(photo bike by maryport globe and bin) @LDP its as well i'm not superstitious ... owner 13 enjoying riding and maintaining the bike. i'll take it for MOT, once some bearings replaced. 900(?) with clean plugs, it feels similar to the Guzzi. wondering if the bike is just a little off colour, or something more. tempted to remove a head and measure. looking like the base gasket on both cylinders is leaking, so i'll wait until that task is undertaken. maybe do a compression test, once other work complete. hopefully another forum member will explain what the possibilities are ... could a 750 have a dry clutch? do 750 heads fit the 900 cylinders? that sort of thing. edit 20/5. found https://www.ducatiforum.co.uk/threads/900-cylinder-heads.46232/ to look at later key difficult to remove from switch needed some jiggling of the key, to switch on - and again to remove looks twisted photo better after squashing flat in vice. could then see where it was bent. a few tweaks and it worked smoothly in the lock. photo spare key doesnt fit lock. photo after some work with needle and warding files photo screws securing fairing one lost on ride from woking to cumbria. secured with tiewraps. photo new rawl well nuts fitted and others checked/replaced. some perished. the two at front fasteners (with the 'cotton reel' spacers) replaced. new washer machined from acetal. (puzzled why the photos didnt upload/snipped image insert. something to do another day)
Seat Fiddly to remove noticed that the seat cover is worn through, where it touches bodywork. key doesn't enter lock completely - but unlocks. tank looks to be as far forward as it goes. checked lock alignment loop on seat, sits in catch, so lock position ok. front of seat tight up against tank. seat lugs trimmed by previous owner (Paul?). decided to trim seat, to fit easier. maybe original cover? 1997 peeled back the cover marked a couple mm to trim.
employed a wood rasp, to trim back the seat tried on bike marked and trimmed a little more rounded the edge, scraping plastic with edge of knife blade glued the splits, in cover glued cover back in position tried seat on bike. clicked readily into position - and removed with ease. seat lock to remove and sort another day.
Hello! Very pleased to see my old 900 being looked after, overall, I loved that bike and it only got sold due to my move abroad. Now, with regards to the possibility of the bike being a 750 with 900 heads, I really doubt it. I took the bike to Ducati London and had them inspecting the bike as I was going the route to try and have a second inspection with DVLA in order to get an age related plate. They confirming this is a 900 and possibly, with real original lines too due to internal tolerances. By the way, there is a white 900 frame with V5 for sale for something like 200£, should you wish to transfer everything and drop the Q plate. Having said that, good luck with the fiddling and feel free to ask
thanks Joe. delighted to have the bike. would like to have bought both from you. sadly life got in the way, and i was away from internet for a while. what progress made with your 851? utterly charming ride. both across to woking (avoiding motorways) - and then up to cumbria. on the journey up (avoiding motorways) even crossing Manchester was reasonable. trickles along happily. lovely to balance and not too cramped. on A and B roads, it steers beautifully. forks dont appear to do much, though ... rather firm. "Now, with regards to the possibility of the bike being a 750 with 900 heads, I really doubt it." i was thinking maybe a 750, with dry clutch. was there such a thing? if not, possibly a 900 with 750 heads? can the heads be identified without removing them? did the london dealer remove the heads, and measure the valves and bores please, Joe? "with real original lines too due to internal tolerances." sorry i dont understand what you mean, @Joe Goodson. please explain another way. "By the way, there is a white 900 frame with V5 for sale for something like 200£" one near milton keynes(?) for circa £480. please share a link for the £200 one @Joe Goodson. having said that, the Q is now part of its history. do you recall who owned the bike before Paul, please? lovely to hear from you Joe. David
brackets at bottom of fairing considered making a copy in stainless steel. thinking about another issue (mirrors), i recalled stumbling across a youtube video. one of the improvements shown being mirror braces. gave up searching youtube and searched on this forum https://www.ducatiforum.co.uk/threads/modified-superlight-mkv-recommisioning.78104/. copied that idea (one piece 'bracket') instead - using the stainless I had. thanks Max.
