Dan M

You are missing something. Other than the threshold for overcoming the regulator spring, fluctuations in manifold vacuum have no effect on the pressure in the fuel lines. The regulator is just using vacuum to mechanically switch the regulator. Think of it as a regulator with a manual lever to throw to switch from low pressure to high. the "lever" that is getting thrown is the vacuum diaphragm. The regulator can be considered as on or off. "On" with vacuum applied allowing fuel to pass back to the tank at a lower pressure than "off". The fuel pressure is in the fuel circuit (pump, lines, injectors, and finally regulator) atmospheric pressure and manifold vacuum do not alter it. The regulator is the last component in the circuit, it blocks the flow back to the tank causing pressure in the system. When vacuum is applied to the port, it overcomes one of the springs via the diaphragm and allows fuel to pass more easily back to the tank reducing pressure. It only has two values, with or without vacuum applied, high or low, if you will. If there was a mechanical switch instead of a vacuum diaphragm there still would only be two values, how hard you pushed the switch would have no effect. When you apply vacuum, nothing changes until you get to the threshold when the vacuum overcomes the spring. Then the change is made and it remains that way until sufficient vacuum is released for the spring to relax. Whew. Pretty redundant here. Sorry if I beat the shit out of this topic.

One more thing. There seems to be some confusion about the relationship between vacuum and fuel pressure. There is none. Vacuum is just used to trigger a regulator at a specific value. Fuel pressure is governed by the regulator at two preset values. Let's say for the sake of agrument that the regulator applies at 15"Hg. and the fuel pressure spec is 35psi with the regulator applied and 40psi with it not applied. Vacuum is just the switching device. If the engine is producing less than 15" vacuum the fuel pressure in this model will be 40psi. If the engine is producing more than 15" vacuum the fuel pressure will be 35psi. The idea is high load = low vacuum ~ low load = high vacuum. This is why vacuum is a handy means of actuation. Make sense?

Where is that tongue in cheek emoticon when we need it?

STOP PRESS> After thinking about the whole .030 orifice question I decided to hook a vacuum gauge directly to the manifold with the brass nipple removed. The pulse on one cylinder at idle is more than 15"Hg! With the nipple off you can feel a puff of pressure between the vacuum pulses. The gauge bounces from the slightest amount of positive pressure to just past 15" vacuum. So, you are not getting the range of vacuum through the small orifice. Will it slow the operation? perhaps yes. Still, that regulator hooked to this engine will be useless, dancing between applied and not with every pulse of the engine.

No problema.

Is OK Jose. The dry clutch clatters.

Additional duty for the circuit just means slower reduction in fuel pressure (as vacuum builds); once the throttle plates open the vacuum falls instantly providing the boosted pressure.

Thought I'd jump in here. The chamber is very small and doesn't take very much "flow" to actuate it. A .30" port should be plenty, the longer the run through fine tubing, the slower the response but we're splitting hairs. Remember the vacuum pulls the diaphram against the spring, when the throttle plate is opened the vacuum falls off instantly and the spring slams closed. It is not like there is a large flow. It obviously has to be connected to manifold vacuum. I'm guessing the spring is overcome at about 10"Hg. If you are going to hook it up you should tee it to both manifolds as the v-twin pulses vacuum quite a bit. A vacuum tee should be available at any auto parts store. A fish tank tee will probably deteriorate rather quickly in this environment. Since it only reduces pressure at closed throttle, the likelyhood of a noticeable performance difference is nil. We've discussed before how the operation of the vacuum regulator is to increase fuel at throttle opening, kind of an accelerator pump effect. If you leave it disconnected you have the higher flow at all times which means with a stock map you are going from too rich at closed throttle to a more proper mix at open throttle. In theory, hooking it up will improve fuel economy but since it will only lean things out at closed idle the difference will be negligible. I posted long ago about the difference CO output at idle with and without vacuum to the regulator but I forget the numbers now. As luck would have it I rode the V11 to work today and should have time to sample exhaust gas. I'll report the numbers later. EDIT: OK here's the numbers at idle: Regulator disconnected - CO 4.74%, HC 64PPM, Lambda .883 ~ Quite rich 15"Hg applied - CO 1.73%, HC 32PPM, Lambda 1.01 ~ Pretty good for a non feed back system. Two things to think about. I connected a vacuum gauge tee'd to both manifolds. The pulses are huge. The gauge shows about a 7"Hg bounce at 1100RPM. That is a lot of stress on that diaphram. I don't like it. While 1.73CO is clean and green and 1.01 Lambda is about as efficient an your going to get, in the world of air / fuel cooled engines, that is a little lean at idle. Running it fatter (2.5-3%) is probably healthier especially in really hot weather.

