i have a 95 m900 i got as a basket case i got it running and when i ride it hard it it feels like runs out of fuel. this is what happens it starts great, idles great, and thottle response is great when i ride it slow,low rpms like 2000 it runs good. when i open the throttle wide open and take off in 1st gear pulls hard untill i get into 2nd then it dies out like no fuel intill i let off on the trottle then it comes back. i tried riding in 3dr gear at low rpms then roll on the throttle does the same thing when the rpms get high like 3000rpm. things i have done clean the carbs, new fuel filter, new fuel pump rebuild kit, new non vacume operated petcock and new fuel lines with no kinks.
does the fuel pump work from the intake vacume? thats how i have it and i think when it gets into high rpm it would be just a stedy vacume not a pulse like it needs to operate. is there any specs on the fuel pump like psi or flow rate? does the pump need to hook up to the crank case for a pulse like i have seen in the past with other bikes?
Are the plugs black?
It sounds to me like the slides are not lifting...
you've covered most of the other bases already.
The fuel pump is hooked up correctly. Like ducpainter said, start with pulling a plug. Any history on the bike?
Fuel line from filter in good shape, nice round bend on it?
Mine started to go soft in the middle, caused a thinner passage f fuel.
Symptoms just like yours.
Also check the fuel line from the pump to the carbs. They get soft and collapse.
Definate symtoms of fuel starvation, if the slides were not lifting, the engine would not rev much above 1K.
As others with FHE have said, check your fuel lines - that rubber has been in contact with fuel for 13 years.
Quote from: Capo on December 15, 2008, 11:54:57 AM
Definate symtoms of fuel starvation, if the slides were not lifting, the engine would not rev much above 1K.
As others with FHE have said, check your fuel lines - that rubber has been in contact with fuel for 13 years.
I have to disagree with your slide comment.
The slides in the cv carb are directly related to fuel delivery as well as air.
Most fuel delivery problems related to restricted flow appear after periods of high rpm operation as opposed to not ever running over a certain rpm.
Those aren't the OPs symptoms...My money is on the slides not operating properly.
You are correct, I'm 'pre CV' :-[
the plugs look lean and the fuel lines are new with no kinks and the slids are moving up and down with rpm i also checked for vacuum leaks none. the bike had been crashed so it ran good before the crash and the guy i bough it from was going to fix it and pulled it apart and lost intrest in it and sold it to me so i had to replace the frame and now im here not knowing what to do i just wont to ride it its my first ducati. the only other thing is that when i replaced the fuel pump kit it got a little better so thats why i thing its a fuel problem.
Quote from: motomike on December 15, 2008, 05:29:41 PM
the plugs look lean and the fuel lines are new with no kinks and the slids are moving up and down with rpm i also checked for vacuum leaks none. the bike had been crashed so it ran good before the crash and the guy i bough it from was going to fix it and pulled it apart and lost intrest in it and sold it to me so i had to replace the frame and now im here not knowing what to do i just wont to ride it its my first ducati. the only other thing is that when i replaced the fuel pump kit it got a little better so thats why i thing its a fuel problem.
Are you running an airbox?
yes i have an air box it has a k&n air filter but the lid has been cut out i guess for more air flow
Are you sure it ran right before the po crashed it?
Quote from: ducpainter on December 15, 2008, 07:08:03 PM
Are you sure it ran right before the po crashed it?
+1.
Also, make sure the diaphragms are fully seated all the way around.
If the top covers are off for a while, the diaphragms shrink a bit, and it's really hard to get them fully seated.
If you rev the engine with the air filter off, do both slides open similar amounts, and does it look like the same amount of fuel is coming out of the jets?
If the bike is backfiring at all... be very careful about looking down the carbs...
Quotethe plugs look lean
Just to b sure/isolate the problem:
Unhook fuel line into carbs. have a small container under hose, run starter a few secs.
It should pulsate quite freely.
If so = it's carb related, not fuel delivery.
so i found out that the fuel pump is working good. i took apart the carbs they are mikuni 132. i looked at the jets the main fuel jet is 70 and the main air jet is a 50 the needle is on the 4th clip from the top. doent look like the stock one maby it has a jet kit in it. the pilot fuel jet is a 40 does any one know if the jets i have are close to what i should be running and any one know how to identify my engine to tell what cc it is the title says its a 900 just wana make sure it not a 750 or 600 thanks.
