900GTS build...

[Vacant Possession]

Hydraulic Clutch Conversion for 750's & 860 RH selector box engines - Part 2

The heatshrink arrived earlier in the week and apart from noticing that my slave cylinder was operating close to the end of it's travel, I was ready to go - but so busy I couldn't get near the ol' girl.

I made time this morning and elected to research how to persuade the slave cylinder to operate at the other end of its travel.

So I removed the clutch push rods and measured each one; Luckily I had a spare brand new set against which to measure. I worked out I'd get an extra 4mm length taking into account the mechanical advantage presented by the operating arm,; Also the arm would be at the other end of its travel and place the slave cylinder piston where I wanted it. Job done! I reassembled the clutch push rods with a load of grease, cleaned up the slightly shagged adjusting screw and gave it a shiny new bolt.

In my opinion, the pull rod from the slave cylinder needed a straight pull, hence I bought an extended operating arm and had it cut down & the angle modified to make the pull straight...

and as intended it doesn't look too different from standard...

It was time to a/ protect the frame, electrics & cables from a raw SS (Stainless Steel) brake piping and b/ to camouflage the SS such that it resembles a clutch cable, so I twist wrapped it...

I re-used the old fitting & olive - I wasn't too worried about pressure as it is only the clutch...

It was now time to tighten up the slave cylinder - which makes a really fine job of getting in the way and gave me an opportunity to get my grinder out (always a happy moment) and grind the crap out of a spanner I really don't like - Result? Finally a spanner I can use on the clutch nut! Now I have spanner love...

Time to give the twist wrapped SS pipe a heatshrink outer coating...

nip everything up and move back up to the master cylinder to start bleeding. The Frando master cylinder is well though out, with an upper bleed nipple which really helps get things started; As soon as it is drawing one can forget about the upper bleed nipple and concentrate on the lower bleed nipple. It doesn't take long except when one is a mucky pup like me, it took far longer to clear up my bleeding mess than it took to bleed the system .
Clutch operating arm relaxed, clutch engaged...

Clutch operating arm pulled, clutch disengaged...

For adjustment, the well thought out Frando master cylinder has a knurled knob which allows the pull of the lever to be adjusted - which also varies the pull of the slave cylinder between 9mm->12mm; The range is probably greater than that, but with my small hands I have no problems getting the slave cylinder to pull 12mm.

My greatest worry was that the pull wouldn't be right, but it is bang on! my SS pull with a non adjustable dogleg lever pulls the lever about 9mm at the crankcase.

So the conversion disengages the clutch further and the big question, how does it feel?

It feels really light, very smooth and I can't wait for my test ride but need to put the tank back on and do some work first (FX: Grrrr...!).

I'd say it is as light as any modern bike and feels 'well engineered'.

Oh! The clutch cable no longer exists and can't chafe the tachometer, which was my excuse for commencing this jape.

I am pleased, I hope you enjoyed reading it

 

[Nix]

Cool!

 

[Derek]

A very nice conversion and I'm happy to hear that it works very well but you could have saved yourself a lot of trouble if you'd bought a clutch line that was already fitted with a protective sleeve. It would look nicer than spiral wrap too. http://www.helperformance.com/create-your-custom-brake-hose.html

 

[Vacant Possession]

Ah yes! But I am a canny southerner!

I received the entire line & fittings gratis from DucatiPaddy along with another related purchase. For me, cannyness does not come naturally .

Thank you for the compliment, too.

 

[Derek]

As a canny Scot I can appreciate that

 

[MartinW]

Canny approval from Yorkshire as well

 

[Glawster]

Blimey Martin where have you been? 18 months in the slammer? Welcome back and what about the Darmah?

 

[Vacant Possession]

Looks like it's the GTS to the V Twin rally this year - the SS swinging arm is away having its new bushes reamed to match its new pin.

Luckily the GTS is pretty much ready to go - although I am almost bound to be left with a hot bike which won't start at some point .

