Motorcycle Classics

The Paso Lives

The Paso’s Weber-induced drivability issues soured the bike’s mass appeal, yet the Paso’s tuning problems were quickly solved by enthusiast owners.

When I bought my 1988 Ducati Paso 15 months ago, I acquired a low-mileage, cosmetically cohesive but mechanically uncertain survivor that hadn’t turned a wheel since 2003. Fifteen months later, it’s now a fine running machine, and getting it there has been both fun and frustrating.

Part of the fun has been taking a deeper dive into the evolution of the Paso, perhaps one of the most maligned models in Ducati’s illustrious history. I’ve shared plenty of thoughts on that subject previously, but the more I learn about the bike — especially now that mine’s a running, riding proposition — the less I understand why the Paso earned such a huge black eye.

There’s no question but that the Paso’s Weber-induced drivability issues soured the bike’s mass appeal, especially given that it came out in an era when the Japanese were proving that it was more than possible to make sexy, sophisticated bikes that were easy to ride and own. Gixxer, anyone? Yet the Paso’s tuning problems were quickly solved by enthusiast owners who found that fitting conventional Dell’Orto or Mikuni carburetors eradicated the Paso’s running problems. Specialty companies like Malossi stepped in, offering conversion kits complete with carburetors, manifolds, and throttle and choke cables, proving that despite the negative hype, there was nothing keeping you from having a perfectly performing Paso.

Although presented as technically advanced when new, mechanically there’s nothing that radical about the Paso. While its desmodromic valve scheme grabs attention for its seeming complexity, it’s not that hard to wrap your head around once you work with it a bit. For years, I’d heard the talk and given credence to the notion that Ducati’s belt-driven L-twins were devilishly difficult to work on, what with timing belts needing replacement every 10,000 miles or so and challenging to calculate and hard to adjust shimmed valves. I’ll grant that adjustment is involved, but that’s mostly due to the multitude of possible shims you need to have on hand. The actual process isn’t that hard, especially on later models like my 1988, which don’t require rocker arm shaft removal for adjustment, a feature advertised by gold-colored valve covers.

One of the first things I did was replace the timing belts. Even if they were new when the bike was parked, that meant they were at least 18 years old, and I wasn’t going to start the engine and chance breakage, something you definitely do not want to experience, unless of course you enjoy removing cylinder heads and replacing bent valves. And that short 10k replacement interval? Why? Don’t timing belts on cars last over 100,000 miles? Yes, they do, but if you compare the belt routing on the Paso to your average Toyota you’ll notice the very tight turn the belts take over the timing gears, something Ducati engineers took seriously, appreciating the stress this applies to the belts. While I’d wager 10k replacement is playing things very safe, the fact is belts are cheap ($65-$95 a set), and they’re easy to replace. Frankly, it takes more time to remove all the bike’s plastic bodywork than it does to replace the belts, which almost fall off once you’ve removed the tensioners. And they’re easy to set, the process aided by the absence of valve spring tension acting on the camshaft, a nice byproduct of the desmodromic scheme.

Adjustment is a go-no-go affair using a 5mm and 6mm Allen wrench, the former dimension on the front cylinder, the latter on the rear to accommodate that cylinder’s hotter running temperatures, shrouded from the air stream as it is. Adjust the belt tension until the Allen wrench just slides through and you’re set. Adjustment on modern Ducs is done by recording the belt’s harmonics, but years of real world experience suggests the old-school method works just fine.

The Paso’s suspension matched its sporting ambitions, with Marzocchi M1R forks up front and an -hlins mono shock out back. The M1R forks feature adjustable anti-dive, the right side taking on rebound duties and the left side compression, while the multi-link, progressive rate, air-charged -hlins rear features adjustable compression and rebound. I haven’t had to touch the rear shock, but I did disassemble the front forks, a fairly straight-forward process, save for finding the correct fork seals — I ended up buying three sets before finding ones that worked. Set #1, quality Italian Ariete seals, simply would not drive straight into the fork stanchion, binding as if the outside diameter was too large. Assuming installer error I ordered another set. Same problem. Set #3 were Japanese seals from BikeMaster; they installed without issue. Go figure.

I’ll share the rest of my experience getting the Paso up to speed next issue. Until then, ride safe.

— Richard Backus/Founding Editor

  • Published on Dec 15, 2021
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