Mysterious shifting problem with Suzuki DF 20

[BGW]

Helmet, yes. The DF 9.9, 15 & 20 are the same motor except for the size of the (interchangeable) orifice in the throttle body and the computer. I have read the 9.9 & 15 computers are the same and the only difference for the 20 is that it has a higher redline. The parts are readily available. It does make the 9.9 a heavy motor for the power.

 

[BGW]

Part 3 is the detent for the shifter. It has a spring and ball mechanism that provides the positive engagement when you shift. So yes, take the motor off and do this in the boat or on a stand.

 

[HelmutSheina]

Thanks BGW. On the weight of the 9.9, all you can do is to compare with other manufacturers. Mercury detuned a 15hp 2 stroke down to 6hp at one stage and it was a ridiculously heavy 6, but good for pushing yachts etc, and I'd imagine the Suzie 9.9hp is similar. I was running a 6hp Tohatsu sail motor on a heavy cat and that was an impressive fuel sipper.

Because of the probable link to engine temp I favour the shaft over the detent as culprit.

Find some time to run it on ears or in a tank and isolate sections by disconnecting others. The biggest hassle will be if the powerhead needs to come off to access the shaft due to the lower cowling. If the cowling splits you're sweet. Manual will tell you.

 

[BGW]

The cowling splits, getting to the shaft and shift mechanism is easy. I don't think its the detent either but the OP said he wasn't sure what it was when he was contemplating dismantling it.

While it will take a little bit of time to strip it down, none of it is difficult or hard to access and is fairly logical.

 

[montero]

While I have no complaints about the engine's construction, the shaft and pistons are masterfully crafted.

Then the accountant orders the accessories to be built from **** and wire.

 

[montero]

And sometimes human life depend of stupid solutions .
I remember stories about the CCCP northern fishermens. They took three engines, two spares, but still didn't return.

 

[BGW]

Slight threadjack, but Montero, I agree with you about the Suzuki engines themselves. They were not the problem. The wiring system and many of the switches and accessories, like the starters, were complete junk. After owning several Suzuki motorbikes and a couple of their cars over the years, I was very disappointed.

Another issue is the dealer network. Even when there are dealers, like when I was still in the US, none I tried would work on the 'little' engines. One was honest enough to say "by the time you've paid our labor and got a few parts, you might as well buy a new one".

And then try to buy parts! It may be different now but when I needed a starter 6 months ago there were none available anywhere. I had friends check in Europe and South America, as well as searching the US. A few other small parts show up as NLA for a 4 year old motor... And had there been any starters available they were 1/3 the cost of a new motor. Not going to make the same mistake again. I've replaced them with 9.9 High Thrust Yamahas that have a good reputation.

 

[Russell Brown]

I haven't had time to bite into this yet. I'll haul the boat to my shop where all my tools are next week. Thanks again for all the help and I'll give a report on what I find.

 

[HelmutSheina]

The cowling splits, getting to the shaft and shift mechanism is easy. I don't think its the detent either but the OP said he wasn't sure what it was when he was contemplating dismantling it.

While it will take a little bit of time to strip it down, none of it is difficult or hard to access and is fairly logical.

Thanks for the cowling info, the split bottom lids have saved a lot of work. I wasn't criticisong re shaft, just pointing it out as tbe likely culprit.

 

[fallguy]

I’m gonna go with gunk in the lower unit, up to an including a rebuild.

After you isolate the issue; if you find it to be in the gearcase; it is getting warm down there, if not for gunk in the pump impeller passages, then for wear.

hope I am wrong; good luck

 

[HelmutSheina]

Gunk in the cooling passages won't seize the gearshift, but it will seize the engine.

 

[Russell Brown]

Found a diagram, the horizontal shaft is a likely candidate, also the detent system on the stbd side of the diagram, may be corroded or dry and binding.

View attachment 208441

Well, I finally got to it and had some success. I was able to move the right-hand (looking aft) part of this assembly outboard a bit and now it seems to work, though still stiff. I had to pry and wiggle a lot to get any movement after removing the #19 bolt. I didn't take the whole thing apart because I needed the boat today and didn't want to break anything. The part (#2) looks like Nylon, so maybe swollen onto the shaft.
The middle part of that assembly isn't visible without going down a layer or two, but I don't suspect that for the stiffness. I don't suspect the ball either because it's getting into neutral that's the problem.

 

[HelmutSheina]

I don't have experience of these models, so will be winging it a bit. Also the below novel assumes the shaft #4 is where the binding is. Did you mean the #18 bolt? Leave that on for now as #17 is the one that releases the shaft if it can be accessed.

The plastic bit on the side is a detent mechanism with a spring loaded ball that sits in 3 detents for F-N-R location, it provides the "click" in basic terms. If the whole lever assembly will come off in one bit it would be good as steel balls are so easy to lose. Plastic on stainless should not be seized, but who knows?

I took the liberty of visiting another diagram, which may not be the exact year/model, but hopefully close enough for this. See below.

The blue scrawls I drew point to two holes in the lower engine block through which the shift shaft passes, and I would imagine, though cannot see, that each side would have a nylon bushing. These bushings are often compressed by aluminium salts growing between the alloy and the plastic.

Now you could squirt some oily crap in there and work the shaft until it frees, but you'll be back at it in three months, with associated downtime etc, do it that way though if there is urgency, and do it properly later.

That #4 shaft needs to come out, clean it all up, replace parts as necessary, regrease & reassemble. Any automotive lithium wheel bearing grease is marine grade - without the tax.

Digressing a bee's apparatus, same goes for 80W-90 EP mineral gear oil and 75W-90 synthetic gear oil, automotive works at often half the price, and factory talk of emulsifiers in their brands is BS to justify the "marine" tax.

Firstly you need to ascertain whether the #4 shaft will slide out from under the powerhead with the lower cowling intact, and if not split the cowling open by undoing the 4 or so screws.

If you consider the previous diagram of the shift lever and shaft:
We need to remove the stainless linkage 6, and perhaps 5. Then there is a screw 17 with a washer under it that screws into the shaft at 90°, and it appears the detent stuff doesn't have to come apart to get the shaft out. Once 17 is removed the lever 7 should slide off the shaft.

You might then want to disconnect the shift shaft 5, and take the detent stuff to a bench to clean & regrease.

Put it all back together.

Test with BEER!