I finally cracked the recalcitrant rev counter by buying a set of new gears. Whilst expensive, I could hardly get the rev counter cable in, so that problem is now sorted.

The rev counter needle is now rock solid & steady.

The engine is oil tight! It is dry as a bone and apart from one of the centre stand bolts coming loose and its hot starting tantrums, it is going well.

I now have sat nav which I hope will connect to my new Schuberth S2 with Bluetooth so I am hoping I won't get lost if I try a new creative route - as happened last year.

 

[BeePee]

I now have sat nav which I hope will connect to my new Schuberth S2 with Bluetooth so I am hoping I won't get lost if I try a new creative route - as happened last year.

Don't do it, while you're listening to music the @@@@ nav cuts in all the time telling you about every junction dodgy bend and each time you go over the speed limit, drives me nuts so I switched it off

 

[The GOAT]

Thread featured and bumped to bring it into the present day

 

[Vacant Possession]

Preparing for the Red Kite Rally Hay-On-Wye, Wales 20210917

After abandoning the SS at a rather late stage, I hooked the GTS out of the garage; I wanted to:

• change the oil & filter
• inspect the internal magnets for foreign material
• check the brakes
• change the cast FPS wheels for spoked wheels with new Michelin Pilot's
• set up the carbs

Both the SS & GTS have fully rebuilt engines, have 40% uprated oil pumps, full flow oil filtering systems and run on fully synthetic modern oil and contain three magnets each; one on the dipstick, one in the gauze filter and one under the oil filter.

The first thing I do is inspect these magnets and the good news is the GTS magnets were not far off pristine.

Whilst setting up the carbs, I found the adjusters on the top of the carbs were not long enough to achieve the correct settings. Purely by chance I had ordered an uneeded long set for the SS; with that done, I was able to synchronise the carbs. Whilst I was at it, I had bought a set of fibre 32mm spacers using 'O' rings to replace the dreadful plastic/metal gaskets installed by Ducati. They are like the Malossi ones available for 40mm carbs:

but made of bonded fibre instead.

It retains it's valve springs, is running standard air filters, standard cams and standard carbs as I didn't want to change the characteristics of the engine. I does have unleaded friendly exhaust valve seats.

I hadn't realised it, but I had solved a long term gripe I have had with the GTS, which was poor starting, idling and regular stalling. If you run a bevel, I can't recommend enough both the Malossi parts above and the part I used for the GTS. The GTS has turned into a reliable starter, never stalling and running sweetly. What a difference! It looks like one or both of the ancient and flawed gaskets was leaking, leaning off the mixture.

I can't describe how well the bike is running, it's really quite excellent, a mid range monster (and it feels like one of those) on which you can short shift and enjoy.

The GTS is using Silent Hektik electronic ignition, Shindengen series regulator, Exide lithium battery. With no starter motor it is really quite light and is very nimble. If you offered me a brand new 900GTS now I'd take mine every day of the week. It is simpler better, more reliable, safer and probably quicker than it's original form as it's lighter.

Fitting the Smiths instruments wasn't an option as this was the day before I was due to leave; whilst I am going to fit the Smiths instruments to the GTS, it will be even harder than the SS as there is very little room in what looks like a dash on the GTS but really isn't. It's quite an odd setup.

Anyway, without further ado here is the bike ready to go without tank bag.

The red stand is because the GTS (and Darmah's) have the foot hook in a slightly different position to the SS - and it's much weaker. They tend to twist-snap which is what happened to mine. I have bought a new one and welded in fillets to solve this poor design. The stand you are looking at is off my SS lightweight Verlicchi racing frame. That will be the subject of another build.

 

[Noobie]

I do like that

 

[Hugo Magnus]

What dedication and perseverance. I take my hat off to you

 

[SHarper]

Puts me in mind of a banoffee pie, the colours not my cup of tea, but I applaud the work…

 

[Vacant Possession]

Upgrading the instruments, skipping the speedo & rev counter drives...

