Ducati Monster Motorcycle Forum banner

1 - 19 of 19 Posts

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter · #1 ·
I'm a few hundred miles from checking the valves for the first time since I adjusted them. If any are out of spec I'm planning to throw in some MBP collets while at it.

I'm curious as to whether switching to MBPs will guarantee I have to adjust all the closers, or if they end up real close to the stock wire collets (assuming they are in spec at the time)?

I've heard conflicting reports on this. Anyone have firsthand experience with this swap? Just trying to figure out if I need to save enough beer money over the next week or so to cover a pocket full of closing shims. LOL

TIA,
Mark J
 

·
Registered
Joined
·
45,105 Posts
if you change collets, MBP or otherwise, valve clearane check is needed. the collets do take some pounding plus there is probably a manufacturing tolerance issue.
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter · #4 ·
Yeah, I'm aware of the many issues affecting clearance. I could tell a difference with my stock wire collets if I put them in upside down from their original position.

What I'm interested in is personal experience as to how much if any MBP collets differed from the wire collets that came out of a specific bike. I've heard reports ranging from no difference to prepare to adjust all closers.

I definitely don't bolt anything back together without triple checking clearances. That way I have peace of mind for at least 2,999 miles

Mark J
 
G

·
this past spring installed mbp collets 99 750,2500mi. i noticed no difference in closer tollerances. maybe the stock collets didn't have any wear yet.
if you have more miles on yours. you might want a selection of shims on hand.
the mbp collet might tighten the gap.
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter · #6 ·
Thanks! This valve check is at 15,000 miles. The stock collets don't look too hammered, so I may get lucky and only have minimal changes to adjust for.

Mark J
 

·
Premium Member
Joined
·
3,677 Posts
i think mbp collets are overkill for street bikes. once you race or have aftermarket stianless steel valves, then they become more necessary. installing the collets makes performing valve adjustment quite a chore. stick with OEM collets, adjusting the shims as the wire collets work harden. do not flip the collets. then after 12,000 or 15,000 miles, they shouldn't need adjustment. :)
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter · #8 ·
Chris,

How do the MBP collets make adjusting more of a chore?

I got to handle some MBP collets at a seminar held by Guy Martin in Daytona (DOL Ducati Party). They seem to be a lot easier for me to handle than the slippery little SOBs from the factory. I specifically tried placing them in position and found them easier to keep under control.

The stockers give me fits trying to keep them oriented the right way (close-up eyesight or lack thereof compounds the problem). Every pair of hemostats and needlenose I have - and that's a bunch- tend to shoot the wires through the rocker space just when I think they are going to lay into the groove.

So it's as much a dexterity issue for me as a performance thing. But I'm interested in any negatives you know of that add to the chore of adjustments.

Thanks,
Mark J
 
G

·
i'm betting the chore is having to do valve checks and possible reshimming of each and every one of your valve's opener and closer shims after replacing the stock collets with the mbp collets.

i'll ditto chris's sentiments... and that of bcm bruce's sentiments... the stock half rings work harden after use... i've found little to no adjustment needed after the first two services. i'll be coming up on the 24k service soon to be able to verify.

a dab of grease on the valve stem has always kept the collets in place for me... once i place 'em they stay put.

mbp definitely has an application for bikes at high rpms or possibly using softer valves (stainless or titanium) but aren't neccessary for street bikes imo. most of the failures seen were on 748's (highest revving ducati motor) that were racing (seeing continuously high rpms). keep in mind also the four valver stem is significantly smaller in diameter than the two valver.

of all the "reliability" concerns this would be pretty low on my totem pole unless i raced a 748. i know the collets are real pretty but i like the simplicity of the ducati keepers.
 

