900GTS build...

Help! Not sure about how to assemble the horizontal cylinder airbox...

Now the electrics are all working, the reasons for not mounting the tank are getting more invalid with every task completed.

The front airbox has an input for the crankcase breather and I am not sure how it mounts, if anyone has done this recently (Derek ;-) ) I will be very grateful if you will let me know how it is assembled; It all seems a bit jury rigged to me.

i am not sure whether part #: 0960.91.735 sits inside the airbox or outside...
AirFilterParts.jpg


The diagram is close but the way my airbox attaches to the frame is slightly different.

I am unhappy that air seems to be able to swoosh in unfiltered around this really naff part - please tell me I have got it all wrong and there is a perfect seal :faint:.
 
Last edited:
I agree but you have to see what a crap seal it is to believe it; I am unwilling to accept that way back even then they thought it was 'OK'.

It looks like a significant proportion of air to the front cylinder was and is never cleaned.

It makes me wonder why I am bothering; Amusingly it was your comment on engine wear with / without filters that scared the bejabbers out of me and made me decide to filter if at all possible. Now it looks like filtering 'sort of happened' for the front cylinder. The filtering for the rear looks OK.
 
Thanks Paddy, those pickies are just the kind of help I needed.

I'll have a play and let you know. Mine has a flappy rubber bit too on the inside but it all seems a bit gappy & lacking in seals between the airbox and this fitting...
P1000711.jpg


P1000710.jpg


P1000709.jpg


P1000708.jpg
 
Yes i think mine is missing the rubber flap which i think is a crude one way valve. My elite single had that as well on the air box. Without that the crankcase pressure would just move up and down its pipe as the piston went up and down.
 
Sorry Paul I don't recollect exactly what was in my air box, but it certainly had the rubber non return flap. The problem I had (and still have to address) is that the carb inlet rubber doesn't quite reach the airbox properly so I just gaffer taped round to seal it. Still don't know why that is but it's on the list for next winter's shakedown. I'm too busy riding it to do any remedial fixes now.


DSC_0150.JPG
 
My oil breather tube looks like it is bedded in some kind of mastic ? to make it air tight . It was certainly fitted before the whole lot was painted.

Derek, does this look like yours length wise ? ,just wondered if yours has been cut down ?

 
Snail's pace...

Reading this must be like watching paint dry!

I fitted the carbs yesterday only to discover my master planning doesn't seem to have been in 3D and certainly bears no relation to reality.

Two problems raised their ugly heads yesterday, first the rear cylinder air filter...
DSCF1625.jpg

I have not yet been able to source a rear inlet tract rubber for a 900GTS (BTW, thanks Paddy - we'll see!) and so used the filters I used to use on the 900SS after a good clean. However the filter sticks out too far for the side panel to fit correctly; Others have found ways of dealing with this and I took my own route...
DSCF1631.jpg

Now fits a treat...
DSCF1637.jpg


DSCF1638.jpg

Made in exactly the same way as the original, Effective, not pretty - and hidden.
Paddy is on his way 'round this morning to drop off a Darmah tract. I had a look at the ones in Paddy's pictures and compared them to mine; According to Paddy they use the same part numbers so I probably won't have to use my kludge. The other problem I had with my old tract is that the rubber or whatever synthetic compound used had hardened making it impossible to fit in any case. I am hoping the one Paddy brings around is still flexible.

At least I have a temporary solution if things don't work out with the factory air filters immediately - I want to start it!

That's the vertical cylinder 'done', now for my genius planning regading coil & horn location for the horizontal cylinder. Ducati have not sprinkled the frame with useful mounting brackets, have a look at this...
DSCF1626.jpg

Where the 'eck is the inlet tract supposed to go? Another numpty moment :o. :idea: I am going to move the horn to leave room for the coil (I hope) in it's original position. It will still involve some hackery on the coil bracket as I am already aware the mounting holes do not match up.

Still, progress!

My new Tomaselli twin cable pull throttle turned up along with my Venhill Pantah throttle cables which all (nearly) fitted together nicely (Hat tip to Stephen Eke for this idea) so I though I'd complete the carburettor installations by connecting up the controls. Would that it was so easy! The cable ends on the Venhills are slightly larger than the receiving holes on the twistgrip, so out with the pillar drill and that is now sorted.
DSCF1629.jpg


Choke cables are a problem - the carbs were so badly corroded, rather than damage the choke mounting plate screw, the cables were cut off. New twin pull choke cables for a GTS seem unobtainable however Back To Classics stock Darmah SS ones which look to be identical - although they are fergin' expensive particularly as Back To Classics seem to charge ~€18 for postage on top as well as higher VAT (is it possible?).

I am approaching the point where there is little else to do than fit the tank & start it. Roll on that moment!
 
Paddy visited today which I really appreciated.

I have to admit the man has prodigious knowledge! It turns out my choke slides have been 'fiddled with', but I have two replacements on the way, a new rear inlet tract and some usable choke cables.

Thanks, Paddy.

I haven't yet had time to reposition the horn & horizontal coil, hopefully that will be sorted over the weekend. The parts for the loom extender/converter have arrived so that is part built; It is necessary as the Monster clutch master cylinder fouls the original switchgear, luckily I have a spare good 996SPS switchgear which is a perfect fit with the loom converter.
 
Re choke plungers, As it happens i dont think yours were drilled out just splayed open to take a thicker throttle cable and nipple rather than a std choke cable.
 
No more excuses! Start the engine...

Did the lawns yesterday and I reckon my wife knows I am close to getting the thing started so I was left alone in the morning - and then again in the afternoon as Tracy went to see her Mum.

There are still quite a few things to sort out, but they can wait; In the short term I will stay with the cable clutch and wait on hydraulic - however now I know what needs to be done, I will go hydraulic with my own interpretation specially for square case LH selector box engines. I think I need:-
  • the Frando 14mm slavecylinder (in hand)
  • the Frando 17mm master cylinder (soon)
  • a weak internal slave piston return spring for the Frando slave cylinder (next week)
  • a modified clutch arm such that the slave cylinder pulls directly in line with the arm.
Unfortunately the standard arm is too short and as luck would have it the extended arm is too long. Hey Ho. Time for some engineering nadgery and I think I'll run the bike over to a couple of very skilled guys with the all the bits and a brief. I have worked out a way of using a short last 10cm of the original finely braided cable to give some flexibility - both the Magura conversion and the Frando slave implement worryingly stiff options for a linkage which has discernible play in most axes.
DSCF1647.jpg


I knew I had a lot to do, but my, was it a battle! I think 'n' years slumber (I think ~20) had given the Dark Side Of the Moon a Herbie like resistance to getting going again.

I am not even sure where to start - so I'll start with my twenty year old son who needed rescuing by my wife at 02:00 this morning - because of diversions she didn't get back until 04:00. Kids, eh?

I couldn't sleep for a number of reasons and tried to calm myself down by working on my loom conversion for 996 switchgear which requires some attention.

Knowing I intended to start the old girl today, my list of things to do included a front to back tightening check. There are a few kludges to get me through - note the missing speedo & rev counter and the paper clip retaining the clevis pin for the rear brake master cylinder.

Kludge #1: rear air filter as K&N isn't yet primed with oil...
DSCF1638.jpg


Kludge #2: rear master cylinder clevis pin retained with paper clip...
DSCF1657.jpg


I have added mounting points for a RH side stand pull and have bought & modified a handle to suit; I added the frame mounting point last year before stove enameling. The RH handle is a dismantled & flipped LH handle and it all fits OK with a bit of adjustment. Both handles are off to the chromer's this week.

Engine wise, it is already filled up with oil & the metal Brancato gauze & magnet primary filter fitted, and the dipstick with magnet. I had to mount the carbs, set up a rear air filter whilst I await the arrival of extra K&N filter oil - I only had enough for the front and 1/4 of the rear.

Sorting out the chokes, cable runs & filters took quite a while. Next was the engine breather pipe - fortunately I had a NOS piece lying around which was a perfect fit. I cleaned the rubber front inlet tract & clips & on went the front air filter with nice new clean K&N's. Not perfect, but better than nothing.
DSCF1642.jpg


DSCF1639.jpg


Time to check ignition. Also a good opportunity to prime the oil pump & big ends with oil before the engine is started, so out came the plugs after a quick blow to clear any crap, and 100 kicks later experience tells me (actually, 80 kicks) the oil has reached the gallery in the clutch cover prior to squirting up the crank to the bigends. The extra twenty kicks get some oil flowing over the ends.

A quick check shows me (FX: Disappointed!!) there is no spark. FX: Worry worry! fortunately 10 seconds with a mutimeter shows me I have a high resistance fuse I have re-used (Dork!) which heads straight for the bin. A new fuse and I have a lovely strong spark, so back in go the plugs.

I hadn't yet sorted out the HT so the cables were cut accordingly and I completed the work swapping the coil around and moving the horn to clear the horizontal cylinder inlet tract from the filter to the carburettor. This involved about three iterations of bracket which was quite frustrating.
DSCF1645.jpg


FX: Phew!

Almost time to start, so I bring the tank down from a 'safe place' banging it on the way down. Oh f:censored:k. Gosh, was I cross with myself but fortunately no harm done.
DSCF1648.jpg


It is quickly apparent that wonderful though the spray job was, he didn't mask the fuel tap mounts. So off with the tank & I head inside to work on a nice soft carpet, banging the tank again! This time it was the brass front door handle and I was really worried. Lucky me again! So after 'really quite a long time' sorting out the threads with a thread file, now I can fit the fuel taps, cut fuel pipe to match and clip the pipe work securely to the carbs. You might notice this GTS has standard SS/MHR/Darmah 16mm fuel tap threads - I had these made up and brazed in when the tank was cut open for blasting & inspection. Makes life a lot easier without that nonsense link pipe designed specifically to make it difficult to remove the tank. Gone forever with this bike.
DSCF1653.jpg


Bloomin' eck, does it ever end!

I had successfully lost the mounting screws for the RH sidepanel, I re-found them whilst turning over the garage looking for something else I had lost and pinched some nylon washers I had spare from buying too many sets of SS seat mounting screws.

The main irritation was discovering that the nice new tank badges I bought from Road&Race in Australia simply don't fit - the pins are a few mm too close together. Fortunately I have the originals and they will be going off with the stand grab handles for chroming; Hence the currently unbranded (on the tank) Ducati. Still, things are looking up...
DSCF1652.jpg


Out with the 5L emergency tank and I have fuel! Unfortunately quite a lot had been used but it is a start and nevertheless, it doesn't leak when I turn it on. It has been a hot close sweaty day so I break for a shower knowing when I come down it is fully ready to start. No chain, mind you but that isn't the point.

I was remembering Derek's comments about starting his GTS after his rebuild and I was hopeful mine would be as easy. It wasn't.

Those 905cc high compression pistons *do* make a difference, as does the 3.5Kg lost from the primary drive/flywheel with the fitting of the Nova Engineering straight cut primary drive gear set. Also the choke which I carefully lubricated keeps turning itself off. Anyway, after about 10 or so kicks, it burst into life, misfiring a bit and I suspect it is because of low fuel, so off I go in search of more fuel and find a full 5L. That does the trick and it really does sound fine although it won't idle at the moment.

By this time Tracy is home and I have asked her to witness the inaugural post testing start. The weight of responsibility is daunting :). She does like the colour...
DSCF1658.jpg


Time to fit my new DID 'O' ring chain with my new DID 'O' ring chain tool. It's a first for me as I am usually a cop out going for split link chains. The tool is well made and the instructions are good so on it goes.