I have never liked the rev counter drive on bevels, it truly is in my opinion a carbunkle and even with new gears & seals, brings with it a very fine but annoying weep or mist, almost invisible but nevertheless there. Likewise the speedo drive which bent it's drive tang and scored my lovely wire wheel casting. Let's not begin to discuss the accuracy of these Veglia's. And I was 'done' for speeding on the way home to rub it in.

In response, I bought a set of Koso instruments: a speedo, GPS sensor & rev counter.

It's not a perfect solution and there is a lesson here - download the specifications & installation instructions before purchase, and from this you might surmise that I didn't. A big tick mark for you.

I already have a Smiths set for the SS and am quite well advanced fitting them and am acquainted with their electrical installation requirements. The Smith's instruments are 82mm which makes them a tight fit. With the SS I have bought a new dash and modified it to suit, but that isn't quite so easy with the GTS as the mounting bracket is steel and does not lend itself to that sort of mod. That's my main excuse for plumping with the Koso's.

I didn't need or want the extra idiot lights present in the Koso speedo, but decided to enliven them anyway.

So what do you get?

Here is the Koso GPS receiver, as you can see it has a receiver *and* an antenna.

This is different from the V3 GPS receiver recommended for Smith's, which is an integrated unit containg receiver & antenna - although it is a little bulkier than the Koso components.
The Koso antenna is supposed to be mounted in clear view of the sky, that might sound easy on a bike but the best I could come up with was a new bracket I fabricated which mounts to the brake splitter mount above the bottom yoke. It has been filed, but I didn't bother polishing it; the GPS receiver comes with a self adhesive base and my bracket supplements this with tie wraps.

The speedo comes with a load of bare wires and an interim plug; I say interim because the GPS unit comes with an adapter cable to convert speedo to the type of socket adopted by the GPS unit. Needless to say, that was chopped up and the interim connector scrapped.

I didn't like the thin wires, as they wouldn't be a good match for the Molex connectors I intended on using. These were sourced as usual from the ace Kojaycat site. The Koso cable was chopped, soldered, heatshrunk & rejoined and terminated in initially a 6 way Molex, then finally a 3 way. More on that in a minute.

By this time I had read the documentation (but had still missed a few things ) so knew that the Koso dials both require a separate straight-from-the-battery +ve supply *and* a switched supply from the ignition; they simply won't work properly if you join them up.

I wanted it fused and didn't want to fiddle with the ignition switch, so chose to make a small mod to the sub loom that feeds the ignition switch & dash; it lends itself well to this.
The 900GTS has a very different loom to the 860GTS, but I have never seen a proper 900GTS wiring diagram; the 900GTS loom is a lot like the Darmah loom but butchered to interface with the 900GTS dash. Nevertheless, the 860GTS is somehwere to start and I know the MHR/SS/Darmah era looms quite well.

I added a new ground/-ve cable direct to the frame and a female bullet connector the dash end, and created a mini loom to link the instuments to ignition +ve, battery +ve & -ve.

Supplying the Koso speedometer idiot lights for high beam & indicator (the Koso requires both L & R) involved modifying the dash, which after 44 years isn't exactly in perfect condition. I am not the first to have 'had a go' at the PCB . This gives us an extra sub loom coming out of the dash.

The sub-loom from the ignition switch & dash as I have already mentioned interfaces with the main loom, that part is under the tank. However, turning the handlebars moves this loom and as many already know, soldered copper wires that are repeatedly bent snap, in fairly short order, I could see this happening to the loom wher it meets the dash so I slotted the headlamp bracket to take a tie wrap and stopped the loom from pivoting on the dash wires.

Once the intruments are fitted, this is nigh on ivisible but I left the tie tail visible on purpose so I can tension it up when it has had time to settle. You can just see the supporting tie wrap & tail in this image.

