Rocker wear

10-03-2005, 09:20 PM

Does it affect 2 valve motors or is it endemic to the 8 valvers I need to know as this may well affect my next choice of bike

Pedro · 10-03-2005, 10:00 PM

From what I understad Nigel, it's more of a prob on the 4 valve heads rather than the two valve units.

Can we assume you may have some dodgy chrome coming off?

Ped

10-03-2005, 10:29 PM

My understanding is that the premature rocker wear problem that was due to poor plating affected early 916 motors and has not affected S4s.

Zimbo · 11-03-2005, 06:44 AM

It only affects 8 valve non stretta engines. It's caused by insufficient oil feed to the rockers, and will affect all 748, 916, 996 engines, although it's not necessarily as bad as is sometimes reported, a friend with a 748 has just had his first rocker replaced at 36,000 miles. Depends how you ride i think, if you use high revs a lot then they're more likely to go on you.
The Stretta engines (998, 999) have the crankshafts running in journals rather than standard bearings, which require a much better oil feed, so they have a better flow of oil to the rockers, and consequently don't suffer from this problem.
The 2 - valve engines don't suffer the problem either - possibly because they rev much less???

CK & AK · 11-03-2005, 07:52 AM

umm, we (sorry, Alan) have just had to replace the rockers in a 2001 M600 (18 thou miles) as were flaking. Reshimmed too now.
Only got picked up, as engine totally stripped for checking prior to racing. If we had just been 'tidying' her for a swift re-esale, then we wouldnt have spotted this.

How many people actually inspect these anyway, and if they are breaking down it is not picked up till far too late.

Has happened in a few monsters, but not a common problem as Zimbo says - but it can occur.

Alans view is that the 4 valvers are possibly used much more to the limits & this could asist with the extreme wear - as you say Zimbo

11-03-2005, 08:13 AM

I have just hit 45,000 miles on a 900 2 valver. Wear is negligible with just one shim needed in all that time.

I suspect the problem afflicts bikes not ridden often where the oil takes time to get on wearing surfaces and bikes using crap oil or not serviced regularly.

A lot of 4 valvers have very low mileages and are kept as toys, dont get ridden for long spells etc. These seem to suffer more than their fair share of mechanicals. Ducatis ridden often are usually very reliable.

CK & AK · 11-03-2005, 12:19 PM

Quote from my fave Ducati mech (he's lovely!

)

"The 2V rockers are far more robust. As with everything they will wear out eventually, but nothing like as quick as the 4V.
Oil feed is better and the chroming seems to be of better quality.

Main problem with 2V rockers, that causes them to wear abnormally is valve clearances. Spec's are tight and if they are done too tight the rocker gets a hammering."

Al reckons his ones were stuffed, as there had been no servicing to speak of to the bike

C

11-03-2005, 12:54 PM

I think with the four valve motors you either get a good one or a bad one. My ST4 needed three rockers at 18,000 miles while my mates 996 needed a grand total of 13 and it had only done 7000 miles. For anyone who thinks it isnt a common problem then i suggest you pop into Cornerspeed where Neil will show you a plastic bag full of all the failed rockers he has swapped in the last year or so. Must be about 60 of them.

11-03-2005, 01:36 PM

No problems with my S4 so far but examples can be found in you look at the various forums, as i understand the problem was supposed to have been fixed in 2001 with rockers that are identified by having punch marks on the side of them.
The 2 valve motor seems more robust and maybe a safer bet if you can do without the extra BHP from the 4 valver.

There are many problems listed with the 4 valve motors and it probably would have put me off buying one if i knew then what I know now albeit I have had no problems and it is a top engine, far more rewarding than the Japanese equivalent.

11-03-2005, 02:16 PM

Quote:

Originally Posted by CK & AK

Quote from my fave Ducati mech (he's lovely!

)

Main problem with 2V rockers, that causes them to wear abnormally is valve clearances. Spec's are tight and if they are done too tight the rocker gets a hammering."

C

Might this be the cause of the 'rattly' noise I can now hear from my engine since having my valve clearances re-shimmed (they had been way out and running like that for a while)? if so is it potentially fatal to the engine or will it just run noisily from now on? If it's the latter then it's not a problem I'll just refit the loud pipes!

CK & AK · 11-03-2005, 02:44 PM

Nick - its when its NOT noisy, you need to worry!

As you have had shims done there shouldnt be a prob....

11-03-2005, 02:46 PM

as the lady sayeth they all do that, although like me you have the old forged or cast pistons (I forget which) that make the school bell noise a bit on start up.

11-03-2005, 02:48 PM

Cheers guys, that feck (for want of a stronger expletive) for that!

11-03-2005, 05:41 PM

Thanks for the replys

i'm booking the bike in in the next couple of months I was warned by my mechanic (at the 12000ml service) that it may need new rockers at the next service, of course there is no way of being sure until he takes the heads apart, maybe he was just being cautious but he knows his stuff so i don't question his decisions

11-03-2005, 07:45 PM

I think ducati have changed the part number of the 4 valve rockers something like 17 times since they realised there was a problem so the story about a bad batch of chroming is rubbish! Its bad design, simple as that. Spot on adjustment and good oil is about all you can do. I have however heard of a mod to the oil feed to the heads which might help things.