This is great, commanding lead now. The editors of Vintage Bike must be thinking "What the hell? Moto Guzzi?"

Thoughts? I think that's a gap of about this much: l-------------l on the intake and this much: l----------------l on the exhaust. Give it a try but these specs may be a little too loose.

Yea, I was thinking the sudden activity may raise a red flag

Pulled to 15% three way tie for the lead

13% now. Edit: now 14% and all alone in 3rd place.

I like the idea and all of the positives. Not sure about the heat issue but the battery is above the motor on many BMWs and Ducatis. The battery can be at an angle, no problem. Just one thing. Make sure you can live with the pods before butchering anything. The intake roar and accompanying buzzing vibration from them will make it feel quite a bit different and that is not always good.

True enough. It all started yesterday when I was feeling a little slappy while talkin overlappy but now all are happy.

I never said any valves were open TDC compression. You noted that there is 360 degrees of rotation with the valves closed. There is not. There is 254. The issue we've been talking about is where the crank has to be when adjusting valves. My only point is while the range of crank rotation with both valves closed is wide, it is not 360 degrees wide. There is indeed overlap on all but TDC compression stroke. Both valves are closed from 128 degrees before until 126 degrees after. Beyond that range one or the other is open. And yes Ratch, I fully understand.

Docc, I used anti-seize in mine. Probably not the best thermo conductor but certainly better than air. The sensor was finger tight. No trouble unscrewing from the plastic.

I read Greg's post too quickly while drinking. Yes they are both in the meat of the base circle. I interpreted it as center of the base. My Sunday evening posts tend to be a little out of focus. So far as 360 degrees between ramps, I'm not too sure. Certainly cam duration plays a roll and it has to be close at BDC. I don't think I'd set lash near it. That ex valve has to be starting to open by the time the piston starts back up after combustion. Makes me want to pull a valve cover and see exactly when things happen. Edit: There is overlap at both ends. Valve timing from the V11 manual - Intake opens 22 degrees before TDC / closes 54 degrees after BDC. Exhaust opens 52 degrees before BDC / closes 24 degrees after TDC. That is 254 degrees with the valves closed during compression & power strokes. So you are off by 106 degrees of rotation. Did I convince you otherwise???

Most here including myself love and trust (I'm knocking on my desk right now) these bikes but some things are just not meant to be. It does seem you are having more than your fair share of trouble. Perhaps Luigi and Guido were both hung over the morning yours was assembled. I think if mine were as much trouble and I couldn't get it sorted I'd probably get rid of it. Who wants to be 100 miles from home and not trust their bike?

Both cam lobes are not exactly at the base when the piston is at TDC compression anyway. If they were that would mean both intake and exhaust open at the same time. Right? TDC (compression stroke) just insures both are off of the ramps. With valve overlap and exhaust scavenging there isn't a full crank rotation before you hit either ramp but it is a pretty good distance.

Very nice. A satin black one caught my eye at a dealer about a month ago. Quite lovely. Not ready to part with the V11 yet though.

No accuracy needed at all. As Ratch mentioned in an above thread, the back side of the cam is a pretty big place. You can get where you need to be just by watching the valves as you rotate the motor. You don't even have to take the cover off if you have a stand. Just put the trans in a higher gear, pull the spark plugs and rotate the engine easily using the rear wheel. Watch the valve close, turn it slightly farther and adjust. Once the covers are off you can adjust all four valves in less than 10 minutes. There are many ways to determine TDC from burping it like ratchet describes, a slim screwdriver or straight piece of coat hanger in the spark plug hole or most positively with a dial indicator. Once found you can paint marks perhaps to use checking timing scatter. Beyond that the info is not really needed.

Careful now, a noose? some may think you're making a political statement about the death penalty and take offense.... could be the beginning of a good thread gone bad. You may offend the topic starter....