If it's got a dry clutch, it's a 900.
Pretty sure that in '95, the M900 was all there was.
Quotei took apart the carbs they are mikuni 132. i looked at the jets the main fuel jet is 70 and the main air jet is a 50 the needle is on the 4th clip from the top. doent look like the stock one maby it has a jet kit in it.
If it is a 900 w open lid, it should be Mikuni 150/155 in there, 132 too small even in standard shape.
If needle is the thinner type like DynoJet, their corresponding jets should be 160-165-170. That`s what I got w my Stage II kit.
Quote from: motomike on December 22, 2008, 08:52:59 PM
so i found out that the fuel pump is working good. i took apart the carbs they are mikuni 132. i looked at the jets the main fuel jet is 70 and the main air jet is a 50 the needle is on the 4th clip from the top. doent look like the stock one maby it has a jet kit in it. the pilot fuel jet is a 40 does any one know if the jets i have are close to what i should be running and any one know how to identify my engine to tell what cc it is the title says its a 900 just wana make sure it not a 750 or 600 thanks.
If the jets are Mikuni or Factory Pro the numbers are way off, if it was kitted with DynoJet ummmm......even though I have DynoJet in my bike........don't know, they use different numbers for sizing.
If you want info from DynoJet try here:
http://www.dynojet.com/jetkits/contact_support.aspx (http://www.dynojet.com/jetkits/contact_support.aspx)
Out of the factory your bike had 140 main fuel jets, 150 air jets and and the needle was three from the top. The pilot numbers match. Jet kits were popular on the US versions because they ran lean.
Quote from: greenmonster on December 23, 2008, 03:49:32 AM
If it is a 900 w open lid, it should be Mikuni 150/155 in there, 132 too small even in standard shape.
If needle is the thinner type like DynoJet, their corresponding jets should be 160-165-170. That`s what I got w my Stage II kit.
I believe motomike was referring to Mikuni BDST 38 model B132, which is US jetting, you would have a model B129.
QuoteI believe motomike was referring to Mikuni BDST 38 model B132
OK,
but the my main jet sizes are correct.
I have a DynoJet stage 2 kit in mine with 165 mains with a swiss cheese lid.
Mikuni/DynoJet conversion chart (http://vmaxoutlaw.com/tech/dyno-mikuni.htm)
If the motor cuts out/off, wouldn't it point to something electrical? I would think that a carb problem would show as a bog or hesitation.
If the bike ran well before it was crashed, it prolly isn't jetting, assuming you kept the same slip-ons and airbox configuration.
I'd check first that the tank is venting properly. Check the rubber nipple under the gas cap by the hinge, make sure itsn't crinkled up, restricting the air vent flow. I'd also check the routing of the vent hoses. I've had mine crimped up after I pulled the gas tank up and it did the same thing your's is doing. Finally,
make sure you have the correct fuel filter. I installed a Fram filter on mine that looked almost identical to the factory filter, but had the gas exit on the opposite side. That routed the fuel line on the valve cover with enough pressure that when the bike warmed up, the hose would get soft and restrict the gas flow to the pump. Gave me fits finding that for ~ a month.
George
so i put in a 135 maine jet and left the air the same at 50 thats all i could get a hold of today and still doing the same thing. i also installed a clear section of fuel line that runs outside of the frame so i can see the fuel flow looks good no air bubbles. checked the tank vent its good im going to try to put in a 165 main fuel and see if that changes as far as the air jet i will have to order it. the fuel filter is working good i checked it out today. so my bike does have a dry clutch so its a 900 and that means that i should have a 140 main fuel and a 150 air. i just dont understand how a 70 main fuel and a 50 air got in there. thanks for all the help
is the main jet the large flat head screw type or is it the press in type? dyno jet says its press in and a screw holds it in place. i just making sure that some one dint lose the screws that hold in the press in jet and reaplaced them with jets and im thinking that they are the main jets.
The press in, held in place with what may look like a screw holding the retaining plate, but is actually the starter jet.