Engine shuts down.....

[pete roper]

Huh!?! What is your point?

 

Master of the obvious!

 

I disagree.

 

 

Jeez! didn't take long for my reply to get taken down! Who's the moderator here!?

 

Pete

[Marty]

Thank you all so much for your various comments and counter comments. I was amazed at what I spawned! It's going to take me some time to try the various things that were suggested.

 

I'm interested in the valve clearance issue. I did not think I was using some "US" spec., because I was using the factory shop manual and owners handbook which are multi lingual and the spec is the same in all languages (0.1mm and 0.15 mm-- and actually .004" and .006" are very slightly looser than that due to conversion factors (i.e. 0.1mm is actually like .0039")) Formerly when I set valves I was using an inch feeler gauge so those are the clearances I have it set to (4 and 6). Recently I got a metric feeler but I had to ask my Snap-On guy as nobody else had one. I'm willing to try different clearances as recommended, but I'm not so sure I want to deviate too far from factory specs. I have not seen any mention of US specs being different, etc. However it is worth noting that my OLD Guzzi (Ambassador '72) uses .1 and .2 (4 and 8 thou). I remember being surprised the first time I looked inside the V-11 valve cover thinking it was basically no different than the old Guzzi.

 

To my mind valve clearances have two functions: one, to avoid burning valves by not allowing the gap to completely close up when hot, thereby leaving valves slightly open and liable to burn; and two, to position valves precisely to have optimum valve timing. In other words, if the gap is too small, the valve opens slightly earlier than intended, and stays open shorter than intended, and if the gap is too large, the valve opens later than intended and stays open longer than intended. This can be seen in the use of "valve timing checking valve clearances" which are sometimes specified in various shop manuals (not noted in Guzzi books, this is a general comment)--- that is, set clearance for valve #1 to say .030 and note on degree wheel exactly when valve begins to open, or something similar. I recall using this technique to determine that the cam in the engine of my '57 MG Z Magnette 4 door saloon was in fact not the Z cam but the MGA one instead, which was a performance upgrade on the part of a prior owner.

 

Thus, messing with valve lash clearances messes with valve timing, so I'm concerned.

 

I was tickled to see the discussion of setting valve clearances and who could get it right etc. etc. I think it takes a certain feel, but, it doesn't take as delicate a touch as setting an ignition points gap with a feeler gauge, because when you do that you have to worry about not pushing back the points spring. I think with valves you are unlikely to really have much of an effect on the spring! One day soon I'm going to have to learn how to set the valve lash on my new Ducati which has desmodromic valves. The dealer thinks I should let him do it, but that's not my style.

 

Thinking of the Ducati, which is a Sport 1000, I recall a recent conversation with a Guzzi enthusiast who was the salesman in a nearby Ducati/ Honda dealer. He said the sport 1000 is a new bike trying to look old, but the V-11 is an old bike trying to look new!!!!!!

[pete roper]

The reason why you'll find most engines have a 'Setting' or 'Timing' clearance that differs from the running clearance is that most cams have what are known as 'Quietening Ramps' on the bottom of the opening and closing flanks of the cam where they meet the base circle. When the followers are on the ramps the opeing is incredibly gradual for several degrees of the cam's rotation so it is very hard to time it accurately.

 

By opening up the clearance for the timing proceedure the valve won't start to move until the follower is past the ramp and actually on the base of the opening flank making timing more accurate and easier.

 

Pete

[guido]

I have not followed the discussion here in detail, but I would suggest that you could be looking at fuel starvation. If so, then I would check the pet cock filter and clean it out, and also the fuel filter either in, or under, the tank.

As for valve clearance discussion, a noisy tappet is a happy tappet seems to be a good saying, and very apt for Moto Guzzis I think.

[Guest ratchethack]

Take any two of us amateur wrenches and all bets are off as to being within .001" of one another, especially after trying to tighten down the locknut without throwing off the setting.

