Saw an ad for a 1990 750 Sport near me for... not much money. So I sent a flurry of messages throughout the day and made him stay up past bedtime to meet me.
Owner had purchased the bike in 2000 - already outfitted with 36mm pumper Dellorto setup, some familiar wiring mods and Ferracci mufflers (!) - and other than some dust and road grime, it was very clean. He said that it had a bent valve - but somehow ran - and that it just bogged under acceleration. I'm no rocket scientist, but I didn't think all of those things could be true at the same time. We tinkered on it past 10pm in his garage, seems the 2nd cylinder cam was off a tooth - but he admitted he had 'played with the timing belts' before he listed it. Thankfully we didn't use the starter to test immediately! I got it timed correctly, and was eventually able to turn it all the way through with the rear wheel. I borrowed a battery to try the starter and both cylinders had compression. Anything else I was sure I could figure out, so gave him cash and brought it home.
I host a bike/shop night at my coffee bar in Seattle - we work on bikes and help anyone that needs guidance navigating simple issues. Between serving beers I'll hop into the fray to futz with whichever project is queued up. I INTENDED to go through the top end before attempting a startup, to make sure everything is where it should be, but after a chat with a veteran moto tech, his advice was if there's no interference and compression, just send it. So, I dribbled some fuel down the hose of this beautiful thing and hooked up a battery. A couple cranks and it roared up and calmly settled to an idle. Sounds amazing and I was the coolest guy in the Pacific Northwest for about 5 minutes.
Shortly after this amazing moment, someone bumped a galvanized pipe that was leaning on the wall and it fell right square on the rear seat cowl, cracking it on a very unfortunate corner. I had to walk away and find a quiet place for a few minutes, but otherwise it's been an exciting, if bittersweet 18 hours of ownership.
When everyone left I put in a late night with the bike on the lift. I tested compression - ~115psi in each, though I don't have full confidence in this gauge. Scope just showed heavy carbon on the piston, and maybe a little nick from a valve kiss, but otherwise a very clean combustion chamber with a nice hone on the walls. No real evidence of a catastrophe. Accelerators on the Dellortos spray cleanly and slide action is smooth. A manual came with the bike and there's a sheet stuffed in the back with a running log of maintenance covering the last 25k of its 33k mile life - also detailing accounts of a camping trip he took with his dad where it fell off the sidestand in some dirt, and a lowside incident from some sneaky gravel - which explains the spare fairing that came with it.
I have no idea why the PO thought it had a bent valve, he couldn't give me a real answer about how he came to that diagnosis - overheated, I played with belts, it ran fine, etc. Nice guy, but I suspect his bogging was something else that I may eventually discover and he was just ready to move on. I will check valves and all the systems before doing any more vroom vroom, and there are some maintenance parts on the way - belts, sprockets, chain, battery, oil filter, etc. I will eventually drop the engine and inspect the top end, as it's a nagging thought, but I'm otherwise very happy to report another running, weird Italian in the stable.
Some notes and observations:
- While it has the turning radius of a Cadillac, this thing is incredibly light and easy to move around.
- I didn't realize the connection between the 750 Sport and the Paso. I have a VERY yellow Paso I picked up years ago as it is exactly the kind of ugly, weird, beautiful stepchild moto I'm drawn to. Whereas the Paso is unfortunately in storage and rarely ridden, I'm itching to get the Sport out and I already have a line on some liveried bodywork to give it a spare outfit. Anyone taken theirs to a track day??
- I have the rear inner fender, but PO ran it without. Other than the obvious potential issues, anyone had problems running without it?
- I know I'll find out on first ride, but any feedback on the shift lever placement? The Paso is notoriously awkward shifting, can I expect an improved experience with this younger sibling?
- Yes that's an Elefant in the background, I said I like the weird ones.
/very excited from Seattle.
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