I think there were some 750s with a dry clutch though only a 5 speed gearbox. There were different versions of 900 head, do the heads have a stamp: V, V2, W etc. by the spark plug hole? as per this pic; As for it being a 750 with 900 heads, I don't think the stud spacing is the same though someone more knowledgeable may confirm? Do the cylinders have the external oil return lines to the crankcase? If there is oil leaking at the base of the cylinder, it is possible there is a broken cylinder head stud? quite common on early 900 engines, try turning the head nuts with a spanner.
excellent thanks - i'll have a closer look one evening. i vaguely recall there being something where the v2 is shown in photo. reminded me of cross hatching/something having been obliterated. i've not counted the gears. easily done though - thanks. external oil lines ... i think so. i'll check and photo, so you can advise further. there is oil at base of cylinder. thanks for tip re checking head studs.
looked for 'V' marking on the cylinder heads. the marking has been obliterated, on both @Dukedesmo (vertical cylinder) (horizontal cylinder) edit 28 may. 6 gears. i was counting 5. switched on ignition, to see the neutral light. kept rocking the bike forward and backward, until i could see the neutral light when i lifted lever from bottom gear. its 6 gears. from when i rode it, gear selection has a idiosyncrasy. changing down, it sometimes feels like its in bottom gear, when its in second. as if the selector hasnt 'reset'. it has external oil lines @Dukedesmo put a spanner, on the nuts securing each head. the screws are all tight. spotted something odd though. looks like the base gasket, on front cylinder (horizontal) sticking out of the joint.
front wheel buckled - and not central, between forks last mot (may 2022) had an advisory, on wheel bearings. couldnt feel any play, so removed brake pads. wheel still dragging on something. looking closer, realised it was the right hand disc, rubbing on the caliper. left disc, close to rubbing the caliper. took off the calipers and measured. measurements (right side approx 23.5mm) chrome on stanchions pitted, but not compressed forks enough to pass over the pitting/blisters. 'talking' with @CAT3 i have decided what to do about the forks. (left side approx 16.4mm) felt a small amount of play in the bearings, for approx 1/4 of turn of the wheel. spun the wheel and realised its buckled. i didnt feel it when riding - but suspect it would have been quite a heavy impact, to ding/dent the rim. to be trued before taking for mot https://www.youtube.com/shorts/q3mrtoXuU7M removed the wheel ... noting that one of four axle pinch screws, was loose - and the other three, finger tight. took wheel to Chris at cockermouth, for tyre to be removed. hopefully wheel can be trued and isnt cracked/otherwise damaged. removed the discs and packed the wheel ready for collection tuesday. off to motoliner https://www.motoliner.com/motorcycle-wheel-straightening.php casing of speedo drive cracked. maybe cosmetic only, and the rain cant get in? doesnt look like it goes all the way through though what are forum members opinions please? theres one for 25mm spindle on ebay uk. i see one sold in usa recently. £95 shipped. the £50 item was in uk. new 'old stock'. said to be cracked. "Some minor shrinkage cracks in edge of plastic body, does not effect unit (see photos)." the uk breakers contacted dont have one for a 20mm spindle. (front wheel spindle) (spacer in left fork leg) (spacer in left fork leg, flange thickness) (in the exploded view, the flange isnt obvious) reassembled with a spare wheel (left the speedo drive off) (right side) (left side) maybe the spindle was working its way out of the fork legs - towards the right side? perhaps bike has some parts off another model. are there different spacers, spindles (20mm) and speedo drives (20mm) available, please? maybe i simply need to machine a spacer, with a different flange thickness.
