Ducati Electrics
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storm42
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Ah, this is where the internet failed me, when I first looked at this, I miss counted the poles as 15 and I considered 3 phase. I counted the wire off the poles at 16 turns per pole, I figured that somebody has worked out that to get the required voltage
out of the alternator then 240 turns of wire round 1 pole was needed and as there are 15 poles then 16 on each would meet that spec. (240 / 15 = 16)
I guessed that to get the same from 5 poles then there would need to be 48 turns on each pole to get the same voltage, add 2 more sets of 5 and there would more current for the same voltage.
I tried to research this theory and failed, I then realised that there were only 14 poles so it all became a mute point. I did realise that to fit 48 turns of wire on those poles, I would have to have used much thinner wire and a lot more work getting it on if my thinking was right about more turns being needed. Maybe someone could enlighten me. Incidentally, if it is right, then 12 poles would need 60 turns, even thinner wire then.
Sometimes I overthink things.
storm42
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I have three Ducati beveldrives including two SD's. (one + 80 rwhp, +9000 rpm, 220 kmh (stock being around 52 rwhp on the post 1980 big port and maybe 190 kmh flat out)
The only electrical failure I ever had was a R/R so lucky perhaps.
They are still (with uprated suspension) a very usable bike and will lope along all day any distance ( but 100 kms / 60 miles to get the engine to temperature)
The engine should turn over with no concern (the uprated starter sprag clutch (916 perhaps) is probably a good idea) due to the substantial starter ratio.
The starter intermediate chain must in good condition.
With careful detail to building they are very reliable in general even in modified form.
I still remember my first engine refresh in the mid 1980's, the factory manual said to shim the crankshaft to zero end float, I decided with angular contact bearings to go to zero then add 003" preload.
Many years later talking to a factory mechanic he thought that a good guess with it being around 0.1mm / 004".
Life was easier when you had no idea of what you were doing so anything went and my motto was 'what could possibly go wrong... who knows.
Beveldrives are very expensive to buy these days, even more so to rebuild due to the over inflated parts prices used as ransom.
The only electrical failure I ever had was a R/R so lucky perhaps.
They are still (with uprated suspension) a very usable bike and will lope along all day any distance ( but 100 kms / 60 miles to get the engine to temperature)
The engine should turn over with no concern (the uprated starter sprag clutch (916 perhaps) is probably a good idea) due to the substantial starter ratio.
The starter intermediate chain must in good condition.
With careful detail to building they are very reliable in general even in modified form.
I still remember my first engine refresh in the mid 1980's, the factory manual said to shim the crankshaft to zero end float, I decided with angular contact bearings to go to zero then add 003" preload.
Many years later talking to a factory mechanic he thought that a good guess with it being around 0.1mm / 004".
Life was easier when you had no idea of what you were doing so anything went and my motto was 'what could possibly go wrong... who knows.
Beveldrives are very expensive to buy these days, even more so to rebuild due to the over inflated parts prices used as ransom.
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Hello Ralph,
Report on Darmah starter motor,
New brushes, turn the comutator in the lathe for a light skim, re thread the stator winding / brush screw mount. Clean and grease all the shims and bushes....
Re install,,, Runs like a champion now.
Lots of hours and very fiddly but made a big difference.
Now to get the front carb to work better than it does.
Engine goes like a dog shot in the arse from half throttle to full throttle, time will get it running right from off idle to 1/3rd throttle.
Regards
Graeme
Report on Darmah starter motor,
New brushes, turn the comutator in the lathe for a light skim, re thread the stator winding / brush screw mount. Clean and grease all the shims and bushes....
Re install,,, Runs like a champion now.
Lots of hours and very fiddly but made a big difference.
Now to get the front carb to work better than it does.
Engine goes like a dog shot in the arse from half throttle to full throttle, time will get it running right from off idle to 1/3rd throttle.