Dave, no decent mechanic or half-competent shade-tree tuner would ever dream of trying to tighten the locknuts without throwing off the setting! Final reads are NEVER properly taken on screw-adjusters until AFTER the locknuts are firmly snugged-up. Any halfway decent wrench will be able to match the setting of another +/- .001".

Huh!?! What is your point?

Master of the obvious!

I disagree.

Well, Dave, since you've asked -- as your post above illustrates so well, there are those hereabouts who seem to be so lacking in proficiency with the obvious, that the obvious must be pointed out. Many seem to need this on a regular basis. There's no shame in lack of knowledge, only in spouting incorrect information without any basis in knowlege about what one is talking about, as if one had expertise that one obviously lacks.

 

In your post above, you would seem to be indicating that you place yourself in the category of "us amateur wrenches", with the intent to include others. Now when you refer to such a group of individuals "trying to tighten down the locknut without throwing off the setting", I reckon this has a clearly understood (and equally obvious) meaning -- at least on this planet.

 

If you adjust your valves exactly as you've described above, Dave, my point is that you're suggesting an impossibility, that you're obviously doing it incorrectly, with incorrect objectives, and that you may expect sloppy and inconsistent results, poor engine behavior and lack of tunability as a result. Now it wouldn't suprprise me in the slightest to know that many, including yourself, Dave, do exactly what you've described. I've actually seen worse, and I've read posts describing far worse both here and elsewhere. So pointing out the obvious here would seem to be quite necessary to make it clear to anyone reading this who may not fully understand that what you've described is grossly incorrect and/or incompetent valve setting technique. . . [sigh] . . .

 

If you can't consistently match a valve settings to +/- .001" on a twin or multi cylinder motor, you aren't competent enough with basic tools to do the job well enough to have a very smooth running motor, and you're well advised to hire a halfway decent tuner to do it for you.

[GuzziMoto]

Sorry for polluting the post.

If you can't consistently match a valve settings to +/- .001" on a twin or multi cylinder motor, you aren't competent enough with basic tools to do the job well enough to have a very smooth running motor, and you're well advised to hire a halfway decent tuner do it for you.

I've known many a professional mechanic who don't adjust valves to within .001". That may have something to do with the fact that most specs call for valves to be adjusted to within a range, not to a specific value. I suspect that would be infering that it's not that critical, that there's some margin for error. If you are going to adjust them to exactly a given value, you would be better off using a dial indicator as suggested rather then a feeler gauge in my opinion.

[Guest ratchethack]

Sorry for polluting the post.

 

I've known many a professional mechanic who don't adjust valves to within .001". That may have something to do with the fact that most specs call for valves to be adjusted to within a range, not to a specific value. I suspect that would be infering that it's not that critical, that there's some margin for error. If you are going to adjust them to exactly a given value, you would be better off using a dial indicator as suggested rather then a feeler gauge in my opinion.

Hm. Please note that what you've said is NOT what I've said. You're off by 100%.

 

Within .001" is exactly half the tolerance of +/- .001". A tolerance of +/- .001" provides exactly a .002" range.

 

The Guzzi manual doesn't spec a range for valve setting tolerances (nor does any manual I've ever used, and that'd be a moderately sized stack), but again, if you can't match your valve lash from cylinder to cylinder within +/- .001", IMHO you shouldn't be attempting it yourself. And I reckon this ain't just me.

[Dan M]

Even if I could match Ratchet's feeler gauge accuracy by using a dial indicator, I don't see why I would bother.

I think I am accurate to within about .0005" of my own settings, and that is accurate enough since we can't even agree on using .004"/.006", .008"/.010, or somewhere in between.

But if Marty set to a rounded out .003"/.005" (.0034"/.0054" by dial gauge) thinking it was .004"/.006" I see a potential problem. But I even see a potential problem at .004"/.006". Of course not as bad as setting it to .002"/.004" as some have thought to be US spec, but I doubt that happened.

 

Just one question. OK, three. How do you measure accuracy to within .0005 without a dial indicator?

Do you have feeler gauges in graduations of less than 1 thousandth of an inch?

Can you feel the difference with your feeler gauges of a 5 ten-thousandths variation?

