750 Sport restoration project

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
HIGHWAY89
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model: 900 SS
year: 1989
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Re: 750 Sport restoration project

Post by HIGHWAY89 »

They are pretty rough guestimate, another look tells me pistons more like 25 mm and maybe 26.5 mm on bore
Andrew2
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model: 750 Sport
year: 1988
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Re: 750 Sport restoration project

Post by Andrew2 »

I'll measure mine tomorrow and get back to you. The seal is 26mm outside diameter so your bore would probably be less than that I would say.
Andrew2
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model: 750 Sport
year: 1988
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Re: 750 Sport restoration project

Post by Andrew2 »

Here's the measurements but for some reason the piston diameter kept coming out higher than the bore diameter haha. I couldn't get the verniers far enough into the bore. The piston is a nice snug fit with a small amount of movement.
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HIGHWAY89
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model: 900 SS
year: 1989
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Re: 750 Sport restoration project

Post by HIGHWAY89 »

Andrew it looks as though we both won't have any worries there, go fo it mate , especially with the v seal you'll be sweet. Looking forward to seeing your progress going forward.
Andrew2
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Re: 750 Sport restoration project

Post by Andrew2 »

Cheers. I'll have a crack at it in the next couple of days. Once that's done it's ready to ride so fingers crossed it'll work.
Andrew2
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model: 750 Sport
year: 1988
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Re: 750 Sport restoration project

Post by Andrew2 »

I finally got around to putting the new clutch seal in today. All went well except I couldn't get any pressure on the clutch lever byt doing a normal bleed so reverted to this.

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That still didn't seem to work so I thought I'll put it back on the bike lift and pull the clutch cover off again. I put the master cylinder cover back on and strapped the lever to the bar while I had a coffee and when I returned I had pressure in the lever. Enough to disengage the clutch and roll the bike in gear. There still feels like there's a small amount of air in the system but I'll work on that later.
I then took the valve covers off and put some oil around the desmo gear and a little bit in the spark plug holes. I've put the fairing back on and will run a spanner over everything tomorrow.

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For some reason I neglected to take any photos :banghead: .
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higgy
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Re: 750 Sport restoration project

Post by higgy »

most folks find to get the last little bit of air out of the clutch requires removing the reservoir off the bike and pointing the lever at the sky

http://www.forums.ducatipaso.org/viewto ... f=1&t=5467
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
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HIGHWAY89
paso grand pooh-bah
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Joined: Sat Jul 16, 2016 6:35 am
model: 900 SS
year: 1989
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Re: 750 Sport restoration project

Post by HIGHWAY89 »

Sorry to jump in here , Andrew thats awesome you're really getting close now mate. Higgy thx for that info you provided, I need to really have a good look at it, but looking at this thread I think I will try removing the master before anything else,and give it some sky action.
HIGHWAY89
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model: 900 SS
year: 1989
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Re: 750 Sport restoration project

Post by HIGHWAY89 »

Mate while I was writing on your thread I strapped my clutch lever to the bar and just released it , now I have some pressure, it feels like a half bled brake or a brake needing some adjustment. So I'm still struggling as I would expect to be able to pull the lever to the bar.
Andrew2
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Joined: Thu Oct 27, 2011 7:47 am
model: 750 Sport
year: 1988
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Re: 750 Sport restoration project

Post by Andrew2 »

I wasn't getting anywhere just doing the normal bleeding method so I used the vacuum pump. It seemed to suck a lot of air out. To much to be honest but some of it was probably leaking where the tube connected to the bleed nipple. It still didn't work real well so I strapped the lever to the bar for maybe 15 minutes and when I went back out it was a lot better. It still doesn't have a lot for the first maybe 10-20mm of lever travel which is why I think there is still a bit of air in there. I'll crack the bolt on the master cylinder and see if there's a bit trapped in there. I did try and get the master off to hold it upright but can't see an easy way to get it off without dropping the fork leg?.

P'S. I also tried reverse bleeding it before the vacuum pump. I lost a lot of fluid on the ground but maybe that helped.
Andrew2
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model: 750 Sport
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Re: 750 Sport restoration project

Post by Andrew2 »

I just removed the 20 mm slop at the start of the lever pull by screwing in the clutch lever screw. I'll do a proper bleed with fresh fluid after I take it for a ride to test it out.

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Andrew2
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model: 750 Sport
year: 1988
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Re: 750 Sport restoration project

Post by Andrew2 »

I got a step closer to going for a ride on her today. Fitted up the air cleaner. I'll be getting some reusable cable ties tomorrow.
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Andrew2
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model: 750 Sport
year: 1988
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Re: 750 Sport restoration project

Post by Andrew2 »

Next up was nipping up the fairing and tail section then temporarily fitting up the tank and seat.

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And then off the lift with you....
Andrew2
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model: 750 Sport
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Re: 750 Sport restoration project

Post by Andrew2 »

....only to find I had barely any steering lock on the right hand side,mmmmm......

Further inspection found the steering damper wasn't fully extending so back inside to have a look at the dismantling photos and problem found. I put the clamp on the fork on the wrong side.

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Spun it around and all good again. :thumbup:

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Andrew2
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Posts: 562
Joined: Thu Oct 27, 2011 7:47 am
model: 750 Sport
year: 1988
Location: Wollongong,Australia

Re: 750 Sport restoration project

Post by Andrew2 »

Now the exciting part...or not. Time to fire her up. I pulled the plugs out and rolled her in gear a few times then popped the plugs back in with a little "start ya Bastard", connected up the jumper leads to the car and turned on the ignition. The dash lights came on so I hit the starter button. Slow cranking then nothing. Ok, I'll start the car for more omph only to find the car battery flat but it finally started. Back to the bike and she's turning over like there's no tomorrow but won't start. That's when the biggest storm we've had in a while hit so back into the garage. I'm thinking why won't it fire which is when I realised I didn't connect up the fuel pump wires :banghead:

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