have all the extra info that's not in the instruction manual.

Fenlander · 04 April 2017, 14:33

First job was to remove the engine cover... its rubber to the lower cowls... the cowl catch... and the 9 bolts to enable the 2 lower cowls to split.

The OB had been out in the sun for an hour so I was happy the oil would drain off without running it to warm.... this proved to be true.

The fuel filter and a few hoses needed moving aside to get to the oil filter housing cover so that gave me a chance to drain the fuel filter from its blanked bottom tapping... no water or debris so as that's an inspect item at 12mths it will be going back on.

I drained the engine oil into a measuring jug and was pleased after just a few minutes to get just over 1lit which I was expecting. In the jug the old oil looked dirtier than it had on the dipstick.

I changed the oil filter and used new O-rings from the kit (note there are 2... the outer housing one and a smaller one the filter seals against internally). A new copper washer was fitted to the drain plug and it plus the filter housing bolts were torqued.

Re-filled with a carefully measured 1lit of fresh oil... will re-check exact level on dipstick once it's been run when the whole service is complete.

Fenlander · 04 April 2017, 14:45

Next I checked the anodes which are an inspect item at 12mths.

The external one on the lower leg just needed a light clean. I took it off to do this and was glad I did as the bolt was so tight... with even a decent fitting hex socket trying to slip off... I reckon another year might have seen it a right pig to remove. I lightly oiled the threads before replacing.

The internal anode hides away under a cover just below the oil filler. You have to take the manifold sensor out before the anode can be fully removed. Its cover has an O-ring which is in the service kit and I replaced it. The waterways were totally clean but the anode itself was cruddy so cleaned that up too. The Suzuki spec is to change the anodes when they have lost about 35% of their volume. Mine had lost no more than 5% so the new ones can stay in the kit for future years.

Breather and fuel hoses are an inspect item.... they were all fine.

Also all nuts, bolts and fastenings are an inspect item so I just gave everything a look over... nothing loose.

Finally for today I removed the spark plugs which also are an inspect item at 12mths. They were perfect with gaps still to new spec so the boxed new ones will stay in the kit for another year.

To be continued...

breezeblock · 04 April 2017, 17:16

good write up what about a new forum section on diy services

willk · 04 April 2017, 17:38

Interesting re the weighing of anodes to decide status. I've been doing this for a couple of seasons but wasn't sure what was acceptable to leave.

Nice thread in the making. I'm sure the fact that now you have a public record of your servicing technique and schedule in the event of a warranty claim is entirely fortuitous...

Seaflyer02 · 04 April 2017, 18:30

A very good article and easy to follow.
Top man!

Fenlander · 05 April 2017, 22:15

Thanks guys. Lower unit stuff today...

Pump impellor is a yearly inspect and three yearly replace. Four housing bolts and gearchange linkage to remove to drop lower unit. To keep the gearchance in sync I counted the number of turns the locknut wound down to its stop before unscrewing the brass collar. Then I eased off the four bolts about 5mm before tapping with a rubber hammer. I find it easiest to keep the OB upright and put a few towels down for padding in case the gearbox comes off suddenly. Once I know it's free I pop one bolt back in to retain and tilt the OB so the gearbox with driveshaft will come right off.

Four nuts to remove the pump housing and withdraw from impellor. Unsurprisingly at just one year old there was no problem with the rubber blades and the stainless housing was free from scoring. The pump housing gasket had plenty of life in it too so all fine to refit. When placing the housing back on the impellor the driveshaft needs turning clockwise to properly settle the rubber blades.

I coated the driveshaft splines... the lower unit to leg mating faces... the four bolts... the two locating dowels... and the water tube interface with waterproof grease** and pushed the lower unit back on while (having put it in gear) jiggling the prop to in turn jiggle the drive splines into the powerhead.

Torqued the four lower unit bolts then the gearchange rod connection was re-made... remembering to take the lower unit out of gear first then set it up by putting the locknut back to its original amount of turns. Finally checked that the indexed neutral position on the gearchange lever did produce neutral on the gearbox.

**In the manual it says to use "silicone seal" on the gearbox to leg mating faces and bolts. There was none there from new when I took it apart and my own experience plus that of others on various forums says the last thing you want there is set silicone.

Fenlander · 05 April 2017, 22:38

Next the very straightforward gearbox oil change which is a yearly task. I drained it off over a lunchtime and found I had 300ml rather than the spec of 250ml. When I filled it up from the bottom it also took 300ml so the capacity must be over the theoretical spec. The Suzuki gear oil "sachets" are very thin walled which makes them far easier to squeeze than others (such as Quicksilver) I've used.

The drained oil was free of water, metallic particles and dirt which was a good sign.

Note the oil spec is a GL5 which some other brands (again such as Quicksilver) might not match. New drain and level plug fibre washers were in the service kit... I was disappointed to note at the 20hr service the dealers had put one of the plugs back with a generic hard plastic washer which risked not sealing properly and water ingress.

Final lower unit job was to remove prop and grease the splines... replacing with the new split pin from the service kit.

As it happened I put back the 10" pitch I'd had off for repainting after I polished it leaving a Scottish beach last summer... etch primer on the exposed alloy and a standard black gloss top coat.

The image with the shiny prop shows the "prop kit" I carry... spanner... split pin pliers... wood to block it against cav plate to prevent turning... and spare nut/washer/split pin.

Fenlander · 05 April 2017, 22:45

Note in post #3 I mentioned doing the standard check that all fixings were tight. I did come across something today though...

The steering friction damper when brand new would go from free to firmly locked but by the time I'd run in it went from free to as good as free. I just assumed it was a rubbish damper and as I always run with it free thought no more. But today I noticed the damper nut had come loose and re-tightened the full range of friction is available. Looks like a lock nut but without enough thread showing through to hold... so I locked it with a blob of paint.

