Displacement bump

discussions specific to the 750 Paso

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jklnhyde
Posts: 36
Joined: Sat Oct 31, 2009 1:14 pm
model: 750 Paso
year: 1988
Location: Jacksonville, NC USA

Displacement bump

Post by jklnhyde »

Has anyone bored or stroked their 750? What would be the easiest and least expensive route to more cc's and HP? Are there any specific guidelines to follow when overboring a Ducati cylinder or case?
Rick
Rick
2004 BMW K1200RS
2004 Royal Enfield Bullet 500
1988 Ducati Paso 750
1981 Honda CBX 1050

'It's not the kill, it's the thrill of the chase"
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: Displacement bump

Post by ducinthebay »

In general, the 750 engine is not a great candidate for hop-up ugrades. You can add some Hi compression pistons, cams, and improve the carbs and exhaust, and lighten up the internals with smaller flywheels and drilling holes in gears. With all that, it will run with a stock 900. But after that, its just very difficult to get much out of it. For a more complete and technical write up, see: http://www.bikeboy.org/performance.html#2v

The biggest limitation to the 750 motor is the heads and the flow. I looked at putting on some 800 heads, which have big valves like the 900, and the same bolt pattern as the 750, but the dome is deeper and new pistons would have to be sourced, that may not be made. I'll sell you the heads if you are interested.

The easiest and fastest way is to simply put a 900 motor into your 750. Larger displacement, larger valves, better selection of cams, and you can get a true 100hp if you spend enough money in upgrades. If you keep an open eye, you can pick up a good used 900 motor for less than $500, which is pretty cheap hop-up for 15hp. Heck, hi-comp pistons alone are $500.

The 750 Sport is really easy to upgrade, as a 900 motor will drop right into the frame, and you simply use a later model SS swingarm, and your done.
The Paso swingarm arrangement is a different story. I have no idea what it would take to adapt a 900 motor to a Paso.

Cheers,
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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ducapaso
paso grand pooh-bah
Posts: 1097
Joined: Sun Aug 01, 2004 12:00 am
model: 750 Paso
year: 1988
Location: siena, italy
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Re: Displacement bump

Post by ducapaso »

I found a big bore kit for paso some time ago but i'm no more able to find it.
It was a780 tuning kit from an italian factory
have a nice ride, Nicola

Black "DUKE" 751582
ex...Red "smooth" 753349 :-(
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21783mike
Posts: 102
Joined: Thu Aug 28, 2008 9:48 am
model: 750 Paso
year: 1987
Location: Smithsburg, MD

Re: Displacement bump

Post by 21783mike »

Try Ed Milch He's been known to squeeze a bit more out - http://ducpower.com/
Mike B.
08 HYM 1100S
06 800SS
89 KLR650
87 750 Paso LTD
64 125 Bronco
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higgy
paso grand pooh-bah
Posts: 3378
Joined: Tue Jul 29, 2008 9:50 pm
model: 907 I.E.
year: 1992
Location: Hilltown,Pennsylvania
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Re: Displacement bump

Post by higgy »

Now available: 82mm/88mm/90mm Wiseco High Compression (13:1) Racing Pistons for 2 valve Ducati 650's and 750's . These forged racing pistons will increase both your torque and horsepower by ~10% compared to stock pistons. 82mm/88mm sets are drop-in and require no rebalancing of your crankshaft. 90mm pistons require additional work. These pistons require 110 octane racing fuel and are for closed course competition only.

Price is $350 per set of two. Rings, wrist pins and clips are included.
To order, please contact:
ed@bimotacagiva.com
Ed Milich
Bimotacagiva.com
PO Box 5
Torrance CA 90507
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
88 750
90 906
92 907ie
jklnhyde
Posts: 36
Joined: Sat Oct 31, 2009 1:14 pm
model: 750 Paso
year: 1988
Location: Jacksonville, NC USA

Re: Displacement bump

Post by jklnhyde »

Okay, all good advise, but what about the 906/907 models? They were bored/stroked versions of the Paso 750, a sure drop-in for a carbureted 750/906 swap. Is this not a good swap? Would I get more satisfaction out of a bore job?
I'm not looking for all-out HP, but I do have a garage full of 100+HP motorcycles and would like the Paso to have a bit more go.
I do like the simplicity of a 88mm piston upgrade, but I'm not so sure of the availability of 110 octane fuel when I need it...
Rick
Rick
2004 BMW K1200RS
2004 Royal Enfield Bullet 500
1988 Ducati Paso 750
1981 Honda CBX 1050

'It's not the kill, it's the thrill of the chase"
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