EXPERT ADVISE NEEDED! DESPERATE!

[Guest Michael Derby]

OK Guys, you all have been great with info and suggestions every time I call on the board for it. Somebody help me decide what to do? I am very frustrated.

 

Background: '04 Nero Corsa 4k miles - Added Titanium Exhaust / Powercommander. Took bike to a local Ducati Hopshop in Atlanta called "DUCSHOP". They put on the exhaust and PCIII, put on Dyno and custom made map. Bike ran great. Then I added a Stucchi X-Over, and K&N Airfilter with airfilter lid removal. DUCSHOP again did work and dyno tuned.

 

Within first 200 miles or so I started to develop a cough / sputter / hesitation around 3-4k rpm, and then I started getting it in 1st when taking off. I bring bike back to Ducshop, they Dyno again, it seems fine, then 50 miles and it is doing it again. I bring back 3rd time and the owner, who is very good, used to be a mechanic for a US Ducati Racing Team, and who used to race as well, spends a good hour or two on the dyno tweaking it. After that he pulls the plugs, mentions that the plugs look to be in bad shape, but doesn't have the right ones to replace them.

 

I get the plugs from dealer, bike runs awesome! I am stoked! All this takes place over past 2 months or so. It has run very well for past several hundred miles.

 

- BUT........ IT"S BAAAAACK!

 

This is the wierd thing, it happens after I run it very aggresively. Sunday I go on a very hard ride where I am hard accelerating, and running through the rev range, sometimes speeds in triple didgets, etc. Not smacking the rev limiter or anything but riding the North GA Twisties very hard. It is running amazing and feels awesome I am riding it to the edge of my abilities.

 

At end of ride it is coughing / sputtering / hesitating when I am trying to accelerate. It is so bad I don't think I am going to make it home. I nurse it for 10 miles or so and it get's better and better.

 

I take it out a 2nd time Sunday evening, run it hard and it happens again, this time it keeps hesitating and sputtering through rev range every so often. Especially through 3 - 4 k rpm, and also in 1st on start up.

 

I take it out tonight, and without running hard it is having spurts of coughing / hesitating / sputtering again especially in 3 - 4k range and when first taking off.

 

Any thoughts?

 

Would you suggest bringing back to Ducati shop? But they are not Guzzi experts. But they did the work and are Dyno experts. Or bring to dealer? But I don't think they have Dyno, but are Guzzi experts.

 

What could it be? When the fuel map is set it doesn't change after a hard ride? Should I abandon the custom made map and get one from GUZZITECH or something?

 

Is it something simple that could be causing this? I just want my bike purring again - Like everyone else on this site I am madly in love with this machine and this is pissing me off.

 

Thanks in advance!

[Guest ratchethack]

Michael, something's outta whack alright, but I wouldn't go changing maps at this point. I'll bet it's something simple. Coupla questions. When your guy pulled the plugs and said they were in bad shape, how did they read? This could be important. Also - has it been hard to start at all (warm or cold), or does the havoc only start when it's good & hot?

 

EDIT: After a quick re-read of your post, it sounds suspiciously like the infamous "tank insulation sucked down on the open airbox syndrome", in which case you can lift the rear of the tank and find the previously mentioned insulation choking off your open airbox. Give that a look.

[Guest Michael Derby]

Michael, something's outta whack alright, but I wouldn't go changing maps at this point.  I'll bet it's something simple.  Coupla questions.  When your guy pulled the plugs and said they were in bad shape, how did they read?  This could be important.  Also - has it been hard to start at all (warm or cold), or does the havoc only start when it's good & hot?

57155[/snapback]

 

 

Thanks for responding. The plugs didn't look good. I am no expert (at all) but they were white-ish and crusty on top and pretty dark and black on inside, one side was black and glossy and other side was brown and sort of fuzzy looking. I think I have them and can take a picture and post. As for problems, yes they only happen when pulling through the rev range. No problems what so ever on starting or idling at all, it idles perfectly at 1k and smooth.

[Guest ratchethack]

Michael, check my edit in prev. post above.

 

There's lots of different ways for plugs to not look good. Many tell explicitly incriminating tales. If you can post pic's - they might be worth a thousand words apiece...

[Cliff]

Its not uncommon for plugs to look uneven on the Guzzies.

 

You should be able to save your map before try another map. That would be a simple check. You can also tweak your custom map.

[Guest aironepony]

I thought that this might perhaps be useful. It's basic but informative......

 

NGK Plugs

[Guest Nogbad]

Just a suggestion, but with all the tuning work and your problems after hard riding I think the plugs you are using are perhaps too hot a rating for the use. This would cause wear and burning of the electrodes. The glossy effect you describe is fused combustion deposits and is indicative of excessive electrode temperatures.

 

I would try a grade or two cooler plug, NGK should be able to advise you. The disadvantaqe of cooler plugs is that they may soot up if you drive the bike in town or make short winter trips.

[jrt]

Try the simple thing first and set the PCIII map to "zero". Then run it after you unplug the PCIII. Probably won't help, but it's simple and eliminates the PCIII and the map.

J

[Guest ratchethack]

Gents! Interesting responses. Michael's "cough / sputter / hesitation" symptoms are clearly followed by clean running for substantial periods without any intervention after the problem surfaces.

