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Spec's on the two different valve adjustment nuts that are shown in the parts manual ?? Anyone.

RDMinor

Just got it firing!
Joined
Jul 26, 2020
Messages
8
Location
Florida
I have a 2010 Griso 1200 8V that was rollerized by a previous owner back in 2016 with some 16,000+ miles on it. I'm trying to get a fix on just why the parts manual calls out two different part numbers for the nuts used to set the valve adjusting at the rocker arm. In my Guzzi digital shop manual they are both shown as being #11. The first is referred as 'old' M1 (# 484819) and the second is referred to as 'new' M2 (# 879916). Beyond that there are no specifications. At least not in English.

Since I, like many others, have been working with the impression that 'old' indicated pre-roller and 'new' indicated a roller assembly the thinking is that part # 879916 is the correct adjusting nut for a rollerized engine while the 'old' one is for the previous non-rollerized engines.

So, first question, does the roller kit also include entirely new rocker arm assemblies and all that goes with it including the rocker arm adjustment rod as well as a new nut or does the swap resue the original rod and nut? If it allows for reuse of those parts than wouldn't the 'old' part still be used?
To further muddy the water the parts manual also shows that for the right cylinder head there are not only 2 numbers for the adjusting nuts but also two numbers for both the rocker arm adjusting rod AND the adjusting screw....WHILE the same manual when refrreing to the left cylinder head shows only ONE part # for each piece and that number is the 'old' or M1 part #


Is that clear as mud and does it mak any sense at all? How can the same engine have different part #'s doing the same job with the only difference being which side of the bike they're on. One side has only one part number for a certain piece while the other side has two parts with the with two different #'s for a part doing the same job as the one on the other side.

For those who know just what are the specs. for the adjusting nuts themselves. I know they are both M6 but there is most definitely a differnce in thread pitch?
Stein -Dinse states that the 'old' M1 piece 484819 is an M6 x 0.75 but I haven't been able to pin down the thread pitch for the 'new' M2 879916 nut.
One thing I know for certain is that part # 879916 will NOT fit the valve adjusting posts installed on my right cyclinder head and by eyeballing the threads they're a definite difference in the threads bwteen the existing nuts and the new replacement nut.
 
EDITED FOR CLARIFICATION:

Your assumptions about the information you have seen, is incorrect.

Nomenclature is critical here to understanding.

I wrote about this in detail here and there is even a picture of the rollerization kit components:


First, the parts fiche covers 2009-2014. Old and new do not mean what you think.

If you have a non-factory roller (“OLD”) motorcycle, the nut is #484819 for both sides.

If you have a factory-roller motorcycle, (“NEW”) the new part number with different pitch threads is #879916 for both sides.

If the nut #879916 does not fit your bike, then it wasn’t a factory-roller bike.

This matches your statement that it is a 2010 MY which has been “rollerized”.

So, if you have both types of nuts spread over different cylinders, then somebody has used mismatched parts when they performed a rollerization, because Moto Guzzi does not use different thread pitches on different sides of the same engine and the parts diagrams and listings also do not support this condition of your motorcycle if I am interpreting what you are saying correctly.

If you indeed have different pitch adjusting nuts on opposite engine sides, the you have what I believe to be a situation unique to your particular engine.

If you do not have this but rather, have discovered that your Griso utilizes the “Old” nut, then you are simply stating the obvious and you are incorrect in your assumption that “New” has anything to do with post-factory production, owner rollerization.

It does not.

It has to deal with factory production changes in 2012, after the discovery of the DLC failures.
 
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Didn't actually read my post did you Scott. I have a bike that started life without a roller cam but in 2016 at 16,000+ miles the previous owner had it rollerized.. By the way, it's easy enough to tell if you havbe a rollerized cam and doesn't take anything more than removing the valve cover to check. Something I'd obviously already done before I sat down to order the parts.

In trying to replace a knackered adjusting nut I ordered a replacemnt adjusting nut assuming, as you have above, that a rollerized engine would use 8799816. It doesn't. I tried both nuts I ordered and neither one would go beyond 2-3 threds before binding. Thinking I was being brain dead the removed on of the existig nuts and tried it on the empty post and it went on smoothly and easily while the 2 879916 nuts I had [purchased from Fowlers boundup quickly. I then lookied clsoe at both the new 879916 nut and the threads on the existing nut I had removed and the thread pattern is observably different.

