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  #11  
Old 08-Jun-2003, 20:21
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DSC Member Shazaam! Shazaam! is offline
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pj748r, despite Nigel C's attempt to suck me into an oil thread, you can rest assured that your problem was not caused by the lack of an oil additive.

On bikes with 4-valve heads, the rocker arms have simply not been reliable. A good number of them flake-off their chrome plating before the time of their first service at 6,000 miles and that often can result in scratched camshaft lobes if not caught in time. The rocker arms in 851/888's and pre-1996 916's typically lasted 80K miles with no problems. 1996 was the year when Ducati began to outsource the rocker plating to subcontractors and problems began.

Ducati basically concedes that there has indeed been a rocker problem in the past, but has repeatedly assured us that things have been fixed. They also point out that the rocker problem will be covered under warranty, even if you're outside the warranty period, (if it's not a race bike or an SPS/R.) So, when you have this problem, just work with your local dealer who will replace the damaged parts. If you're out of warranty, you usually will have to pay for the labor cost only.

They're not just being good guys here. From a legal standpoint, if there is a known manufacturing defect, warranty period or not, the manufacturer is responsible to sell you goods that can perform up to the standard expected when purchased - no matter how long after purchase.

There probably have been 17 rocker design iterations over the years. For 2001, Ducati announced they were now using an improved rocker design that is also compatible with earlier year engines. The new 2001 opening rockers can be identified by a small dot punched on the side where they fit onto the shaft. Unfortunately these rockers fail in exactly the same way. So even if you have a 2001 or later model, make sure that when you have your bike serviced at 6K miles, that they remove the cams (25 minutes labor) and inspect the rockers since any damage cannot be seen otherwise. The flaking starts as small little patches and if you catch early you can avoid cam damage.

To play it safe, and to make sure that Ducati doesn't balk at replacing your rockers, it's a good idea to keep adequate records to show that you've adjusting the engine valve clearances to Ducati specs on schedule, and used a lubricant that conforms to Ducati's specification in the owners manual.*There have been instances reported where some Ducati dealers have tried to make the owner feel that they have somehow abused the bike and then charged them for repairs.

The rocker arms have a hard chrome coating to increase their wear resistance where they contact the cam lobe. The opening rockers are more likely to be affected but occasionally the closing rockers flake as well. The closers don't take anywhere near the abuse as the openers.

There has been a lot of debate about the reasons why the chrome comes off. The answer is likely a combination of inadequate chrome thickness and the unusually long time needed for the oil to reach these parts during a cold start. In normal circumstances, a good synthetic oil would leave a surface film that is adequate lubrication until oil flow is established.

There's correlation between a lack of oil and rocker failures. For example, the horizontal cylinder exhaust rockers sit in a oil bath and rarely fail. Most often, failures are seen in the more distant vertical cylinder rockers, especially on the hotter exhaust side. For the 1999 model year, Ducati increased the size of the oil galleys to the heads to try to solve the problem.

I don't think Ducati knows the definitive answer. If they did, the problem would’ve been corrected years ago. If it's any consolation, this type of problem is not unique to Ducati. Other manufacturers have had rocker hard coating issues in the past. Honda, Kawasaki and Suzuki, to name a few.

Replacing a failed rocker with another having the same potential for failure doesn't make a lot of sense, so some owners have installed Megacycle rockers, stock rocker arms that have been machined down in thickness to allow for a greater thickness of chrome to be applied. Others say that the Corsa rockers are the ultimate fix.

The Megacycle fix is to grind the rocker/cam contact area back .035 to .040 inches and then build back up with a hard nickle-chrome boron alloy brazed onto the rocker, then grind the repair back to factory specs.

http://www.megacyclecams.com/

See Neil Spalding's articles on the Signa Performance website for more information:

http://www.sigmaperformance.com/rockers.html
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  #12  
Old 08-Jun-2003, 21:08
Henners Henners is offline
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998 Testastretta

What's the situation with the testastretta engine Shazaam?

[Edited on 8-6-2003 by Henners]
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  #13  
Old 08-Jun-2003, 21:10
pj748r pj748r is offline
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thanks for all the advice fellas.I have emailed Ducati Uk but haven't had a reply yet!I have got to ring Dealers tomorrow to see how they are getting on with it,might chase up DUK thru them especially as it seems to have been a common problem having looked back thru the old message board.Think previous owner mightn't have been very mechanically sympathetic!Might change oil+filter every 3k to be on safe side.Any recommendations on oil Motul/Shell?mobil 1.Have used Mobil1 on all previous Jap bikes R6,ZX6r etc allhigh revvers compared to Dukes.Still no matter the outcome won't be going back to UJM.
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  #14  
Old 08-Jun-2003, 21:26
Felix Felix is offline
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Shazaam, I can tell you from my own experience that Corsa rockers also flake. I usually have to replace at least one rocker at every valve shimming, which is about 500-1000 miles. This is on a factory RS engine running Motul 300V, which some people claim is the best oil for protecting against failures due to the long time before oil reaches the heads. My feeling is that any top spec racing oil is about equal in protecting against this. I agree with you that the rockers are just not up to the job. Haven't tried to get them replated by others such as Megacycle (I've even seen Megacycled rockers flake). Just consider it a consumable which in most cases (not mine unfortunately) Ducati supply at no charge.
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  #15  
Old 09-Jun-2003, 01:13
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DSC Member Shazaam! Shazaam! is offline
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Henners, the new testatretta engines with their plain bearing cams have significantly shorter oil lines, coming up the right hand side of the engine.*Hopefully, a reduction from the 90 second-or-so lubrication delay encountered with the earlier engines will help to solve the problem.
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  #16  
Old 04-Aug-2003, 22:04
pj748r pj748r is offline
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Finally got bike back on saturday afternoon.DUK paid for the camshaft and half the cost of the 3 rockers.Didn't charge for labour.Ride home convinced me why I got rid of my R6!Any one had any probs with DPchip as I had it fitted at service,it cuts out sometimes when idling at lights(standard chip didn't).Apart from that no flatspots above 3k and it picks up great.
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  #17  
Old 04-Aug-2003, 22:20
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DSC Member Guido Guido is offline
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Bikes: '01 Ducati 748R and '04 Mille RSVR
 
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Mood: Awaiting the arrival of the sun and the disappearance of the rain
PJ,

My 748R used to cut out at lights etc on the DP chip (with 45mm termi's). My dealer swapped it for a JHP item and it's been much better. The dealer tweaked the TPS (Throttle Postion Sensor) and idle adjustment too.

Runs like a dream now (even at traffic lights or slowing for them). Hasn't cut out on me in months.

On a final note....Hit 18k miles tonight on my blast out b4 a week away at the office.

Sun was blazing, heat was hot...Isn't life ace.!!!!!

On an even more final note.... If your bike still plays up, go and see Nelly at Cornerspeed (just off M1 Jnctn 28). He'll sort if for you

[Edited on 4-8-2003 by Guido]
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