Going back to the Koso wiring, there is no 'lights' cable/connector; i.e., the instrument lights are always on.
The logic on the neutral connector is flipped - the Koso expects the neutral line to be taken to ground and I couldn't be bothered to flip it so the neutral light in the Koso is not connected. All I have for neutral in the dash is floating (N/C) or +ve.
So going back to the dash sub-loom, I no longer needed the neutral wire; so was able to use a three way Molex for indicator L&R and high beam, and dump the rather bulky six way connector.
Everyone needs a break, so I nipped out with the old stuff fitted; and this is where this post ends.

To be continued...

 

[Vacant Possession]

Upgrading the instruments, skipping the speedo & rev counter drives

So this has been a little bit harder than I expected, but let's get to the good bits.

The keen eyed will have seen some yellow/black wires with heat shrink applied and tied up with a tie wrap. They are the original instrument light cables, tied up safely, insulated and out of harms way.

As usual, I can take it all off and put it back to the standard nonsense should I want a leaky less accurate setup with high speed rotating cables churning around and messing up the look of the bike..

So here is the complete speedo kit ready for attachment, along with a few very useful tools: note the Molex pin removers, these are quite expensive but work really well.

Fitted up to the bike, it's starting to look like it might come together...

With the headlight on, you can see the placement of the receiver; it's sitting on adhesive foam pads for a bit of protection against vibration.

Finally after what has been quite a lot of work, you can see two reasons why I did this; firstly take a look at the nice wheel spacer where there once was the abomination known as the speedo drive which scored my lovely hub. I am not going to bother with a euphemism for this relic of a Victorian worm drive that should have stayed on the traction engine upon which it was conceived:

...and I have the same disdain for the worm drive this lovely cover replaced too; I found it on eBay and I haven't yet polished out the ding.

Finally, the Grand Finale, the reveal - Ta Da!

I think they look pretty good, rather nice. Look, no cables!

The ruined paint on the frame downtube is what ethanol does to powder coated frames, my fuel tap leaked over Christmas . No worries, it's called an opportunity to give the bike a makeover as soon as I can get the SS back on the road with its new wire wheels (for safety, I love the mags), Smith's GPS speedo & Smith's electronic tachometer.

Tachometer
I haven't said much about the rev counter as as soon as I had clocked the supply requirements for the speedo, the same applied to the rev counter which left me with one wire to sort out from one of the coils to the tacho. I modified the tacho so that it connected with another three way Molex, plugged it all together and it worked first time. So not much to say about the tachometer other than I like it.

Edit: The Koso has a setting for whether the signal is +ve or -ve. My pickup is on the -ve side of the coil and is switched by the electronic ignition unit, and the +ve side of the coil is straight to the battery (via the ignition switch). If this setting isn't set correctly for the Koso, the tachometer remains implacably still. It's an easy setting to change so if your new Koso doesn't work, try this setting. Some electronic ignitions switch the +ve side of the coil and some like my Silent Hektik switch the -ve.

Software
Wrapping up, I would be remiss not to mention how easy the Koso's are to set up. I know it's obvious, but it's important to read the destructions. Entering the correct parameters in to the speedo to match the GPS unit is easy to mess up (the correct settings are with the GPS instructions); the speedo comes with a rather nasty super clunker of a magnetic sensor which wasn't going anywhere near my bike.

To set the Koso's up, they both have identical small push buttons at the front which are accessible. I wouldn't try it whilst riding, but they are quite easy to get at. There is a select button and an adjust button; on the speedo I wouldn't rush it as if you are a little too quick, you have to go all the way round again through all of the options. But fair enough, it is simple and it does work.

Nice features are you get a clock and you can enter your true mileage; I really wanted to do this as my bike achieved a pretty high mileage (IMHO) for that time of well over 60K before she was finally laid to rest. Let's not forget, this is the Dark Side Of The Moon bike, which arrived with a rusty metallic black paint job & DSOTM prism sprayed onto the tank. So very 70's . I love it.

 

[general_piffle]

What a fantastic job! This thread is almost entirely responsible for making me want a late 70s 900 GTS. Damn it!