Since my bike is one that was rollerized 6 years and 16,000+ miles AFTER it left the plant and the 879916 nut DOES NOT fit I have to assume that the kit reused at a minimum the rocker arm adjut rod and its adjusting nut. This is why I was interested in finding out specifically what the difference was between 484819 and 879916.
As I said I think everyone assumes that havingt two different part #'s indicated that all bikes regardless of when rollerized would use the new part #'s when my bike, at the very least, disproves that theory and that Moto Guzzi should have cleared that up. Even the current parts manuals are throuroughly confusing when you look at them and are trying to figure out what you need to repair your bike.
 
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So, first question, does the roller kit also include entirely new rocker arm assemblies and all that goes with it including the rocker arm adjustment rod as well as a new nut or does the swap resue the original rod and nut? If it allows for reuse of those parts than wouldn't the 'old' part still be used?
It does not per below, and yes you reuse the old items. Please (re-)read the paragraphs at the top of the page. Scott is one of the good ones here and wrenches professionally every day, like I do, and @john zibell - is another resident pro here.

 
That answers the question doesn't it. Those engines rollerized by way of the kit DO NOT use 879916 nuts or the adjusting rods etc. that appear in the parts manuals as either 'old' or 'new'. The 'assumption' that all rollerized engines therefore require 879916 and related pieces makes fools of us who believed that. That same assumption will end up having cost me about $35 in wasted money and an additional week or two in down time.

As for Scott he may well be "one of the good ones" as you say but it doesn't change the reality that he didn't read my post and the questions I asked. His response was not only abrupt and therefore somewhat rude but it was also entirely wrong as it turns out. My information was not incorrect since I made not statement about 'correctness' and I was pretty clear in my request to get information that pertained to my situation. One I did my best to explain.

As for wrenching I have little doubt that he has more experience than I but I've spent most of my 75 years under, over, and inside more types of cars working on virtually everything but transmissions as well as riding and maintaining my various and sundry motocycles since 1964 and I've learned something new in every one of hose years. One of those things is that I never know as much as I somethimes like to think I do.
 
Didn't actually read my post did you Scott…

Hello. Welcome. Let’s start again…

I’m sorry. You presume a great deal. Most of it incorrect in my opinion.

While I predict you will just be another drive-by poster based upon the tone of your original writing, I did in fact read your entire post including what you said, including your claiming different thread pitches from left side versus right side.

I also read your statement:

One side has only one part number for a certain piece while the other side has two parts with the with two different #'s for a part doing the same job as the one on the other side.

After reading what you wrote, I went exploring and checking. In my inquiries, I found that the online parts catalog at AF1 Racing, doesn’t mesh with your statements.

So, I offered a different possibility for the history of your engine.

Unfortunately, I had just spent the day dealing with somebody who I went out of my way to try and help but to which he just got nasty when he couldn't understand my explanation of what I did to repair his racing motorcycle. He upset me right when I had started to write that reply. Unfortunately, it was negatively affected by that event and that was not good. My bad.

I apologize for the confusion you experienced. I have edited my post to make it clearer. Maybe that will help.

The notations in the parts catalog are for factory production changes (factory roller engines) in the 8V engines. Not based upon a rollerizing kit or not.

So yes, I completely read your post and I still have a differing opinion of your situation, than you do because I understand what is being communicated in the parts diagrams differently than you do.

Having a different opinion than you does not mean that I didn’t read what you wrote. It means that the facts and I don’t agree with your statements and this is because I believe that you are interpreting the parts catalog incorrectly.

This is my opinion.

I do apologize that you found my reply, “abrupt and somewhat rude” because it certainly wasn’t meant to be. Just matter of fact.

Curiously, at various times in the past, some brand new people here, just like you, have complained that my answers were too verbose. (Kind of like this one) Go figure.

No good deed goes unpunished around here! 😆

The parts that get used in a rollerization and the parts that get replaced, are all well covered here over the years and available with SEARCH. There is even a photo of the kit components in the post I listed above on "Everything you Wanted to Know..." and I know several other photos in other posts as well.

You must have not used SEARCH or you would have found these.

In my defense, regarding my brevity this time out, I was upset in the process of writing it, short on time trying to reply to it and unfortunately, yes, it was clumsy and unclear. Again, apologies.

As I stated, I’ve edited the answer to make it more accurately reflect what I was trying to communicate.

What you do with the information is up to you.

I know how to wrench on Moto Guzzi motorcycles (I currently own 5, including a 8V), and I understand fully how the parts catalog is with regard to this issue. I wrote the guide about it here. SEARCH would have revealed it to you and provided you with more information.

I realize you are brand new here so you really don’t know diddly-squat about the extensive information that is contained within the indexed forums here. It’s been said over and over, SEARCH is your best friend here.

Contrary to your preconceived notion, you’ve stated nothing new. Your comments and questions are not some new revelation. There is virtually nothing you could ask regarding the 8V engines, (on all models), that has not be covered extensively in an exhaustive manner on numerous posts here.

