sludge in classic 4C MVs -
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 06-30-2016, 03:45 AM Thread Starter
Senior Member
emmevi125s's Avatar
Join Date: Sep 2006
Location: Melbourne, Australia
Posts: 1,762
sludge in classic 4C MVs

I just came across this which some members will have seen but for the others it's worth considering.

OK MV nuts, I did another motor teardown this weekend and pulled a lot of
crap out of a Sport crank. I see this all the time, sludge and debris in the
crank cheeks filling up the groove. As usual the culprit is the damn weak
magnet in the drain plug. The owner was here to witness, as we dove into the
motor taking it apart and assessing what it needed for rebuild. He was
shocked to see the crap I was digging out. The material was all magnetic and
if his magnet was working it wouldn't have been so polluted. So here is a
little advice. On your next oil change, take out the crappy MV installed
magnet and install a neodymium magnet and most of the trouble will be gone.
Plus, you will see a much bigger collection of crap on the new magnet when
you change your oil the next time. Double goes for the singles and twins
that don't have the magnet. If you don't feel comfortable doing the magnet
swap, let me know, I can do it, or epoxy some into your sump. - Albert

A good source of those magnets is old computer disk drives.
emmevi125s is offline  
Sponsored Links
post #2 of 6 (permalink) Old 06-30-2016, 04:41 AM
Senior Member
adrian's Avatar
Join Date: Apr 2006
Location: Brighton, Melbourne
Posts: 1,299
Exactly what we found in the Felotti and spoke to Albert about this and he said its common with the twins because of the crap oil filtration and was coming up with something for owners.
News to me about the 750s , time for that oil change was planning on doing it now anyway. cheers

1946 Mv Agusta "98"
1955 Mv Agusta 175cs
1960 Mv Agusta Rapido sport 150
1974 Mv Agusta 750 sport
1977 Mv Agusta 350 Felotti
2004 Mv Agusta F4 SR
2005 Mv Agusta Tamburini
2001 Ducati Mh900e Carbon dream
2004 Ducati 998R
2015 Vyrus 987
adrian is offline  
post #3 of 6 (permalink) Old 07-03-2016, 01:05 PM
New Member
Join Date: Aug 2010
Posts: 34
I would like to know how often the oil and filter was changed on these engines before getting too excited
valspar is offline  
Sponsored Links
post #4 of 6 (permalink) Old 07-04-2016, 02:19 AM Thread Starter
Senior Member
emmevi125s's Avatar
Join Date: Sep 2006
Location: Melbourne, Australia
Posts: 1,762
The original post was from Albert Bold who has been working on classic 4C MVs for 20+ years.
emmevi125s is offline  
post #5 of 6 (permalink) Old 08-03-2016, 11:57 AM
New Member
Join Date: Apr 2011
Location: aptos,california, usa
Posts: 4
sludge...quite unbelievable..!!

That was my bike that Albert Bold was talking about. I was there and helped in the disassembly of the motor. I've owned the bike 33 years and the oil is changed often , the bike has shy of 28k km, out for a thrashing once a month at least. Decided to tear down the motor after a bevel gear box failure @ the driveshaft, as it shares the same oil as the engine . It looks like we caught it in time, as it appears there was no damage to the bearings . The crank has some ridges on the sides that throws oil into the rod big end journals which are hollow and lets oil flow to the rod. the amount of stuff, kinda like hard dirt, that came out of those you would not believe. He flushed it with a parts cleaner and used wire tools,etc. to get in those areas and dig it out .metallic dirt..!! The split roller mains were perfect, pistons looked new , bores worn about .001. I did not want to tear into the motor , it runs so good, yet I don't think you can afford not to in my case. Albert's seen rod failure on these beyond 20-25k mi due to oil starvation @ the rod. Oh, and he's got about 40 yrs with MVs.. Lee
Mr. Lee is offline  
post #6 of 6 (permalink) Old 08-03-2016, 01:07 PM
New Member
Join Date: Aug 2010
Posts: 34
Thanks Mr Lee
Can you tell me what oil was used and if the filter was changed at the same time.
Also are you aware of later filters not sealing properly allowing unfiltered oil to pass unless modified
valspar is offline  

Quick Reply

Register Now

In order to use all of the features of the site, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome