'77 500 head gasket

If you need technical information or help with your parallel twin Ducati GTL 350/500 or Sport Desmo 350/500 engine - post your FAQs, comments & questions here.
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Spagjet
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'77 500 head gasket

Post by Spagjet » Mon Jan 13, 2014 5:53 pm

My father has got a '77 Sport Desmo that is weeping oil from the head gasket. Anyone know where to get a new one? He has tried tightening the studs, no go...

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Craig in France
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Re: '77 500 head gasket

Post by Craig in France » Tue Jan 14, 2014 8:20 am

Spagjet wrote:My father has got a '77 Sport Desmo that is weeping oil from the head gasket. Anyone know where to get a new one?
I'm guessing you've already tried Ian Gowanloch -? If he hasn't been able to help, try Giovanni Gentile at Classic Italian Bikes in the Netherlands.

Look at eBay item #390408812529, and/or go http://www.classicitalianbikes.com/, e-mail gio655@hotmail.com.

HTH

Craig

Spagjet
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Re: '77 500 head gasket

Post by Spagjet » Tue Jan 14, 2014 2:14 pm

[quote="Craig in France"][/quote]
I'm guessing you've already tried Ian Gowanloch -? If he hasn't been able to help, try Giovanni Gentile at Classic Italian Bikes in the Netherlands.

Look at eBay item #390408812529, and/or go http://www.classicitalianbikes.com/, e-mail gio655@hotmail.com.

thanks very much Craig, I'll follow it up

Spagjet
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Re: '77 500 head gasket

Post by Spagjet » Wed Jan 15, 2014 8:17 pm

( :10-HUT: Some previous posts in this thread have been edited by The Admin as well as inappropriate comments and responses to those inappropriate comments - PM sent directly to the main culprit - no more of that please - lets keep everything on track :vroom: )

I checked out the item you suggested on ebay, it's for a 350. I saw that one when I checked eaby before which showed me that you probably couldn't make one as there is a copper fire ring round each pot.

A Ducati with a head gasket just doesn't seem right to me, ha ha ha.

I told my old man about this forum a couple of days ago and he told me he has joined up too. He just had his eyes operated on today so he's probably not going to be worried about leaky head gaskets for a few days. He's 75 but has got the SD500 and also a Guzzi Nevada and an old Suzuki rockhopper thing so I have to take my hat off to him. I hope I'm still playing with motorbikes when I'm 75 (I think I will be)

Hmm, is a 500 just a stroked 350 with the same head gasket? I just thought of that.

I really don't know so many things, that's what makes life interesting.

ducadini
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Re: '77 500 head gasket

Post by ducadini » Thu Jan 16, 2014 3:07 am

Spagjet wrote: I checked out the item you suggested on ebay, it's for a 350. I saw that one when I checked eaby before which showed me that you probably couldn't make one as there is a copper fire ring round each pot.

A Ducati with a head gasket just doesn't seem right to me, ha ha ha.

Hmm, is a 500 just a stroked 350 with the same head gasket? I just thought of that.

I really don't know so many things, that's what makes life interesting.
No, bore/stroke differ on 500 and 350.
The first type of 350/500 WAS without gasket but leaked compression due to distortion of the head. Leaked some oil also.
Tended to crack on the part behind the head where the chain-tensioner sits.

Here's a complete set, maybe they have them separate ?
http://www.stein-dinse.biz/Ducati/Guarn ... :3077.html

Only the gasket :
http://www.ebay.it/itm/GUARNIZIONE-DI-T ... 54032a341c

The clearance between head and cilinder for the o-rings at the front is critical.
Be sure to measure carefully before tightening and look for o-rings that are tight around the dowel but a little thicker.
You have the special tool for the outer nuts ?
Don't forget to "wind up" the chaintensioner BEFORE fitting the head (see manual).
Keep an eye on the 8mm bolt at the rear of the head, try to tighten it in about the same way as the head itself, or You could crack the rear part of the head.

Working on Ducati's for some years now, never cease to amaze/irritate/puzzle/bewilder/confront me.
I guess it's something more of a "Taglioni era" against his predecessors/ apprentices ?

cu
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

Spagjet
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Re: '77 500 head gasket

Post by Spagjet » Mon Jan 20, 2014 9:11 pm

Hi Ducadini,
thanks for that info, it all sounds like very worthwhile points, I will tell the old man to check out this thread, he can't see at the moment but will be able to soon. I understand what you mean about the bewilderment etc, I bought a '75 GTL500 (and a '72 Maico MC400, offered a job lot price to the bloke for both, barn finds) and was getting quite attached to the little Ducati and making plans for restoration, etc (it was very complete and in amazing condition really) but couldn't get past the camchain thing (and endless negative feedback on early GTL's I found once looked into) so sold it on for $1200. Still haven't worked out if I regret it or not yet. They are fascinating little animals if for no other fact that they are neither bevels or belts, and of course the parallel thing. If I had more room I probably wouldn't have been able to bring myself to sell it on but I've got so many motorcycles and motorcycle projects now it would have just been a "room taker upper" for years.

I think the old man's "77 Sport Desmo is an altogether different bag of cats though. I'll tell him to check the thread out, thanks again

ducadini
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Re: '77 500 head gasket

Post by ducadini » Mon Jan 20, 2014 11:27 pm

I've had a Sport Desmo for almost two years (before upgrading to Darmah and SS) and when it ran, it ran FANTASTIC.
Magnificent roadholding, low but a (big) tad heavy.
You could fit race-cams (VERY hard to find) to boost the power, and shorten lifespan to months :-)
When looking for spares for the SD, always check that the engine parts must be of the later type.
Ducati changed heads, cilinders and crank after the first type of GTL, but all parts of the later are interchangeable.
If all fails, put a single in the frame, it's not a straight swap, but not too difficult.

ciao
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

Spagjet
Mach 3
Posts: 79
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Re: '77 500 head gasket

Post by Spagjet » Tue Jan 21, 2014 12:33 am

I was very seriously considering doing just that to the '75 GTL I had, keep the original engine as a house ornament and put a 500-600cc Jap trail bike single in it's place. It would be just beautiful I reckon, all say how good the GTL handled, could only be better with a lighter engine and I've always wanted a big single road bike. I figured if you carefully removed all brand names off the cases you could just register it as a Ducati single if the transplant job was neat enough and it had speedo, blinkers, etc.
Stumbling point was rarity and expense of rebuildable big Jap singles nowadays because of go-carts, racing mowers, cafe racer projects, etc. The ones I found were in VERY bad condition with BIG prices on them. Great idea but everyone else thinks so too. Then I looked at all the other bikes in bits here and gave up on the whole idea.

How many bike projects are enough bike projects?

I even thought about putting a 400cc 2-stroke Maico motor in it.

A bit hard to pass off as a Ducati single at the rego joint

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