removing discs from front wheel some of the screws undid with a simple allen key. (debris could be powdercoat?) a few needed heat and impact driver. (thread on screw, appears filled with white) i'll clean face that is in contact with the disc - and chamfer holes/remove white from where first thread removed - before refitting the disc. i havent seen white loctite before. dont think its boss white (plumbing sealant). perhaps its powdercoat. a little copperslip visible on some of the screws. (debris in hole) (cleaned the threads with m8 x 1.25 tap)
thanks for advice @Sev. "Before you go machining anything the spacer sits with the top hat outboard. There's a recess in the fork leg to accept it." yes, spotted recess in left fork leg. (photo to add tomorrow) outboard(?) ... maybe that's the problem @Sev . recess is in the wheel side (inboard), of the leg. so spacer had been fitted from the wheel side. i didnt check, before refitting it that way. interesting. if the legs were turned around, i dont think parts would fit ... clamp screws would be on back of leg too - but happy to look tomorrow. maybe there is a deeper recess (for rim of the hat) in outside of leg. as is, the spacer (in fork leg) appears to rely on the clamp/pinch screws .... nothing else to keep it in correct location. i was looking for a (semi-circular) recess in the spacer (or similar), that a pinch screw could pass through, so locking the spacer in place (side-to-side). as is, its only clamping the leg onto the spacer - with the pinch screws - that prevent the spacer 'walking' out of the leg. as i commented, the clamp screws were loose/finger tight. entering the spacer from outside, so that the rim/flange is against the outside of the leg, would constrain both spindle and spacer. i agree with you, that makes more sense than how it was assembled. hopefully its that simple to resolve. i wonder what similar mistakes could have been made elsewhere, when bike last rebuilt/worked on? more importantly, how may i best find/recognise them. the tyres look fairly new - and having 'talked' with previous owner, were fitted shortly before he bought the bike. perhaps tire fitter forgot to tighten the clamp screws, when wheel was refitted. i didnt think to check, before riding the bike home. i will next time. reminds me of something else. on the ride from Folkstone to Woking, the head bearings felt loose. i stopped to check. top nut was loose. tightened it with fingers (repeatedly), until i found a Halfords to buy a spanner. other than not having been torqued to spec, what are your thoughts on likely causes, please? its an aluminium nut - perhaps distorted, or threads worn? i havent looked at a diagram/exploded view, perhaps a part is missing? last mot mentioned play in the head bearings. i'll take apart and look for brinelling/grease/adjust/replace before taking it for mot. "The spacer should have the thread for the axle in it." it does - at the side away from the wheel. so sliding fit on spindle, on the flange (rim of top hat) side of the bush. (photo to add tomorrow) "The axle forms the RHS spacer and the speedo drive forms the LHS spacer and it all pulls up and torques on to the LHS fork leg." yes, i see that the shoulder on the spindle, sets the wheel position, on the right hand side. given that the axle clamp screws were loose, my suspicion (as noted), is that the spindle was on its way out of the fork legs. from stein-dinse though it doesnt show the part number thats on the speedo drive. where could i look-up part number that appears on the part, please? is there a better parts list that i could refer to? is there a record elsewhere on this forum (or somewhere that you could suggest, i look up) of how long the bush/spacer in the speedo drive should be? length of spacer (between bearings) in the wheel? distance between fork tubes, measured at the yokes? please @Sev ? "Do your spokes show signed of buckling?" not that's obvious. how would you check, please? "have you checked the discs?" yes. with a needle, nearly touching the face that the disc is fixed to. minimal deviation seen, when on the wheel, on the bike. had there been a marked wobble, i would have considered making a clamp, to hold a dial gauge on the fork leg ... or checked to see whether the lathe is big enough (dont think it is, sadly), to set disc up on a face plate, and measure with a dial gauge. on a surface plate, disc sat on blocks, checked with a height gauge - the disc is flat. "Have you checked for fork misalignment and length?" yes, basic checks. both flush with top yoke. so dropped further through the yoke that i've seen in photos - is that normal? with the wheel out the way - front of bike supported under the yoke - the hole in each fork leg lines up. spindle readily slides in. i didnt need to push up on a leg to fit the spindle, for example. worth another look tomorrow though - now i have a checklist of what to look for. thanks. no visually obvious twist, between fork legs ... when i put two 'parallels' across the forks. what other checks recommended, please? "Your discs are misaligned and if this is the case then it means irrespective of what your wheel rim is doing, in the worst case your hub is out of true , and for a hub to misalign to that sort of deviation at the disc then structurally you've got bigger things to worry about - so i'd be certain before you met motoliner loose on your wallet." discs appeared offset (initially viewed relative