Checking the engine oil strainer / screen

[NY_Fred]

Hey folks,
In preparation for buying my first ST, I'd like to be able to have a look in the engine oil strainer to see if there is any chrome bits indicating flaking rockers. This is a little confusing for me, since my knowledge of cars to not seem to apply - there is a filter that should remove any bits/chemicals in the oil, so what does the screen do??

From what I understand the screen is threaded into the block behind the 'sump plug.' Do they mean the sump fill plug, or the drain plug? Since they say I'll need an allen wrench I'm guessing they mean the sump drain plug under the bike?? I undo the sump plug with a 14mm allen, and then I'll see the screen threaded into the block behind the plug cap, which I also remove with a 14mm allen. However, other sources, including a youtube DIY-oil-change video say 10mm to remove the sump drain plug.

I have a few questions,

1) I'm confused about which 'sump plug' they are talking about to gain access to the screeen. Does anyone have a picture of the sump plug so I can quickly locate it?

2) Which size allen do I need to get to the screen?

3) I thought that if I remove the sump plug I'm going to start draining oil out of the sump. How much oil will I need to replace what's in the engine once it all drains out? 3 quarts, run the bike, add 1 more quart?

4) The owner says the oil was changed in the fall, so would you think it bad form to just catch what drains in a clean container and pour it back in afterwards? Speaking of pouring it back, where do I pour it back into?

5) Do I need to remove any of the fairing to get to the sump drain plug? I'd hate to make a mess all over this guy's bike.

[bbagdan]

1. The sump plug is on the lower front right SIDE of the crankcase, and is easily identified by the 14mm allen recess. The oil drain plug is on the bottom of the crankcase.

2. You need a 14mm allen wrench to access the screen. This wrench is included in the bike's tool kit. You need to drain the oil out of the engine through the drain plug first, however. You will also need to use new crush washers when reinstalling both plugs (and be careful not to overtorque).

3/4. If the oil is new-ish, just repour it back into the engine through a fine filter. The oil fill cap is black plastic, also located on the right side of the crankcase.

5. You need to remove the lower right fairing panel to do oil changes.

[NY_Fred]

Thanks for the reply. Let me see if I understand this...

I will need to remove the lower right fairing (hopefully only the lower right fairing panel, and being careful not to strip the wellnuts) to access the oil drain plug on the bottom side of the crank case. This could be either a 10mm or 14mm allen plug, but is probably in the toolkit under the seat.

I then need to open the oil drain plug and catch about 4 quarts of oil.

Then I open the sump plug on the side of the crank case with a 14mm allen wrench. Behind the plug cap is the screen, threaded into the block. It's purpose is still unclear but I guess it filters LARGE things out of the engine oil before they get to the engine oil filter?? It also is removed with a 14mm allen. I can then check for chrome bits on the screen as a possible means of checking for flaking rockers.

Replace crush washers - if you're anal about that sort of thing. Reinstall screen and plugs. Replace oil or pour old oil back in, optionally through a fine filter that I carry with me. Reinstall fairing. Use the information gleaned to either a) ease my mind that the rockers have not (yet) started to flake, or b) set about negotiating the value of the seller's asking price, and hope that Ducati will replace any flaking rockers on low-mile early ST4 engines even though they are out of warranty.

[bbagdan]

sounds about right. regardless of what the allen size is for the particular model year of oil plug, they should be in the tool kit.

the filter screen is probably a tool to help diagnose engine wear, because otherwise you'd have to take apart the oil filter, which is a messy proposition.

i think it's only recommended to check the filter screen every 20kkm/12k miles.

If you're going to use new oil, fill with 3 quarts first. then add the last .5 quarts very slowly in several increments, letting the oil settle for a good half hour before adding a little more. fill oil to halfway between the marks.

[Jeff_Tippett]

Fred,

I agree with all of the above. If you don't replace the crush washers you may over tighten the drain plug to stop a drip. You stand a chance of stripping the threads on the (brass) plug. Don't ask me how I know.

If the seller drained the oil last fall. he may have removed any evidence of chrome flakes from the screen. The only real way to know if you have problem rockers is to remove them. This is a major job involving removing the cams etc. Forget about Ducati replacing the rockers on goodwill. They did this for a few years but from what I have heard they have discontinued this practice.

Does the seller have service records? Have the valves and belts been checked (belts replaced) per the maintenance schedule? If not, don't pay anything like book value. If you really want this bike, try to arrange a "holdback" of several hundred dollars pending having a dealer check and adjust the valves at your expense (a good idea anyway). In order to change shims the rockers have to come off and they can be checked then. If you have some bad rockers (@ $100 per) the seller should pay some or all of that expense.

There are lots of good, used STs out there with complete maintenance records. You may want to keep looking. The '02 and later 4s are better bikes IMO.

Jeff in Colorado

[jerry5]

This really is not going to show you what you are looking for. There will definately be metal shavings on the screen that will make you assume that the rockers are flaking. The shavings will likely be from another source. The "ONLY" true way to check for flaked rockers are to remove the cams and inspect the rockers. If you want the bike take a chance and buy it . If you can't get past the risk, negotiate a deal where after purchase you have the bike serviced and if any flawed rockers turn up that the seller replaces them. Draining oil and pulling the screen from a sellers bike is just a bad fishing trip. If a buyer asked to do that to one of my bikes I would politely ask him to leave.

Jerry
04 ST4s (with 42000km and no flaked rockers)

[jssport]

What years/motors had flaking rockers?