10-03-2005, 09:20 PM	#1
Nigel C Guest Posts: n/a	Rocker wear Does it affect 2 valve motors or is it endemic to the 8 valvers I need to know as this may well affect my next choice of bike

10-03-2005, 10:00 PM	#2
Pedro Ciao, come stai? Join Date: Apr 2003 Location: Somewhere Bike: Multiple Monsters Posts: 4,157	From what I understad Nigel, it's more of a prob on the 4 valve heads rather than the two valve units. Can we assume you may have some dodgy chrome coming off? Ped __________________ M900 - 1993! Monster 1200R!

10-03-2005, 10:29 PM	#3
PaulS Guest Posts: n/a	My understanding is that the premature rocker wear problem that was due to poor plating affected early 916 motors and has not affected S4s.

11-03-2005, 06:44 AM	#4
Zimbo Too much time on my hands member Join Date: Apr 2003 Location: Stonehouse, Glos Bike: Multiple Monsters Posts: 2,079	It only affects 8 valve non stretta engines. It's caused by insufficient oil feed to the rockers, and will affect all 748, 916, 996 engines, although it's not necessarily as bad as is sometimes reported, a friend with a 748 has just had his first rocker replaced at 36,000 miles. Depends how you ride i think, if you use high revs a lot then they're more likely to go on you. The Stretta engines (998, 999) have the crankshafts running in journals rather than standard bearings, which require a much better oil feed, so they have a better flow of oil to the rockers, and consequently don't suffer from this problem. The 2 - valve engines don't suffer the problem either - possibly because they rev much less???

11-03-2005, 07:52 AM	#5
CK & AK flob-a-lob-a-lob Join Date: Aug 2002 Location: NW Surrey Bike: Multiple Monsters Posts: 3,306	umm, we (sorry, Alan) have just had to replace the rockers in a 2001 M600 (18 thou miles) as were flaking. Reshimmed too now. Only got picked up, as engine totally stripped for checking prior to racing. If we had just been 'tidying' her for a swift re-esale, then we wouldnt have spotted this. How many people actually inspect these anyway, and if they are breaking down it is not picked up till far too late. Has happened in a few monsters, but not a common problem as Zimbo says - but it can occur. Alans view is that the 4 valvers are possibly used much more to the limits & this could asist with the extreme wear - as you say Zimbo

11-03-2005, 08:13 AM	#6
Duncan Guest Posts: n/a	I have just hit 45,000 miles on a 900 2 valver. Wear is negligible with just one shim needed in all that time. I suspect the problem afflicts bikes not ridden often where the oil takes time to get on wearing surfaces and bikes using crap oil or not serviced regularly. A lot of 4 valvers have very low mileages and are kept as toys, dont get ridden for long spells etc. These seem to suffer more than their fair share of mechanicals. Ducatis ridden often are usually very reliable.

11-03-2005, 12:19 PM	#7
CK & AK flob-a-lob-a-lob Join Date: Aug 2002 Location: NW Surrey Bike: Multiple Monsters Posts: 3,306	Quote from my fave Ducati mech (he's lovely! ) "The 2V rockers are far more robust. As with everything they will wear out eventually, but nothing like as quick as the 4V. Oil feed is better and the chroming seems to be of better quality. Main problem with 2V rockers, that causes them to wear abnormally is valve clearances. Spec's are tight and if they are done too tight the rocker gets a hammering." Al reckons his ones were stuffed, as there had been no servicing to speak of to the bike C

11-03-2005, 12:54 PM	#8
Rockhopper Guest Posts: n/a	I think with the four valve motors you either get a good one or a bad one. My ST4 needed three rockers at 18,000 miles while my mates 996 needed a grand total of 13 and it had only done 7000 miles. For anyone who thinks it isnt a common problem then i suggest you pop into Cornerspeed where Neil will show you a plastic bag full of all the failed rockers he has swapped in the last year or so. Must be about 60 of them.

11-03-2005, 01:36 PM	#9
Shauns4 Guest Posts: n/a	No problems with my S4 so far but examples can be found in you look at the various forums, as i understand the problem was supposed to have been fixed in 2001 with rockers that are identified by having punch marks on the side of them. The 2 valve motor seems more robust and maybe a safer bet if you can do without the extra BHP from the 4 valver. There are many problems listed with the 4 valve motors and it probably would have put me off buying one if i knew then what I know now albeit I have had no problems and it is a top engine, far more rewarding than the Japanese equivalent.

11-03-2005, 02:44 PM	#11
CK & AK flob-a-lob-a-lob Join Date: Aug 2002 Location: NW Surrey Bike: Multiple Monsters Posts: 3,306	Nick - its when its NOT noisy, you need to worry! As you have had shims done there shouldnt be a prob....

11-03-2005, 02:46 PM	#12
A Yerbury Guest Posts: n/a	as the lady sayeth they all do that, although like me you have the old forged or cast pistons (I forget which) that make the school bell noise a bit on start up.

11-03-2005, 02:48 PM	#13
nik_the_brief Guest Posts: n/a	Cheers guys, that feck (for want of a stronger expletive) for that!

11-03-2005, 05:41 PM	#14
Nigel C Guest Posts: n/a	Thanks for the replys i'm booking the bike in in the next couple of months I was warned by my mechanic (at the 12000ml service) that it may need new rockers at the next service, of course there is no way of being sure until he takes the heads apart, maybe he was just being cautious but he knows his stuff so i don't question his decisions

11-03-2005, 07:45 PM	#15
Rockhopper Guest Posts: n/a	I think ducati have changed the part number of the 4 valve rockers something like 17 times since they realised there was a problem so the story about a bad batch of chroming is rubbish! Its bad design, simple as that. Spot on adjustment and good oil is about all you can do. I have however heard of a mod to the oil feed to the heads which might help things.