That's pretty impressive. Enlighten me please.

[dlaing]

Just one question. OK, three. How do you measure accuracy to within .0005 without a dial indicator?

Do you have feeler gauges in graduations of less than 1 thousandth of an inch?

Can you feel the difference with your feeler gauges of a 5 ten-thousandths variation?

That's pretty impressive. Enlighten me please.

Yes, I can feel to that difference.

For example if you set two tappets to two measurements with a dial gauge to .0060 and 0065 I could tell the difference and if I sit there battling the lock nut for an hour, I could adjust it so that they are closer. How much closer, I don't know, but closer.

Ratchet on the other hand and the 50 other half decent shade tree mechanics on the forum, can start with a pair of tappets at .005" and reset it so that they are all between .0055 and .0065".

I can't guarantee that I am one of those 50, but Ratchet and Skeeve are that good and expect most of the forum to be that good, right?

Of course my claimed margin of error is twice as good as their claimed margin, but I am measuring against myself, not the golden dial gauge.

If I were to try to reach .0060" I might end up with .0054 against the dial gauge, but not Ratchet and Skeeve.

[Guest ratchethack]

Ratchet on the other hand and the 50 other half decent shade tree mechanics on the forum, can start with a pair of tappets at .005" and reset it so that they are all between .0055 and .0065".

I can't guarantee that I am one of those 50, but Ratchet and Skeeve are that good and expect most of the forum to be that good, right?

Um, Dave.

 

This (again) is yet another example of exactly why the obvious needs to be repeated so very very often. . . [sigh] . . .

 

You've made the same critical mistake as GuzziMoto. It's a margin of error of 100%. Please review post #24.

 

Maybe a very very simple algebraic expression will help.

 

(within .001") x 2 = (+/- .001")

 

or

 

(within .001") = 1/2 x (+/- .001")

[docc]

I'm sure I can pi$$ 0.001" further than +/- 1/10 of 1% of the Chosen Fifty.

 

I'm sure you guys can see how really pedantic this is. it doesn't surprise me for midwinter where there is a meter of snow in front of the shed, but California? I need to send you fellas a couple bucks for gas . . .

[Guest ratchethack]

I'm sure I can pi$$ 0.001" further than +/- 1/10 of 1% of the Chosen Fifty.

 

I'm sure you guys can see how really pedantic this is. it doesn't surprise me for midwinter where there is a meter of snow in front of the shed, but California? I need to send you fellas a couple bucks for gas . . .

Pedantic? Possibly. And if you consider how badly many people misunderstand valve adjustments and significant tolerances, you might consider much of it stupid, even. But as usual, there's at least a better than even outside chance that somebody could actually learn something. It's been raining for 4 days and it's frickin' COLD. I'm talkin' frost on the pumpkin, COLD. I wish that deluded contrivance for the Philistines, Global Warming would frickin' GET ON WITH IT! . . . But now the sun's comin' out and I'm off for a ride.

 

Since oil topped $100/barrel last week, our gas prices are about to shoot up another $1.50/gallon by some estimates (yours maybe another $1.00, possibly more). But if you really want to send gas money, by all means.

[Skeeve]

Yes, I can feel to that difference.

For example if you set two tappets to two measurements with a dial gauge to .0060 and 0065 I could tell the difference and if I sit there battling the lock nut for an hour, I could adjust it so that they are closer. How much closer, I don't know, but closer.

Ratchet on the other hand and the 50 other half decent shade tree mechanics on the forum, can start with a pair of tappets at .005" and reset it so that they are all between .0055 and .0065".

I can't guarantee that I am one of those 50, but Ratchet and Skeeve are that good and expect most of the forum to be that good, right?

Of course my claimed margin of error is twice as good as their claimed margin, but I am measuring against myself, not the golden dial gauge.

If I were to try to reach .0060" I might end up with .0054 against the dial gauge, but not Ratchet and Skeeve.

