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Discussion Starter · #1 ·
I've had my '03 620 since 2005 which I got with only 461 miles on it.

I added Termi's at about 4500.

My ECU went bad at about 5500 miles but I had JUST purchased a 2 yr after-mrkt warranty so that saved me about $2k.

About 7000 miles I lost a cylinder (i.e. NO power, but got it to the dealer about 4 miles away). Turned out to be the valve guides. Took2 weeks to have the guides machined and another week for a new assembley from Ducati. After a month in the shop at LEAST I had that warranty.

I kept it under 5k RPM for 300-400 miles (which SUCKED!) but the rings should've broken in well. The service manager said to "let it rip" after I took it by to tell him about running hotter and the engine dying at stop when clutch pulled and using only brakes to stop.

Still since the "rebuild" of the front cylinder the engine would die on downhill decel as soon as I pulled the clutch more often than it did before. It also ran hotter than normal (260F) in SoCal 70F temps. I had Ducati dealer richen the mixture, but they weren't sure that solved the problem. Service Mngr mentioned that fuel pump may going bad. After mixture enrichment popping was more frequent. It pops repeatedly on decel as usual, but even when cold, warm hot, very minor decel, even momentary accel, and heavy decel is pop-pop-pop-pop. Engine also started dying when warm on downhills or decel when clutch pulled. Dealer said this can be normal as long as it's not "backfiring" with one LOUD bang.

I had to put in the silencers because I was almost embarrased by the sick sounding engine roaring or COUGHING down the street. I can still hear it through the Tremi silencers quite loudly.


A friend thinks they may have enriched the mixture too much. Could this be the case. What about the fuel pump. I have about 6 months left on the warranty so I definitely should get it fixed before then. Althought I'm thinking of selling it while the warranty is still good.
 

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My guess is that your friend is correct; considering you've only changed the exhaust, it should run ok with the std. settings for fuel mixture. My other Ducati - a '78 500 SportDesmo - has had the same problem, and with a better fuel mixture the popping is gone.

Good luck!

OttoDesmo
 

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Discussion Starter · #3 ·
I'm going to put in my Open Box Air Intake that came with my Termi's and see if that leans out the mixture a bit.
 

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Discussion Starter · #4 ·
Gunked up Pluggs. Mixture to rich or bigger prob?

I put on the Open Box filter lid and still had pretty obnoxious popping.

I pulled the plugs and the front horizontal cylinder plug was SO gooked up it was no wonder I wasn't getting good burn. I also noticed what looked like oil around the threads. I lightly scraped some of the black junk before reinserting. Looking at my other plug on the vert cyl it was much cleaner. Just the typical dirt brown on the spark "arc" (wish I had a pic to show), but there was black around the top of the threads so still a bit rich.

I'm thinking that if it was just a mixture problem both plugs would be similarly black. Perhaps this has to do with the work I had done a few months ago redrilling the valve guides and new piston assembly. It's the same cylinder that's getting the gooped up plug.

I will acknowledge that it popped MUCH less (almost back to typical Termi decel gurgle) after brushing off the heads. It still did bog a few times on twisting the throttle.

We'll see if it holds up on the 5 miler to work this morning. Anyone have any ideas on what's going on? I'm not confident in my local shops assessment. Unless I'm spending tons of cash, they don't take the time to properly assess.
 
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