Fenlander · 06 April 2017, 13:56

Top end jobs today... check timing belt condition... check valve clearances.

To do both of these the recoil start needs to be removed. To do that you need to remove/move aside the fuel evap box and its hoses... the no start in gear cable... and the air intake silencer. Then its 4 bolts and the recoil lifts off.

Turning the engine over in its running direction I examined the full length of the timing belt... all OK as new. (It is a bit odd after all the car timing systems I've worked on for outboards of this size not to have a belt tensioner)

The belt inspection is a yearly item and it needs changing at 4yrs regardless of hours run.

Fenlander · 06 April 2017, 14:11

Moving onto valve clearances (again a yearly item to check) various hoses... elec conns... and the two fuel pumps need removing or moving aside. Then there are 6 bolts retaining the valve cover. There are marks on the cam pulley which need aligning for each of the cylinders (at TDC) in turn to check the related valves. Three of mine were spot on mid allowed range and one was a fraction tight so I adjusted that one.

The cover gasket is thin metal and Suzuki advise changing each time. Despite its expense of just over £21 I did so as a leak here would be so annoying mid trip/holiday.

Replacing everything is straightforward and I took care to keep to the correct bolt torque figures. Important to remember to reconnect the no start in gear cable and adjust.

*When the valve cover was off I was interested to see the start decompression system. My last image is of one of the two camshaft "pivoted tabs" that at rest and at pulling over speed will slightly open a valve on each cylinder (guessing it will be the exhaust) to ease pulling over. Once the engine fires a weight on the tabs moves out due to centrifugal force and the tab moves away from the valve rocker allowing the valve to fully close.

Fenlander · 06 April 2017, 17:23

Image below shows the tools I needed to carry out the service.

Also now know costs. £13 of parts used that will need replacing to top up the service kit plus... £8.15 engine oil... £11.27 gear oil... £20.18 for valve cover gasket.... so £52.60 in all.

The Gurnard · 06 April 2017, 18:08

Great write up Fenlander ..and although I have a Yamaha..and service manual..I find it very interesting.

I too am doing all my own servicing..thus the warranty is now null and void. I didn't bother checking the impeller as I wouldn't expect any issue there yet. So good to see you saw no issues with yours.

I didn't check the valve clearance either..thinking it should still be ok..as this is only its second season..so question for you..did you find any needed adjusting ? If so I may check mine this year too.

Thanks for taking the time to write it as you go

jeffstevens763@g · 06 April 2017, 19:05

Spot on David very informative and well presented I totally agree with your desion to DIY service I had my first service at 6 hours which was at 1 month or as the book says 20 hours when it was done dealer had no software to give engine info and didn't even reset the hour duration to 100 hours whilst on holiday the warning lights came up whilst at sea for 20 hours not nice when your in enjoyment mode to then rack your brain thinking what do they mean I new but talked myself out of it and went back to shore at least you know what's been done once again great thread

Cheers

Fenlander · 06 April 2017, 20:13

Thanks guys. Just need to get it in the water butt tomorrow to check all my work's OK... plus check idle speed and timing. Then it's ready to go and some time planned out next week if weather is OK.

Gurnard you are quite right I could have left checking the impellor but I wanted to go through the schedule by the book this first time then in future years I might tailor the schedule in light of this experience.

Re valve clearances I used a .20mm feeler gauge right in the middle of the allowable range (.18-.22mm). Three were spot on an one a little tighter but it was probably still within range... I set it to the .20mm though so I knew they were all spot on.

spartacus · 06 April 2017, 21:01

Fantastic write up. I take my hat off to you because you're prepared to take a detailed interest in your engine and do things systematically. That's not to detract from marine engineers, many who do a damn fine job. Gives you an insight into how everything works which is invaluable when you're on the water.

duggie12 · 07 April 2017, 19:00

Cheers fenlander I've got a suzuki as well and was thinking of just doing the servicing myself and that info you have given will really help

I'm not using my 4 stroke that much these days because I bought a 2 stroke and don't fancy paying service costs for the 4 stroke which I'm not using it that much

I always wonder about the frequency of checks etc that are recommended by the manufacturer when something isn't being used much. For example do I really need to change the gear oil every year when I've only used it once in the season or can I just skip it and do it every 2nd year - ditto lots of other stuff. I suppose the frequency of checks relate to timescales and amount of use so not an exact science

jeffstevens763@g · 07 April 2017, 20:11

Kind of thinking the same duggie I have 23 hours on mine 2 years old in July only had its 20 service at 6 hours 1 month gear oil I suppose you need to cheack for water ingress but timing belt do they really need replacing at 4 years with low hours if looking as new? But that said my top & bottom bushes have gone so would be my luck for it to go pear shaped lot to be said for the old 2 smokes

duggie12 · 07 April 2017, 21:29

I know Jeff, I'm toying with the idea of selling my 4 stroke and my 9.8hp 2 stroke and buying a new 15 hp 2 stroke, will plane both my boats, only 1 engine to service and still light enough. Decisions decisions all the time with these inflatables

Fenlander · 08 April 2017, 14:18

As you say duggie it's not an exact science given varying use... but the makers have to give what they regard as failsafe timescales to protect themselves and their warranty.

I wanted to do this first service by the book so I was 100% sure of everything but will use common sense in following years. Having said that I will probably always change the engine and gear oils yearly as they are cheap "insurance".

The other thing I'll not skimp on is the timing belt change at 4yrs as rubber items can suffer age related failure regardless of hours run. Having one snap is a breakdown which I'd seek to avoid at sea... and on some engines when it snaps there can be expensive valve/rocker damage.