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Discussion Starter · #1 ·
First, I've spent the better part of a month scouring the inter webs and doing garage level diagnostics on my 749s.

Background. Bike has been sitting for a while (like almost 8 years, while)

Before it was set away if had the following done:

ECU flash with full system
Oil Service
Fork rebuild
brake service/flush

She ran fine when she was put away.

ME(bonehead) didn't fill or completely empty gas tank
fast forward to last year, get a hankering to get back on it. Doesn't start... fuel system is the problem, was getting ready to move so bike is back to the shelf to wait for a while.

New place, tear down to frame to clean and diagnose.

Bike is back together with new fuel pump/filter and donor tank while old one is cleaned and checked.

Bike starts but the top cylinder is cold and engine sounds like crap. Oil pressure light is on constantly while 'running'. Neutral light being weird.

Attempted actions:
Spark plug replaced
swapped coils (still cold on top cylinder so both coils are good)
checked all wiring goes were its supposed to via shop manual.


additional environmental considerations:
Bike sat without power for a long time
Never outside.

attaching a link to video w/ start up and engine sounds. https://www.icloud.com/iclouddrive/0gXjxMIswPClmJuxmP8_aFIiQ#IMG%5F2131

Thanks for looking this way, if I missed a thread in my searches that address this please direct me there.
 

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Take one air tube off and with a strong light see if the offending cylinder is getting fuel from the injector. But before you do that ground a good spark plug to earth and check for spark. It will be one of the other.
 

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Mostly full of S***
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Discussion Starter · #3 ·
...aaaand he's a genius.

No fuel to read cylinder and the front nozzle isn't spraying properly.

at least it's not a bad ECU...yet.

You think I can clear the hoses/nozzles or is it time for a new ones?
 

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Now for a little work. Airbox cover off and swap injectors. No need to pull them out just unplug, take injector/stacks off, reverse and plug back in. This will tell you if it’s an injector fault.
 

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Injectors are cheap enough to replace or you can send them out to be checked and cleaned. Personally I’d check and clean.
Note. At cranking speed the injection just dribbles fuel in. Idle speed is a spray/dribble and at 1500rpm should be a nice thin spray.
 

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Discussion Starter · #6 ·

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Seriously, wouldn’t waste my time. When you see the violence that happens to the fuel when you open the butterflies a teeny bit you will see that you can’t atomise it any more and the anecdotal evidence doesn’t measure up the the dyno evidence that I’ve seen. If the thing has been mapped well from the start then just stick to stock.
 

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iwp043 is for a monster 2v, not 749. they run the yellow band iwp069. i'd get some from the 848/1098 series - iwp189, pink band. they work nicely.
 

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Discussion Starter · #9 ·
If I purchase the iwp189s are they a direct fit? Will mapping or any other changes need to be made?
 

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the iwp189 do flow more in dynamic tests, but i have fitted them to 749 before and they seem to work very nicely.

they have 12 holes, compared to the iwp069's single hole.
 

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Discussion Starter · #11 ·
I think I owe a follow up for those who contributed their time and knowledge to my problem.

All is well, I got a pair of new injectors and the bike fired up immediately and sounds as it should.

Still having a oil pressure light steady on so I'm going to get the oil pressure switch replaced. (Oil dissapears on start from the oil level window.)
 

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Good to hear. Have you checked that you haven’t mixed up the neutral and oil pressure plugs. Both use a single pin plug and have seen people plug the oil pressure wire into the neutral plug.
 

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Discussion Starter · #13 ·
Funny you mention this, as I was coming on here to exclaim to the world that I'm not qualified to work on motor vehicles... This was exactly my problem.

Now if I could just get rid of the built in, ducati must be trolling, not really fixable, hesitation at 4k under heavy throttle...

Thanks again xracer!
 

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The easy fix is to keep above 5000 rpm and don’t give it a fistful under:)
A long shot. Do a minor tune as per Ducati service manual, tps, balance etc. Was this problem present before the rebuild?
 

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Discussion Starter · #15 ·
Affirm. The complaint was more tongue in cheek, obviously ripping on the throttle below 5k is for the noobs.
 
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