 

Here's why I rule out both plugs and the map:

 

1. Plugs that are either fouled or burned badly enough to either cause or result in these symptoms one time will stay fouled or burned, not allowing ANY clean running whatsoever, let alone repeatedly allow clean running up to 50 miles afterward as Michael describes. BTW - plugs that get as bad as he describes point to a cause other than the plugs being incorrect. I have nearly the same set of mods on my Guzzi. No heat range plug "in the ballpark" could be the cause of these symptoms, though the plugs as described could certainly be the result of another problem.

 

2. PCIII Maps don't degrade in quality, and they aren't intermittent. Code is what it is until it gets re-coded. I wouldn't expect dyno maps of any description to result in these kind of symptoms once the bike gets a solid dyno pull and that map is stored.

 

Looks like Michael hasn't been back to this thread. Any bets it's the tank insulation choking off the open airbox as I suggested last night in my EDIT above? If not, my next choice would be "tank suck". It's not likely vapor lock, as his is an '04, and I don't think any '04's had it. Without more info, I ain't got a thing after that...

[al_roethlisberger]

Another suggestion....

 

As is obvious from the posts, it could be a number of things... but other than the odd times it is exhibiting this when not overly hot, my first inclination is to say your valve lash is either incorrectly too tight, or is still set from the factory to North American spec.... and your "Georgia heat" is causing the lash to close up, especially after a hot run.

 

I would have the valve lash checked, and change them to "World specs" or even looser "Raceco specs". Do a search, or check out the Valve Adjustment FAQ for more details.

 

Many of us have had this problem and after sometimes MONTHS of fiddling and going back and forth to the dealer because our bikes wouldn't even idle when good and hot, it simply turned out that the North American valve lash settings(apparently set for EPA noise compliance - we assume) was in fact far tighter than the specs used for decades everywhere else on the planet, and once the engine was good and heat soaked, the valve-train was too tight to tick-over at low RPM.... exhibiting some of the traits you have described.

 

Now, that being said, this may not be your problem, but it's easy to check, and a good thing to make sure is right anyway.

 

Good luck.

al

[Guest Michael Derby]

Thanks you guys, as always.

 

I had a long good discussion with my dealer today. They are slammed with work, but made an appointment for the 16th. Here is sort of what we ran through.

 

1] Agreed with above that probably is not the map. As once it is set, it is set, and unless it was set way overly rich, he did not think that would be the cause.

 

2] Agreed with above that it is probably not the plugs. I grabbed them from the trash and will bring them to dealer to inspect, but using the standard OEM NKG and did not think that was issue.

 

3] One issue I may not have mentioned was that I have a bum "oil sensor light" it has been bum for about 3000 of my 4000 miles. It stays on at idle and then goes immediatly off when open throttle. Dealer told me not to worry and to bring by when had a chance and bring by and he would replace. Since I monitor the oil level and not excessive use or anything, and it is a pain to get bike to dealer (ask wife to drive me home) I let it go. Anywho the oil sensor light has not started to blink and go off when I do a hard acceleration. We discussed that maybe oil was seeping up into cylinder under hard acceleration and then causing it to have to "burn off" after. That is why it happens and then got better after nursing bike. He then started talking about issues involving oil etc. that was over my head.

 

4] Mentioned the valve's and adjustments etc. but didn't mention "lash" which is a term over my head anyways, but thanks and I am going to discuss that with him when I get the bike to him.

 

5] I had read about the "tank insulation suction" issue and thought about that. I looked under the tank and didn't see any issues or the insulation hanging down and left it at that. I am going to lift the tank tonight and see if the insulation is loose and that may be causing the problem. I guess juslt look to see if it is loose and getting pulled to over the airfilter when revved up correct?

 

6] What is "tank suck" ? I will do a search and see what I can find.

 

I will keep you all posted. Thanks for all this help, it give me a better understanding and gives me a sense of control to have my dealer look at different options instead of just taking what he gives me.

 

Wow - Owning one of these is completly a love / hate relationship isn't it. I have fallen so damn in love with this bike. To me there isn't another motorcycle as awesome as my Nero Corsa, yet what a pain in the ass having to deal with all the little bulls(*!@ issues. Is it possible to have this bike and ride 5 or 6k worry free miles and not have any issues come up, no matter how small?

 

Thanks

[jrt]

Agreed- it's probably not the map, but it's one variable. It's simple to check and that's why I suggest it (still do).

Valve lash is a better call. "lash" is synonymous with "space" or "distance" or "clearance". Set valve clearance to world specs as a general rule, I've found.

 

Tank suck is easy to see- the front end of the tank sucks in. You can look for it and spot it in a heartbeat. Open the gas cap and if it sucks...it sucks.

[Guest ratchethack]

Thanks you guys, as always.

Wow - Owning one of these is completly a love / hate relationship isn't it.

Por nada.

Not exactly. When you get into it far enough, even the hate seems like love.

Good luck!

[pete roper]

My advice, for what it's worth, is try a cooler plug. NGK's work the other way from the rest of the manufactures and i always get it wrong when I advise people and then they go Nyah-Nyah!!! So look at the NGK list and go one cooler

 

Pete

[emry]

My money is on valve clearence. My Scura was a fit to ride here in central GA with the OEM specs. I run the wide Raceco specs and the bike is sputter free and a joy. (Other than the darn dip at 4500 )

 

As for the oil sensor light, I would make sure that oil filter is properly seated. Didn't someone here have a similar problem and found that their filter had backed off. No oil pressure is very bad.......