So yes indeed, I did read everything you wrote. I love to read longer posts.

You just missed the info at the top of the page is all. The critical concept is to SEARCH first because this place isn't social media and it's been around for a long time and the information compiled here is exhaustive.

I understand. You missed that part because you didn’t read it.

I won't be unkind to you as you were to me, but simply say to you, “Isn’t it great to be a flawed human like the rest of us?”

Hmm…

So, again, Welcome to GuzziTech!

I realize you just got here and I hope that someday you will end up contributing something really good here.

After all, what you take from here doesn’t mean anything at all.

What truly matters, and the only real definition of what it means to be a GuzziTech member and Guzzisti, is what you contribute of value to others here.

Be happy.

👌🙏👍



Scott is one of the good ones here

Thanks Todd for the very kind words.
 
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I don't like leaving an inquiry just hanging and now that the problems been solved and the bike mis back on the road I think the issue needs to be broadcast to a wide audience than had been reached by Guzzi itself some 11-12 years ago.

If you've followed the posts above you'll see that GTM gave me a clear answer to the main question regarding the possible reuse of existing parts when doing a roller cam converstion. The answer was yes you could. The old parts in question are the very ones listed in the parts manual as 'old' to differentiate them from the other ones listed as new.

As a double check I asked Fowlers in England, where I had purchased the first set of 'new' adjustment nuts from if reuse was possible and their online parts man having been filled in on my problem checked with their tech department and found out that GTM was in fact correct about reuse of parts. Something he had not been aware of and something that their autyomated VIN check for ordering parts was not set-up to flag. As far as they were concerned every Griso with the leading VIn sequence as my 2010 used the 'new' adjusting pieces. There was no flag for those bikes that had been rollerized in the field with a kit that allowed some of the old parts to be used.

The reality is that my bike, which had been field rollerized in 2016 ay 16,000 miles by a previous owner, had in fact reused the original 'old' style adjusting pieces so that in order for me to replace any parts, in my case a bodged adjusting nut,I had to order the older pre-rollerized nuts.

I suspect that the actual number of such field rollerized bikes and the number of still working techs who actually did such field converstions on what is now a 13 year old bike is now in the single digits and the problem may never again surface. But if you happen to have a Griso 1200 8V that was rollerized AFTER it left the factory there's a fairly good chance that much of the rockerarm assembly and valve adjusting pieces connected to tyhgem are in reality the 'old' reused parts and not the 'new' parts used in the factory rollerized bikes.

While I'm not a "technician" I have spent 60 of my 75 years around both motorcycles and automobiles, have restored a few,been fortuante enough in my life to own and drive some of the world's great marque name plates from both the U.S and Europe, and spent 30 working years in management and eventually ownership of Chrysler and Nissan dealerships in the U.S. I've found that what the manuals say is not always the case, that parts are not as interchangeable as one may think, and that in actual practice how technicians tackle a problem is not always the way in which the factory manuals suggest they should.

This is just another example of what you may think you know is not what's really the case.
 
Curious. Didn't I say just that that above...

First, the parts fiche covers 2009-2014. Old and new do not mean what you think.

If you have a non-factory roller (“OLD”) motorcycle, the nut is #484819 for both sides.

If you have a factory-roller motorcycle, (“NEW”) the new part number with different pitch threads is #879916 for both sides.

If the nut #879916 does not fit your bike, then it wasn’t a factory-roller bike.

This matches your statement that it is a 2010 MY which has been “rollerized”.
 
Curious. Didn't I say just that that above...
I think if you read the entire series of posts in this thread you'd see that was NOT the point I was making. While you may have made that point before you weren't address the problem I was trying to get to the bottom of.
 
I think if you read the entire series of posts in this thread you'd see that was NOT the point I was making. While you may have made that point before you weren't address the problem I was trying to get to the bottom of.
I should add that there almost no central source that lays out the potential for error because of this obvious difference between 'old' and 'new'. The documentation available to most of us in the vartious manuals doesn't make a distinction between factory and non-factory rollers parts.

I now know that there is a difference but not because either my factory service manual or my factory parts manual told me there was a potential difference buit because I assumed (there's that word again) that a rollerizing kit would be the same at the dealer level as it would be at the factory. Had I personally contracted to have the upgrade back in the day I might...might... have learned that but I didn't contrat it the previous owner had it done.

I'll also add that in searching the threads prior to even making the inquiry I could not find any reference to this in the archives. Are there some? I still don't know because these archives like everyother forums archives seldom use boolean searchs but depend upon words and titles to threads in order to give you a list.
 
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