guzzijack
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Posts posted by guzzijack
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It doesn't seem to exhibit signs of being overly rich when cold as described by many others; why this should be is a mystery to me, but I'm not complaining either.
I noticed MG's have a brass sensor holder advertised (part #30163301, $29.95). Does anyone know if this is suitable for the V11? If so, surely it would be a cost effective alternative to the very fragile plastic stock unit.
Your bike is probably running well because you have already filled the holder/sensor gap with a suitable heat conducting material, (maybe also the EFI is set up well?). The part number looks good for the replacement brass holder but why bother? IMHO, unless I had a plastic holder which was damaged in some way I'd just do as you have done and fill it with copper grease or a more dedicated thermal conducting paste. I think people are getting too wound up about changing them.
GJ
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Oh boy, been away for three weeks including taking the slow train across Canada and came back to find this 'interesting' thread still running
I started to scroll the pages in reverse order but gave up after my eyes started bleeding so......... did anyone discover if Dave has actually stripped and lubed his own cush drive yet?
GJ
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EDIT, now that I think more rationally.....what I said below is not true. The wider end would need more holes to allow for more travel. But due to more force at the narrow end there should proportionally be more holes to width at the narrow end....which was what I was thinking originally, but neglected to add travel to the equation
But the puck is a 3 dimensional object and flexing forces are not limited to one direction. The narrower (apex) end of the triangle is actually the thicker/deeper part when viewed side (edge) on. Where is the rationale in limiting the imitation of a Toredo Navalis on speed to the one plane? Why not drill that thicker part of the puck from the side elevation to better distribute the flexing?
BTW: As you haven't actually serviced the cush drive and ensured that the drive plate is at least free to move on your bike, it is almost certain that you are running with a locked rear drive - given that Mandello is the centre of a grease free zone
Bite the bullet and commit yourself to replacing the button head retaining screws, (if need be), and at least make sure the drive plate is free to move on its spigot. Your clutch, gearbox, UJ and drive shaft will thank you for it. 
GJ
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Unlike Greg and Ratchet, I have no experience drilling holes in the rubber and opening up years later. I don't even know how firm the rubber is.
One question. Have ever taken the cush drive apart and serviced it on your own bike?
Gj
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I've now had a chance to get the bike out & give it a good run since I liberally greased the cush drive.
I must say there is a difference that is noticeable
It is a little smoother between shifts.It was worth the three cents worth of grease that it cost me, but its nothing to brag about either. Hey better is better I suppose
I guess this illustrates the point I made in my previous post about, let's see, five pages ago
. If the average owner/rider just took the time to maintain the cush drive as per, then it could at least perform as it was designed to do. Anything over and above that may improve matters - or maybe not, (insert sounds of disintegrating rubber pucks, crashing vanes and mangled driveline components 
).GJ
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After having just been into my cush drive & cleaning & lubing it, I'm really surprised that such a small simple thing has generated 53 responses in just a few days. I have to admit it is fascinating to watch some of you peel this onion until theres nothing left to discuss about it. However the way its looking theres at least another hundred or so posts left before at least one of you get tired of it
Richard, I think this could make at least another 4 pages before it runs out of steam.
By stripping, cleaning and lubing your drive I suspect you've already achieved 100% more than the majority of owners will have done and it will no doubt help with drivetrain longevity! Modifying the cush by drilling and/or removing rubber wedges can be 'the icing on the cake' but I think you/we have to take a common sense approach to the bike it's being applied to.
Doing the full Monty on a '72 era bike might be spot on if you consider that the cush drive is, in typical Guzzi fashion, massively over engineered right from the start. I'm just advocating caution in undertaking such radical hole surgery and removal of 50% of the components and effective bearing surfaces on bikes that are throwing out double the RWHP.
Each to their own but as I said in my post above, I've seen what happens in this area even when we thought the component specified was beyond actual requirement - and on a bike with less RWHP than the sport Guzzis produced since the mid '90s.
BTW, I can't see an emoticon for 'tongue in cheek' but I think BFG might have a use for one to avoid the usual Transatlantic confusion
GJ
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Jack, I mostly agree exactly with your take. I edited my post above, recalling that I may well have used 4 holes per block rather than 3. A remembery is a terrible thing to lose.
Frankly, I don't think it much matters how many holes you use or how large, if they're well placed. I was so pleased with the driveline smoothness using the full complement of blocks that I haven't tried going to 3 pairs, though this is of course always an option.
Agreed
See my edited post above for the reason I'm exercising caution on this subject.