[ST4R]

You can search this forum for "flaking rockers" where you should find many discussions.

Ducati used to replace failing rocker arms on a "good will" basis however that practice is now uncommon. And to add insult to injury - Ducati have recently raised the price of new rockers to over $200 each, and the replacement rockers are just as likely to flake!

I believe the problem first appeared on model year 1999 4V engines. My 2001 had three replaced under warranty back in 2004, and then recently when 5 more appeared I replaced all 16 with Megacycle rockers to put an end to it.

If you pull the strainer and see flakes of chrome - it's rather late in the game. Each time you adjust the valves you need to pull the cams (adds half an hour labor) and take a good look at each rocker. That's really the only way to see the black patch on the chrome indicating the beginning of the end of that rocker.

As someone else stated: if the owner has good maintenance records, you're fine. If not, you may be looking at an expensive repair. The only way to know for certain is to pull the cams and have a look.

Megacycle rockers are $89 each however they put an end to flaking rockers forever because there is no longer any chrome on the Megacycle rockers. There are other good companies out there who replate rockers for closer to $50 each.

It's a shame to have to spend that kind of money on defective stock Ducati parts, but the ST4 and ST4S are great bikes and in my opinion real keepers.

[SS904]

As has been said, finding chrome flakes in your screen is about the same as the oil light coming on in your car... Too late.

This rocker thing is a bit over rated IMHO. Like many things, people who have had this problem will make a bunch of noise. The many that have not had a problem just quietly go on with life and enjoy their bike. Not saying it isn’t a problem, it certainly is, and I personally don't appreciate the way Ducati has decided to handle it. If I find a bad rocker again, it will be replaced with something other than the $200.00 Duc part that could fail again. Right or wrong, it’s part of ownership with the 4V pre-Testa Ducs.

For the record, I did replace two rockers @ 6K on my 03 ST4S. They had dark spots in the chrome but no flaking yet. I do my own adjustments. It is really very simple to pull the cams. This, by the way, is the ONLY way you can see the part of the rockers that you need to see.

Regarding you pulling the screen on that seller’s bike. If it was me selling and you insisted, I would ask you to keep looking. I may agree to have the bike checked by the dealer at your expense if it was that big of a concern. I have all the bike’s service records to show. IMO, when buying a used bike that should be good enough. You may find something in the screen. It will likely be bits from the transmission rather than chrome flakes from the rockers. I have found a chunk or two in the time I have been a Duc owner (2001), but it is fairly normal. If he has maintenance records, you should be good. Better yet, if he has had the work done at the dealer, ask them about the bike's history.

If the seller lets you go through with this, some notes on tools. The tools (at least in the two Ducs I have owned) are not in the bike's kit. Please don't pop in here and say "the other side of the plug wrench is a 14MM allen". It is, but I wouldn't use it on my bike! You will need a 10MM allen wrench for the drain and a 14MM allen for the sump screen. The cap to the sump screen on the water cooled bikes will also be a 14MM allen.

The "crush washers" aren't... They are just soft aluminum washers. They can be reused as long as they are not bent or nicked. They are very inexpensive from the dealer, and it's better to replace if you have them.

The sump screen filters job in a Duc is the same as the sump screen in a car. Catch the big chunks before they get to the finer grade oil filter and smaller oil passages. The difference here is you can easily pull it to clean and inspect it.

[NY_Fred]

Hey guys,
wow, thanks for all the replies. I got the impression from the procedure that it was a fool's errand, maybe even a nightmare, and could cause a bad vibe for the seller. I agree with all of you that if you were trying to sell a bike, and someone started pulling off fairings to do an oil change to look for metal, I'd be a little concerned at best, and at worst I'd suggest they leave.

And as pointed out, even if Ducati did replace the rockers, the new ones would be just as likely to flake. The only solution that most members have found is to go with aftermarket rockers and be done with it. They're cheaper than OEM, and last longer too.

FYI - the bike is a 99 ST4 with ~9500 miles. It hasn't had it's first 12000 mile service interval yet, so I'm not sure there are even that many records to have. The seller is the second owner and has told me he does some work on the bike himself - oil changes, and a fuel filter replacement. I'm not sure if he's been replacing belts every 2 years, but I hope so. Asking him why he's selling it, he told me he has a 20 year old that wants to learn to ride, and needs to sell a bike to get a good learning bike for his son. He told me he has another bike already, so I guess he doesn't/didn't use the Duc that much. On one hand, the low mileage might mean that the flaking rocker problem hasn't yet manifested itself. On the other, I'll wonder what I will do if I check the rockers at 12K miles and see a problem.

Some people have suggested many, shall I call them 'conditional', sales agreements- such as the seller pays half the 12K service, a hold-back of some money until after the service and the bike checks out, and a potential discount given after the service interval if any problems come up. The problem with all these things is that as a seller, especially a second owner, you want to sell the bike and not have to hear about it down the road - especially 2000 miles down the road that weren't your miles. If the bike had 20 or 30 or even 40 thousand miles, I would say this was a good idea. But with 9500 miles, I feel awkward trying to ask the seller to basically warranty the bike free of defects for the next 2000 miles until the first 12K service.

As for the crush washer, having worked on cars long enough I understand their purpose. They are soft metal, usually copper, that seat the bolt against the block. So long as they aren't nicked/chipped/scratched/gouged/bent I reuse them a couple of times. I've never had problems, but YMMV.

As for which bikes have flaking rockers - the early ST4 models did, I think in 2001 people were still reporting problems, but in 2003 I think it stopped.