·
Premium Member
Joined
·
3,677 Posts
the way that MBP collet works is by forming a solid joint of the shim/collet/valve junction. this is performed when you hammer the valve and collets down into the closing shim, using the closing rocker arm as an anvil.

ok now. they're hammered together. but you made the adjustment too tight or too loose and now you have to take it apart. so you've got the forceps on the valve, you're holding down the closing rocker arm while simultaneously holding a small punch and then you strike the punch with a ball peen hammer to knock the closing shim down off of the mbp collets and the valve. only, instead of the closing shim coming loose, the punch slips off the closing shim. or you "drop" the closing rocker arm "up" and it smacks the closing shim ON to the valve and collet. better still, you slowly push the valve/collet/shim system down through the forceps.

i spent more time on one valve than a complete valve adjustment normally takes.
 
G

·
i don't believe the 2valver shims sandwich/interlock like those of the 4valver... but yes the four valvers would be a beyatch to install because you have to relieve/machine the opener shim too.

the 2valver collets still see the same cross sectional area being loaded... makes it hard for me to believe that the mbp's would offer much more than the stock collets. about the only significant benefit i see with the 2valver shims would be ease in identifying orientation.

for a bike with higher mileage that's been adjusted and maintained i don't see it as an issue after the collets are work hardened, the clearances just don't change much. you might save cash if you installed the collets on a low mileage bike if you service it yourself. but the key there is servicing yourself, the last time i had to adjust my valves i swapped two closers for about $6 a piece 12k miles ago. that's not a lot of money to justify an extra $150 to me. i think you're just spending dough if you have someone else install the collets and still take in the bike for regular maintenance... you're still paying for the maintenance whether the valves are adjusted or just inspected.
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter · #12 ·
Thanks guys. I'm real interested to see how the clearances have held up since I adjusted the valves 3K miles ago. If the closers are keeping the clearances fairly well, I'll probably pass on the MBPs.

Chris: I'm surprised that you experienced such tight fits with the MBP collets. The ones I got to play with went together and came apart pretty easily. Absolutely no slop, but not wedging together either.

I will always do my own valve adjustments, so I have been studying this issue to see if MBPs would make life easier. I also have a fear of trusting a forcep to hold a valve from above, so I use a custom bent coat hanger wire with plastic coating to reach in through the spark plug hole and prop the valve up while the closer is off.

Mark J
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter · #14 ·
Definitely a static display (MBP's, of course). Valve by itself and not in a head (real easy to handle that way).
 

·
Registered
Joined
·
426 Posts
My 996 heads are boxed up and ready to ship to MBP. They will get the phase II port and valve treatment which includes collets and a red paint job.
 
G

·
i had no problems with fittment, they slid in the closer shim firmly, but no hammer involved.
checked clearences at 6kmi, no change since mbp install at 2800mi. :D
 
G

·
there is no chance of puting the collet in upside down. if you can't see the marks on the stock collet, you would have a chance of putting them in different from the way you measured them. i don't understand what chris was getting at. maybe it was 4 valve. its up to you, peice of mind.
i didn't think $150 was a waste.
i can't see how it would make shim changes any more difficult, i'm sure they will still need to be changed.
maybe after 15k it wouldn't make a difference with the stock collets.
i put the mbp collets in as soon as i got the bike, so i don't know the difference.
it does make sense that the stock collets would work harden.
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter · #18 ·
Thanks for the additional input OT_Ducati, and everyone else that has weighed in. I respect and trust the opinions of everyone who has chimed in on this, and am coming to the conclusion that this is one subject area where truly: "your results may vary".

So now that I'm teetering on the edge again about which way to go, I really can't wait to check those valves, compare the readings to the 'before and afters' from last adjustment, and look closely at the collets again. It just ain't gonna happen this week due to other stuff going on. :-/
 

·
Premium Member
Joined
·
3,677 Posts
i don't understand what chris was getting at. maybe it was 4 valve.
it was 2V. when letting up on the closing rocker arm, the closing shim didn't want to easily seat on the collets. and this was with several valves and a handful of shims, so not some random occurrance. i have a ducati performance 2V shim kit at my disposal and tried all the shims of a few different sizes to see if there was something to be done about it. this was done on zina's 2000 m900ie with the new "radiused" collets.

:) chris
 
1 - 19 of 19 Posts
Top