Incidentally, I would bet a penny to a pound that the majority of guzzis out there are running around with totally rock soild seized cush drives anyway. Even without modifying the rubbers, the simple expediant of stripping, inspecting and lubing the unit at major service intervals would make a major improvement to driveability and length of life of drivetrain and clutches.
GJ
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Hubert, as mentioned previously, I have over 20K miles and 3 years on this modification. In my case, I used 3 larger strategically place holes of 10 mm in each block. IMHO the large hole vs. small hole argument is only splitting hairs. I b'lieve that either would work as well and as effectively as mine has over the years.
While this ain't brain surgery, IMHO, it does take a base level requirement of common sense to understand, and perhaps a little shop-level experience and knowledge of the way the materials work and interact -- nothing more.
BAA, TJM, & YMMV
Okay Ratch you have 3 x 10mm holes drilled, (how many pairs of blocks left in?), I have 5 x 6mm holes with all pairs left in. I see in Gregs first photo of a drilled rubber that 17 holes are in there and he has only left 3 pairs in the drive.
I get the feeling, and it's no more than that, that there should be at least all 6 pairs left in on the big twins with higher RWHP. If the 3 pairs of swiss cheeses that are coping with up to 100bhp or thereabouts split or compress themselves to buggery and then fragment you are going to have an enormous amount of slop running up the driveline when both going on and off the power. I'm not going to risk it. The amount and positioning of holes and leaving them all in place as I described earlier gives a noticeable improvement in driveability and I feel secure about not having problems further down the line.
GJ
EDIT: I have a reason for being cautious in this respect. Back in the early '70s I had an early Honda CB750KO series with big bore 900 kit, yoshi cams etc. etc. to which I fitted a pair of the first available mag wheels which I bought from a european racer. We had to make up a custom cush drive for the rear wheel/sprocket carrier and first used an adapted automobile cush drive assembly from a mini cooper. Lasted about 2 hours before all the rubber split and the carrier started to spin. Ended up making a custom assembly out of machined billet with captive rubber inserts which were about as hard as the stuff Guzzi use but in a different format. There are enormous forces being transmitted in there.
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This is 'thinking out loud' mode, so I'm not stating facts only opening this up for a bit more discussion
The basic Guzzi cushdrive with its 6 pairs of rock 'ard biscuits, (hardtack?) have been fitted to big twins since when? V7Sport or even earlier?
Those bikes made what - low 50s bhp at the rear wheel? If correct, I can see the need to drill all the cheese triangles and even remove 50% of them for the lower powered bikes. As RWHP has in some cases doubled since then maybe there is a need to think about how much you need to aerate the blocks and even the posibility of keeping them all in there.
On the advice of Phil A on my V10 I've done the drill thing, although I think Greg has gone a bit overboard with the bit - I used a 6mm hollow tile drill and made one hole in each corner of the wider end and two holes on the centre line above it. Then flipped the wedge over on its side and put one further hole through the thickest (apex of the triangle) section. I left all the rubbers in and it gives a noticibly smoother ride but I think I'd counsel against going as radical as Grag has done on any V10, V11S or Daytona RS etc.
GJ
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GuzziJack wrote "...with an 8mm washer above that which, it so happens, just bears on the outside rim of the master cylinder."
As I understand it the 8mm washer placement on the rim allows for the added spring to assist the internal spring, and more importantly it assists it past the point of negative free-play, so that there truly is free play.
Exactly. The upper washer is the bearing plate for the spring and as it, (the washer that is), is only in contact with the bottom of the master cylinder BODY it can have no influence plus or minus on the piston - only to assist the return of the rod and lever. Certainly seems that some people feel that something like this will help the less than perfect O/E setup.
GJ
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Beats my bit of inner tube hooked round pedal!
KB
PS (How you getting on w the Sport Demons on the Tonti GuzziJack?)
Well I had to improvise because all the bikes have tubeless tyres of course
I'll let you know about the Demons when we get back from the run down to the Troffeo Rosso week after next
Cheers
Graham
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I've started a new thread for this one as the 'V. hot brake caliper' one would swallow it whole in the debate about the laws of physics and Noether's Theorem
Following my own dragging rear caliper and burnt disc scenario - no debate about what was the cause please gentlemen - I thought the return of the lever to the 'at rest' position could do with a bit of beefing up.
Here's what I did:
Consists of a 6mm stainless washer above the lower rose joint; a reasonably stiff spring in extension which neither binds on the actuating rod nor requires any noticeable force to overcome it; a further 6mm washer above the spring with an 8mm washer above that which, it so happens, just bears on the outside rim of the master cylinder. Both of the top two washers fit neatly and are held in place under the rubber boot.