 

It's seriously not that difficult to use feeler guages, the key being that to set a .006 clearance, you'll need the .007 & .005 feelers as well. Most people who've never been told how to use a feeler guage don't realize this. On a .006 setting, there will be light drag on the .006 guage, none on the .005, and no entry by the .007 [w/o noticeable application of force.] Quite literally, everything is measured by "feel," hence the name.

 

Locknut tightening affecting the adjustment you just made can be a pain, esp. when accessing them out of position like when lying under a VW Beetle [the real ones, not the Golf w/ swoopy bodywork they presently sell as a "Beetle"], but w/ the easy upright access to Guzzi valves, this shouldn't be too hard to overcome.

 

And I don't know why you group me w/ Ratch as being "all that good;" the fact is that I'm blessed w/ more than my fair share of thumbs when it comes to things mechanical [my bro' Paul got all the spare fingers, I guess: he's a mech. wiz!] & if I can manage, I quite rightly expect that the majority of forum members who actually give it a reasonably earnest try can do so as well. Does this mean I can feel the difference btw .0055 & .006 w/ my .006" guage leaf? No. It just means that when used correctly, feeler guages enable the trained user [eg: everyone who just read & understood my instructions above] to generally achieve a clearance within plus or minus .0005" of the selected guage. If you had a guage set w/ a .0005" leaf, then I expect that would enable the average user to achieve plus or minus .00025" accuracy, but there's a limit to how accurate & small you can take this: fortunately, we don't need to go to those extremes on our "old ditch pumps."

 

Ride on!

[Dan M]

Yes, I can feel to that difference.

For example if you set two tappets to two measurements with a dial gauge to .0060 and 0065 I could tell the difference and if I sit there battling the lock nut for an hour, I could adjust it so that they are closer. How much closer, I don't know, but closer.

Ratchet on the other hand and the 50 other half decent shade tree mechanics on the forum, can start with a pair of tappets at .005" and reset it so that they are all between .0055 and .0065".

I can't guarantee that I am one of those 50, but Ratchet and Skeeve are that good and expect most of the forum to be that good, right?

Of course my claimed margin of error is twice as good as their claimed margin, but I am measuring against myself, not the golden dial gauge.

If I were to try to reach .0060" I might end up with .0054 against the dial gauge, but not Ratchet and Skeeve.

 

 

How do you know? In earlier posts you said you wouldn't bother with a dial indicator. This is why I asked how you know you are within .0005". Are you saying that you checked them with a dial, they were .0005 apart, and you went back with your feeler gauge and felt the difference? Was this for science? Seems to be a great deal of time to spend by a person who does not want to bother with lock nuts.

 

Ratchet (and other than actually being a professional mechanic; myself) and the 50 others are satisfied at within .001 as Ratch said +/-. That's +/-. Did he say +/-? I'd interpret that as no more than .001 greater or .001 less than spec. That's a .002 spread my friend.

While I agree that a dial indicator would be the most accurate way of checking this clearance, after adjusting valves for decades, hundreds and hundreds of them, I've never set up my dial indicator nor have known any other professional to do so. While I feel that I've developed a pretty sensitive touch in regard to how that gauge feels when you have it right,(which by the way, varies from engine to engine) Being able to say how many ten thousandths difference there is from valve to valve by feel is not likely. Unless of course it's you doing it.

[docc]

Pedantic? Possibly.

Sorry. I'm sure I was more crabby this morning. But, it is awfully tempting to get in the "within" 0.001 debate. Harder yet to get into what one can "feel." Being trained to palpate (feel biologic tissue skillfully) we used to practice finding a hair under 200 pages of the Guyton's physiology book. I can tell you some could feel more than others.

 

"Within" 0.001 seems to me to be +/- 0.005. If it were to be +/- 0.001 that would be a spread of 0.002, or "within" 0.002. (There, I got he pedantic part off my chest ).

 

I do agree with the 3-blade method. And the requisite air-cooled VW Beetle training. ("When you can adjust the VeeWee's valves on youir back in the dark and rain, you can have a Guzzi, Glasshoppa. )

 

I'm shocked no one has yet used the phrase, "stone cold."