PLEASE HELP !!!03 monster dies when temp reaches 130

[moto-medix]

Thought it was the fuel system...pump was screaming...fuel looked like chocalate milk...fixed all of that...bike runs good when cold...as soon as the temp starts to register the motor starts bucking..wont rev...dies! please help?

[Slide Panda]

Let's go back a step - Why did fuel look like chocolate milk?

[moto-medix]

Thanks for the Quick reply...I dont Know...this is a customers bike and when we heard the fuel pump screaming we investigated and found what looked like mud in the tank...and lots of rust...so we cleaned and treated the tank...made sure all the air passages and fuel passages were clean and open...installed a new pump and filter and lines...and clean fuel (kreemed tank) Now the bike will idle fine and rev fine until it gets warm then starts spitting and after closer examination it is backfiring into the front cyl intake. My next step is to get an education on the desmo valve system...i am guessing that when the engine is getting warm the clearences are to loose? any help would be GREATLY appreciated. I have worked on bikes all my life and this is my first attempt at ducati...LOVE the engineering...in theory this should be  a nice machine. thanks again...Ray

[needtorque]

So it's an 03'.  M620, M800, M1000, S4?  Check the valve clearances I guess, maybe the rings are starting to wear and when the temps go up and things expand oil is getting past.

Try a compression test which should be done when warm so get it as warm as you can then run the test.  Replace the fuel lines if you only cleaned them.  I hope you replaced the fuel filter but dont want to assume since you did not state it.

[ducpainter]

Thanks for the Quick reply...I dont Know...this is a customers bike and when we heard the fuel pump screaming we investigated and found what looked like mud in the tank...and lots of rust...so we cleaned and treated the tank...made sure all the air passages and fuel passages were clean and open...installed a new pump and filter and lines...and clean fuel (kreemed tank) Now the bike will idle fine and rev fine until it gets warm then starts spitting and after closer examination it is backfiring into the front cyl intake. My next step is to get an education on the desmo valve system...i am guessing that when the engine is getting warm the clearences are to loose? any help would be GREATLY appreciated. I have worked on bikes all my life and this is my first attempt at ducati...LOVE the engineering...in theory this should be  a nice machine. thanks again...Ray

Yeah he put in a new filter.

[needtorque]

sorry read right over that. 

[Howie]

You might want to check the spray pattern on the fuel injectors.

[Slide Panda]

Yeah, I mulled this over and I'm thinking there's a fuel deliver issue.  You know that the tank contents were all fubar so I'd be wondering if gunk got down into the throttle bodies/injectors

[moto-medix]

investigating valve clearences...after that i will do compression check...should have done that earlier...duh...what is the correct amount of compression? fuel system is clean start to finish...is there a way to check injectors without a million dollar tool? Thanks again...Ray

[Slide Panda]

What year/ model is this one? 

[moto-medix]

sorry...its an 03 monster 620 IE DARK

[moto-medix]

ok...set up front cyl to tdc...checked opener clearances...intake .010 .254mm LOOSE? exhaust .oo5 .127mm correct?   spun motor 360 degrees and checked clearances again...Intake   .013  .330mm  LOOSE?  exhaust negligible but spins freely.  Correct?   NOTE...i read that you should push down on the closer fork to take the closer reading...I could not get any movement on the forks...intake or exhaust on the front cyl.   NEXT I set the rear cyl to TDC   checked the openers  Intake   .005   exhaust.005   correct?   spun the motor 360 and pushed down on the forks...this time getting a slight movement and measured again   intake.005   exhaust .007  which subtracting the original readings should put both within specs if i am doing this correct.  I got this method online from sport rider magazine. from what I can deduct...the intake valve on the front cyl needs tightned up with different shims. does this sound like it could cause the bike to act up violently when it warms up?   Please tell me if i did this wrong...I will await your reply before tearing down to measure shims. Thanks again..Ray

[redial]

these specs + commentary are from ducatisuite.com


These are the valve specs for the 2v engine (Monster, SS, ST2 etc.)  Note that these are on the tight side, it wouldn't
hurt to keep them on the high side (.004" for the intake openers, .005" for the exhaust openers,  and .001" for the
closers).  A clearance of .000" is possible, but very hard to obtain.  .000" is a condition where there is no difference
between the loaded and unloaded gap.  You cannot fit a feeler gauge in between the closing rocker (bottom) and the
closer shim, but can still turn the closer shim with your finger.

Intake openers:       .003"-.004"
Exhaust openers:    .004"-.005"

Intake closers:        .000"-.001"
Exhaust closers:     .000"-.001"

NOTE: 4v motors have a whole different set of clearances, on the looser side of the 2v.  I am only listing them here as
reference.

Intake openers:       .003"-.005"
Exhaust openers:    .005"-.007"

Intake closers:        .000"-.004"
Exhaust closers:     .000"-.004"


in the article he says that you dont need to worry about closers until .0015"
im not sure what the acceptable tolerance for openers is

[Howie]

Your valve clearances are no off enough to cause your problem, though they should be adjusted.  Minimum compression should be about 120 PSI, normal is 130 - 160 PSI.  I would like to see less than 15% between cylinders.  Do keep in mind, since your engine is only getting up to 130^o you may read a little low.  Also, make sure you hold the throttles open and disable the fuel injection (pull the relay).  You should also check fuel pressure, unfortunately I don't remember the spec.  This also requires special equipement.  I assume you checked all the fuel hoses?

To check injector spray pattern you would need to remove the injectors with the fuel hoses attached, hold them in a beaker, crank over the engine and watch the spray pattern.  The fuel pattern should be cone shaped and well atomized with no dribbles.  Unfortunately, I don't think there is an official Ducati volume spec.  You would want a competent helper since you are dealing with a highly flammable finely atomized product.  This is probably why there is no volume spec.  Most manufacturers shy away from this test procedure as factory authorized.

[needtorque]

I want to say the pressure is supposed to be like 45-50 psi but I cant remember exactly.  It was in bar in the service manual I think and I had to convert it to psi but that was 3 years ago while doing a project.