Seems to work well and might even prevent dragging caused by those with Charlie Chaplin feet who rest on the lever while riding
GJ
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As for a piston's coating, be it chrome plating or anything else, just how hot does the piston need to get to lift the coating? Glowing red? How do the seals cope with these temps without complete failure? I've never seen a caliper piston's surface damaged by anything other than rust. If it lifted could it have been faulty to begin with?
I think with my own overheating scenario it was a bit difficult to diagnose which was cause and/or effect. The bike had been sitting for a few years prior to my ownership so I gave it a full service and checked the brakes out fully. However, the rear caliper must have been dragging intermittently as it never showed itself when I examined it but I'm guessing that (maybe?) the seals had hardened to such an extent that the pistons were not retracting fully - but only intermittently and not to any noticeable extent.
After the grand finale of the smoking disc episode when it did stick on, I stripped the caliper and found that the seals on one side were toast and the piston had blistered the teflon coating. So okay the seals may have degraded due to to age and lack of use but the piston coating blistering? That's why I put it down to being caused by the heat.
GJ
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I don't see any mention made of a modification I've done to the brake linkage on my V10 after my own caliper jam.
To ensure that the lever returns positively I have placed a small spring working in extension over the actuating rod 'twixt brake lever and master cylinder. It bears on a small 6mm washer at the lever end and a larger outside diameter washer (8mm) which is located and retained under the rubber boot on the m/c.
GJ
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I agree with all of this Martin. When inspecting the caliper it will be obvious if there is trouble before reassembly. (condition of visible dust boot, how smoothly the piston retracts...)
And yes contrary to popular belief if any brake is dragging enough to overheat, it would be tough not to notice before it got so tight as to cause catastrophe.
Er, is there a dust boot on the caliper? I thought there were twin seals on the piston but no dust boot. And BTW if the teflon type coating on the piston has lifted slightly due to heat or one of the seals hardened for the same reason, it is possible for the brake to drag enough to overheat and not be noticeable - or is my Centauro so much more powerful than a V11S that it overcame it
(flak jacket on
)GJ
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I agree those caliper piston seals need to be looked at for heat damage. By design/application they're selected to handle high heat but those pictures show an extreme heat situation.
I'd also have a serious squizz at the pistons as well. After my own caliper and disc 'afterburner' experience which was mentioned on This thread I found that the Teflon type coating on one piston had blistered and lifted.
BTW. Has anyone who maintains that Brembo do a seal kit for this caliper actually managed to get one yet? If not Ian ellison now has them in stock at near to £40 inc. pads.
GJ
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How do you check the initial gap? With something like chewing gum, or can you see the gap? Or do you measure from the hole down to the wheel and compare this with the length of the sensor?
If you can get the 'blunt' end of a verier caliper down the hole just measure from where it bottoms out to the machined face the sensor sits on. Measure the length of the sensor body, subtract it and you should be able to deduce how much shim is needed. If it's a sensor replacement job and the bike was running fine before it went bad, just compare the two sensors and (hopefully) you can leave well alone.
GJ
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Try this test.
Key on, wait for prime to finish, crank for 1/2 sec. Do you hear prime now? If not it sounds like the phonic sensor (rpm pickup).
I'd try jiggling connectors.
We had a V10 Centauro do exactly the same thing recently while I was test riding it, (getting over to the hard shoulder at 120mph with a dead engine was fun
).That was a phase sensor as Cliff suggests and on a '97 bike as well. I checked my own '97 Centauro when we got back and the sensor on that was exhibiting the same bulging around the circumference. Might be worthwhile getting a sensor from Moto Ecosse for £32.50 and even if that is not the cause it will be handy to keep a spare on the bike - a duff one will kill your engine dead.
You'll need to tell Stuart or Robert if it's a 2 or 3 wire one
GJ
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Skip,
Use the forum search function and you'll pull up a LOT of info on this subject including VIN numbers of the bikes affected.
I did it about a year ago hoping to verify if the engine and gearbox I bought on eBay were subject to any recall work. Unfortunately, for me it's all done on VIN numbers and not the engine numbers but I managed to score a recall kit for £10 so had it available whether needed or not
There are a lot of postings on the subject but if you wade through them you will find the information your friend needs.
Graham
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Here's my
FWIW.The validity of ensuring that the temp sensor is making good thermal contact with the pocket in which it sits - either plastic or brass - was brought home to me when Pete Roper plugged his Axone into a V11 Jackal when he was up here in the UK last time. The owner was reporting bad MPG figures and, surprise, surprise the temp readout for the ECU on a fully warmed engine was only something like 38 degrees, (I think, correct me if I'm wrong Pete).