The primary drive ratio for the Nova primary drive gear s is different so I have gone for a 40 tooth rear, I was unhappy using a 16 tooth front with the big Daddy DID 'O' ring chain chain so I have gone for a 15 tooth gear and I am going to see how it pans out.

Time to remove my hydraulic clutch conversion parts as I have a few things to do before I can fit & forget it, so off comes the LH switchgear so I can mount a conventional clutch cable; All fitted and clutch works fine.

For the absence of any doubt, the gear change feels completely and utterly different from a later LH quadrant engine. In my humble opinion it is sweeter and works better.

I live out in the sticks (for England) so there are plenty of private farm access roads so I put on my helmet and push it to a farm for a quick test.

Time to ask Tracy out to see it start, which isn't particularly easy as I don't yet have the knack. It is *completely* different to the SS.

Conclusion? Absolutely fan-bloody-tastic. Sweet engine, sweet comfy handling and great noise. That straight cut primary drive makes it sound like you are sitting on a full race engine, it isn't just the exhaust that sounds great, the mechanical noises are epic; Nothing like the SS (and much better).

I think the rear mudguard treatment I have given the bike gives it a slightly scambler'ish feel, although I am definitely not looking for any off road excursions ;).

I don't show the RH side of the bike much - mainly because it is in the shade near the border with my neighbour, but here it is...
DSCF1660.jpg


DSCF1665.jpg


DSCF1659.jpg


DSCF1661.jpg


DSCF1663.jpg


It wasn't a smart move starting this project, but I think even Tracy likes it. Like might be too strong a word, but it is a great bike and I am looking forward to taking her out for lunch on it, when I'll be on the Lime & fizzy water. All good.

P.S. I hope you notice the contemporary lawn mower in the background, I only wish the GTS was as reliable ;)
 
Last edited:
I think what's most important here is to remember what the starting point was. How many people would have had the bloody minded drive and determination to bring that sh*t heap back to life?
Paul - I take my hat off to you. You're a miracle worker. I remember bringing my GTS home and convincing my wife that I wasn't an idiot by showing her your Dark Side Of The Moon. Somebody far more ambitious (stupid) than me!
It's simply a masterpiece - and a unique tribute to your hard work. Well done and I look forward to seeing it in the flesh.
Derek
 
Oh, and I had the same issue with the Road and Race tank badges. My painter cut off the lugs and fastened them on with some kind of sticky pads.
Thanks for this! The badges aren't as good quality as the originals, either.

I think I will follow your lead and in parallel get the originals re-chromed, at least it will look right whilst I wait.
 
I agree with Derek its an excellent job, most impressive to me is the the way you stuck to your plan and the finished job looks just like you planned it. If it had been mine it would have had several complete personality transplants along the way and would look nothing like the start out picture/aim.
Why do you think i have not posted much on my project. :-) It started life as a Darmah framed Elec start and is already a 900S2 framed kick start only. I just started building engine number 2 :)
The fact that yours now looks like you said it would is a minor miracle to me .
 
I agree with Derek its an excellent job, most impressive to me is the the way you stuck to your plan and the finished job looks just like you planned it. If it had been mine it would have had several complete personality transplants along the way and would look nothing like the start out picture/aim.
Why do you think i have not posted much on my project. :-) It started life as a Darmah framed Elec start and is already a 900S2 framed kick start only. I just started building engine number 2 :)
The fact that yours now looks like you said it would is a minor miracle to me .

Ah, you mean like this?
softwareengineeringexplained1r550x413.jpg
 
Badges make a difference - thanks Derek for the tip. I thought it was just me but I guess these (expensive) badges are inferior re-manufactured items. FX: Sigh...

Never mind, here they are on the bike - I retained the front pin on both sides to help locate the badges...
DSCF1668.jpg
 
Last edited:
Back
Top Bottom