Regards
Graeme
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Time Warp,
True about Bevel twin stupid prices,
eg, 450 1974 Desmo disc brake single has the same rubber grommets as Darmah to mount the side covers.
Why are the Darmah grommets 1/3 more expensive than the 450 single grommets ? Same part number,,,,,,,
Graeme
True about Bevel twin stupid prices,
eg, 450 1974 Desmo disc brake single has the same rubber grommets as Darmah to mount the side covers.
Why are the Darmah grommets 1/3 more expensive than the 450 single grommets ? Same part number,,,,,,,
Graeme
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Is it an Italian bike thread now.
You might want to check the slides (stock PHF 32's) which changed over the production, the earlier Darmah's have slides no longer available new and might have been a leaner cutaway. Later might have been a 70/2.
I changed carburetors over the years, PHF 32's to Mallosi Dellorto PHM 40's in the later 1980's then FCR 41's in the later 1990's.
The original 32's mothballed in the mid/later 1980's.
Those original 32's from my 81 SD are now on my 1973 Moto Guzzi Eldorado.
Diluted DuraGloss 853 sprayed on and run under the tap the moment white foam started to appear.
Done a few times.
A set of manifolds for Dellorto VHB30's (larger OD spigot than 29's)
Sleeves machined to suit the PHF 32's spigot ID.
Dual gaskets taper machined to 2mm to 3mm to angle the carburetors outward slightly so they were vertical and missed the gearbox.
Threaded adapters machined to mate up to the stock airbox boot and look as stock as possible.
70 degree cable guides, custom cables (via Conwire in Sydney) and custom jumbo Acetyl cable splitter for low friction action.
I had hoped to get my Ducati's (and two TL1000S's) out of storage in 2022 but it does not look promising.
You might want to check the slides (stock PHF 32's) which changed over the production, the earlier Darmah's have slides no longer available new and might have been a leaner cutaway. Later might have been a 70/2.
I changed carburetors over the years, PHF 32's to Mallosi Dellorto PHM 40's in the later 1980's then FCR 41's in the later 1990's.
The original 32's mothballed in the mid/later 1980's.
Those original 32's from my 81 SD are now on my 1973 Moto Guzzi Eldorado.
Diluted DuraGloss 853 sprayed on and run under the tap the moment white foam started to appear.
Done a few times.
A set of manifolds for Dellorto VHB30's (larger OD spigot than 29's)
Sleeves machined to suit the PHF 32's spigot ID.
Dual gaskets taper machined to 2mm to 3mm to angle the carburetors outward slightly so they were vertical and missed the gearbox.
Threaded adapters machined to mate up to the stock airbox boot and look as stock as possible.
70 degree cable guides, custom cables (via Conwire in Sydney) and custom jumbo Acetyl cable splitter for low friction action.
I had hoped to get my Ducati's (and two TL1000S's) out of storage in 2022 but it does not look promising.
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I payed $2500 for my 1973 750 GT, a reproduction dash housing cost $450, these days a complete basket case might be $16000+.
I have one more NOS 1978 900SS clutch cover left if anyone was looking for one (The last one went to Belgium)
I have one more NOS 1978 900SS clutch cover left if anyone was looking for one (The last one went to Belgium)
SteveBorland
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Yes, bevel prices are astounding. I bought a new headlight switch (the tin box from Aprilia) for a very small amount, it came from a Lambretta shop and was something like 1/10 the price asked by a Ducati specialist.
There's a bloke in Oz who rebuilds the headlight for the bevels - separates the glass lens, resilvers the reflector and reassembles it, costs around $1000 Aust. as far as I remember. A NOS light (remember this is just the glass) was around $2000.....
My original is sitting in a box now, there's a generic H4 unit on the bike
storm42
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I bet the more powerful one is good fun. I went to work on mine on Wednesday, before I set off, I checked the tire pressures there was 6 psi in the front and 20 in the back, strange how the bike felt ok as the speed came up, the handling was only heavy at low speed. Anyway that will teach me to check the pressures before a ride.