to the caliper), side-to-side. the hub doesnt appear to be out of true. with a needle held in a bit of plasticine (stuck to forks), the hub appears true, both side-to-side and radial. whether its in the middle of the rim, i dont know. hadnt thought to check. good suggestion Sev. where the rim looks reasonably true, i could rest a straight edge (across diameter) and measure with calipers, to the disc mounting face. if there are better/easier/more reliable checks, please describe them @Sev "Check the discs" as above, the discs appear ok. can be checked again though - what's recommended procedure, please? "check the forks and yokes - straightens and also length as you won't be the first and last bloke to have shorter internals in one leg than the other." as above checks, they appear straight and same length, when allowed to 'hang free'. what variation considered acceptable? i could take the legs out and roll the stanchions on a plate/support in v-blocks and measure deviation when the tube rotated. could also take them apart and hold internals side-by-side. "I'm not convinced because your measurements for disc deviation don't seem to align so one side is affected more than the other, so I'd be looking at discs and forks first." possibly. my thoughts being that clearance at left disc-to-caliper appeared minimal, so maybe not much variation side-to-side. once calipers (and speedo drive) removed, and spacer appeared seated correctly in the left leg, the difference was less. that said, i didnt tighten-to-torque. and without the speedo drive in place, the wheel could have moved away from the shoulder on the right hand side. i didnt push-hold wheel against the RHS shoulder on spindle. i'll know to next time - thanks for prompt. which means ... measurements could be misleading/complete nonsense. did push the spacer firmly into recess in the fork leg. less of the flange stood proud of the leg. i recognise thats only part of the requirements though. having read your explanation, i'll certainly put it together and measure again. thanks for the prompt. "Check the barrel and hub alignment and hub runout by using a known good datum ie the disc mounting face." what's the barrel, please? hub checked as described in my reply above. looks like a fine day tomorrow, so hopefully i'll have time, to have another look at the bike. "Check everything and then decide what you need to send away or spend money on." very sensible advice @Sev , thanks for the time taken and detail provided in your reply. its apparent that your knowledge of both the bikes and problem solving are extensive. thats much appreciated. i'm enjoying learning about both. its also a useful 'distraction'/alternative point of focus-attention sometimes.
"Ok, so my mistake, the top hat sits inboard on the left hand fork leg, not outboard as I said- i went and had a look at mine!" thanks for checking @Sev. especially since its late in the evening. "So.. are you in Cumbria or woking?" cumbria. lived in woking (horsell) for many years youve given clear and concise instructions. i'll try and make time tomorrow, to follow them and report back.
measuring the front wheel "In wheel design the barrel is the hoop that the wheel accepts the tire. The hub and spokes are separate elements." "get that wheel on a nice flat surface (surface plate would be nice) and use the v blocks to hold the wheel on the disk mounting face." " ... see whether its nice and consistent around the rim to table surface." summary measurements
measuring offset of the front brake discs "... Same goes with the discs. Mounting face is datum." "The discs on a road bike will be 10mm offset to outboard face from datum face as they are 5mm rotors. (7.5mm offset to "centreline), and as semi floating discs you should be able to not have inconsistent results due to disc float." disc on surface plate. surface plate against disc-to-wheel mounting face. (disc that was on right (RHS) side of wheel.) feels flat, with no obvious wobble. turning disc other way up, a little powdercoat adheres to the mounting face. scraped the powdercoat off, with a piece of brass rod. (cleaning powdercoat off the disc mounting face.) after vacuuming up the dust, and a rub with scotchbrite. (disc that was on left (LHS) side of wheel.) with disc-to-wheel mounting face on surface plate, the disc wobbles - when pressed down. turning the disc the other side up, there is more powdercoat, adhering to the mounting face. after cleaning off the powdercoat, the disc-to-wheel mounting face, sits flat on the surface plate - without wobble. checking with finger nail, there isnt a step, where the gold colour ends. (zero height gauge on the surface plate.) from surface plate, to unworn part of disc is approximately 10mm. measured at another position, the value was 9.7mm. dimension from surface plate to carrier, (and also to the disc) was 9.7mm. checked at a couple of different locations. the disc carrier thickness, is typically 4.1mm (including the gold coloured coating). left disc was very similar
"Something else to try: Put the axle back into the wheel and check there's no slop. wheel out of the bike. Doesn't have to be tightened up at all. All you're checking for is that there's no movement in the bearings or the axle once inserted." axle is a sliding fit in the bearings @Sev. no slop. there is a little play in the bearings. my impression is that its very slightly more, than when wheel is installed in the bike.