After whipping the sensor out and filling the plastic holder with copper grease, the temp readout was immediately in the upper 70s and the owner has since reported better driveability and higher MPG figures. I don't think the brass pocket will make a lot of difference to the above scenario but then again I can't directly compare the figures I'm getting from my Centauro with the brass holder, as that will always run hotter than a 2 valve engine.
Re. the phase sensor - I would urge anyone with a V11, V10 or any engine that uses one to spend around £32 and keep a spare on the bike. The previous poster was either very lucky or very experienced if he could identify his going bad. I had one go out on another Centauro while tooling along at about 120 mph and they don't give you any notice
It's the one thing that will kill an engine dead and cannot be bypassed or a workaround done. So get one or keep your recovery cover up to date!Now, how about those timing gears Mr Roper?
GJ
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Anyone in need of any Brembo calipers, MCs or spares might like to contact IanE Racing. I've just had an email from him stating he can now do even better deals on Brembo than before - he quoted nearly half the price of other suppliers on the rear caliper.
GJ
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Graham
the rear drive boxes of Centauro and V11 are very different.
The Centauro sports the rear drive introduced with the Daytona which is a slightly modified box common in every Tonti Guzzi.
The V11 box is a newly designed one that is only used in the V11 vehicles.
I doubt there will any bearing fit into the other box.
I don't think so very different in this area! Maybe the very first Daytona series - Daytona 1000 - used a totally different modified Tonti big twin drive box and bearing but the Centauro/DaytonaRS/Sport 1100i use the same roller bearing as the V11Sport, part numbers 92252225 & 92259025 but maybe with the inner retaining washer residing with the bearing in the outside part of the case.
Graham
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Looking at replacing the R/H drive box roller bearing on a '97 Centauro which I believe is the same as the V11Sport? Bike is currently being ridden (carefully!) on a tour of Euroland and will be back ay my place in 10 days or so and I want to get the parts in and ready to do the work - sort of a slo-mo pit stop
Anyone have the bearing number or spec or is this one of those wierd sizes that I have to go through the dealer network to source and hope that Italy haven't already started the pre-holiday wind down of the parts supply.
Looking at the parts book it seems to be capable of being removed from the offside with no other parts involved so should be a simple out and in job - or is it?
Advice welcome.
Graham
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Unless someone has boged the seal or piston on disassembly I don't know why
the need for seals. This is the same caliper as a lot of the Ducatis use....
It has a composite piston....no rust...etc...
I have had mine apart,cleaned, and reassembled with no problems and
50,000 miles
unless its leaking ...clean it and reinstall
Well, in the case of my V10 - which is where this thread started - the bike had been sitting in a garage for at least 4 years prior to my ownership. The seals had obviously gone off as the piston was intermittently not returning out of contact with the disc causing overheating and finally leaking - it wasn't a problem with the piston/seals in the master cylinder, that checked out OK.
When I stripped the caliper the seals crumbled to bits and one piston had blistered what appears to be some sort of Teflon coating so no, it wasn't possible to use the components again.
There appears to be a lot of statements from people about the supposed availability of seal kits for this caliper, has anyone actually had one in their hands yet? FWIW I ordered one from one of the suppliers quoted above - Motomecca - and what I received had the correct part number as described on their parts listing but is for a different caliper. Other dealers/outlets stated that no specific kit was available for this caliper.
Unless you have actually had a kit in your hands to compare then I suggest that it is not available and some dealers have erroneously listed a different one.
GJ
Making a Cushier Cush Drive
in Technical Topics
Posted
Never need an excuse to hit the beer chiller in the workshop
Although I'm genuinely surprised that you haven't at least taken the opportunity to inspect the drive on your own bike given that it's maybe 6 years old and almost certainly seized solid if Luigi did the usual mandello rationing job with the grease pot. IMHO if I were faced with the same situation I'd get in there soonest to at least ensure the thing was working as it is designed to do before promulgating somewhat bizarre and whacko 'solutions' to a non-existant problem.
At least I could be sure my sig line wouldn't stand a chance of reading
Silver Y2K V11S
Mistral carbons, BMC filter, ElectroSport regulator, GEI relays ?, Odyssey battery, Corbin saddle, ConvertiBARS, Pro Grip 737, Ohlins forks from Cafe Sport, Penske shock, Pazzo levers, Napoleon mirrors, Brembo 7850 Calipers, Galfer brake lines, PCIII serial, TuneBoy AND locked solid rear drive with associated mangled driveshaft splines and screwed UJ!