With the correct tire pressure the bike is very nice, it is a good job I didn't have one before I got the Norton, I may never had bought one. The clutch slip is getting worse.
storm42
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Good news, always worth having a play.
storm42
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Nice job, that Duragloss works well, that carb looks new.
storm42
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I bought this bike with a view to making a bit of money, I am a bit pissed it rides so well. I will probably sell it when it is sorted but I may try and find a cheap Monster. Or I could bring it to Spa next year.Yes, bevel prices are astounding. I bought a new headlight switch (the tin box from Aprilia) for a very small amount, it came from a Lambretta shop and was something like 1/10 the price asked by a Ducati specialist.
There's a bloke in Oz who rebuilds the headlight for the bevels - separates the glass lens, resilvers the reflector and reassembles it, costs around $1000 Aust. as far as I remember. A NOS light (remember this is just the glass) was around $2000.....
My original is sitting in a box now, there's a generic H4 unit on the bike
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The later Surflex clutch plates have narrow band friction linings which help with clutch slip. (They were wide prior to that)
It depends which year it is, the later box tail models with the eccentric swing arm pivots adjusters and rear axle adjusters allow the swing arm angle to be increased a little within the upper chain run limitations.
Bridgestone BT46's would suit them these days.
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Time Warp,
Are you saying the new 70/2 slides aren't the same cut away angle as the old 70/2 slides ?
I know I had to alter the bottom of the new slid to sit on the idle speed adjuster screw .
Eurocarb in UK makes note of this.
The front carb on the basket case had a 60/3 slide, late model float bowl nut etc, and late model idle mixture screw with the long nose.
Not knowing what had been done by previous owner /s, I went to original carb spec parts except for 262 atomisers instead of 265
The rear was as per original, so just cleaned up.
The front is the issue, and seems to be running lean.
Graeme
Are you saying the new 70/2 slides aren't the same cut away angle as the old 70/2 slides ?
I know I had to alter the bottom of the new slid to sit on the idle speed adjuster screw .
Eurocarb in UK makes note of this.
The front carb on the basket case had a 60/3 slide, late model float bowl nut etc, and late model idle mixture screw with the long nose.
Not knowing what had been done by previous owner /s, I went to original carb spec parts except for 262 atomisers instead of 265
The rear was as per original, so just cleaned up.
The front is the issue, and seems to be running lean.
Graeme
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I would have thought 265's better in the PHF 32's.
The new 70/2 slides are the same as the originals (Maybe $150 each now) the slide underside is different as is perhaps the venturi under the slide in the carburetor itself so not interchangeable. (as you mentioned)
I think my 1977 SD (#559) had 60/3's (The last number being the pump cam operation) my 1981 70/2's and never a hiccup and could get 60 mpg.
The needle is important and will look it up.
It might depend on what year the bike is, whale tail SD's have the narrow spaced inlet manifold studs and ports. (iirc)
The new 70/2 slides are the same as the originals (Maybe $150 each now) the slide underside is different as is perhaps the venturi under the slide in the carburetor itself so not interchangeable. (as you mentioned)
I think my 1977 SD (#559) had 60/3's (The last number being the pump cam operation) my 1981 70/2's and never a hiccup and could get 60 mpg.
The needle is important and will look it up.
It might depend on what year the bike is, whale tail SD's have the narrow spaced inlet manifold studs and ports. (iirc)
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Yes that is the last digits in the engine number.
I only bought it as a complete and running parts bike back in the 1990's.
If yours still has its original Campagnolo magnesium wheels they would need careful checking for cracks.
If you have changed the coils removal of the ballasts is normal.
I only bought it as a complete and running parts bike back in the 1990's.
If yours still has its original Campagnolo magnesium wheels they would need careful checking for cracks.
If you have changed the coils removal of the ballasts is normal.