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Discussion Starter · #1 ·
Hey everyone. Wanted to run this by you guys to see if anyone else has had this problem. 1000ft elevation

Carbs are all rebuilt, dynojet stage 2 kit
160 mains
40 pilot
3rd clip from bottom on needle
New emulsion tubes
CA cycle works ignition coils
Bike has spark but its not super bright and white. Kind of blue/purplish
DCPR8E plugs
120psi compression both cylinders
Leak down test on front cylinder was 80psi inlet and 78psi holding, rear cylinder was 80psi inlet and 72psi holding.
Both plugs are equally carbon fouled though. The float level is also set correctly based on another thread here using an external "meter" to read the level on the outside of the carb while in the motorcycle.

Any advice? Been fighting this thing for a while now.
 

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So have you lowered the needles ( higher notch ) ? Think simple first. Warm the bike up real well and adjust your mixture screws to just the point where idle hangs for a second before dropping, then ccw 1/2 turn and test ride . Another thing it could be : When you did the carbs did you replace the rubber gaskets between the carb body and the needle/seat holder , and also between the carb body and the main jet holder ? If they leak, unmetered fuel runs into the float bowls instead of through the seat and jets as it’s supposed to. You can’t tune a carb in that condition. Blue / purple spark is good, if it’s steady. Did you replace your wires and caps ? You need resistor wires or caps, but not both.
 

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Verify it is un burned fuel and not oil from guides/rings, put in fresh plugs and how soon does it turn black?

miles on bike?
fuel screw setting?
have you tested CO at tailpipe to determine if it is rich at low throttle or good at idle?
try feeding a bit of enrichener and if it runs okay with a bit added then it my not be the idle circuit. If it instantly kills it you may be rich on pilots,fuel screws,external fuel leaks as duc96cr mentioned. I have seen fuel screw seats damaged from owners over tightening screws as well as decel valve circuits being open after carbs were disassembled and reassembled incorrectly. And never rule out a enrichener plunger stuck open.

Is it one or both?
does it run okay?
how long does it take to make them black?
does it start cold with NO enrichener needed?
 

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Discussion Starter · #5 ·
Ive tried going up a notch and it was way too lean. Spit flames out of the exhaust then and coughed terribly. I would warm the bike and prior to setting fuel screws. Very familiar with that process. The orings in both spots looked in good condition but were not replaced so maybe that is my next step to try. Will replace then both. The wires and caps came with the CA cycleworks ignition coils.

So have you lowered the needles ( higher notch ) ? Think simple first. Warm the bike up real well and adjust your mixture screws to just the point where idle hangs for a second before dropping, then ccw 1/2 turn and test ride . Another thing it could be : When you did the carbs did you replace the rubber gaskets between the carb body and the needle/seat holder , and also between the carb body and the main jet holder ? If they leak, unmetered fuel runs into the float bowls instead of through the seat and jets as it’s supposed to. You can’t tune a carb in that condition. Blue / purple spark is good, if it’s steady. Did you replace your wires and caps ? You need resistor wires or caps, but not both.
 

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Discussion Starter · #6 ·
They used to turn black quick, after 10-20 miles. Then i bought new emulsion tubes and the dynojet kit and now its more like 100+ miles so it did improve a lot. Fuel screws are 3 turns out. With the enrichener on and fresh plugs, it works as it should. Once the plugs get fouled, the enrichener doesnt work as well. Almost need it on just to keep it running

Verify it is un burned fuel and not oil from guides/rings, put in fresh plugs and how soon does it turn black?

miles on bike?
fuel screw setting?
have you tested CO at tailpipe to determine if it is rich at low throttle or good at idle?
try feeding a bit of enrichener and if it runs okay with a bit added then it my not be the idle circuit. If it instantly kills it you may be rich on pilots,fuel screws,external fuel leaks as duc96cr mentioned. I have seen fuel screw seats damaged from owners over tightening screws as well as decel valve circuits being open after carbs were disassembled and reassembled incorrectly. And never rule out a enrichener plunger stuck open.

Is it one or both?
does it run okay?
how long does it take to make them black?
does it start cold with NO enrichener needed?
 

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Discussion Starter · #7 ·
do you guys happen to know the o-ring sizes for those? the seat/needle o-ring and the under-slide body o-ring?
 

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needle and seat one i use oem. under slide carrier one is not available oem, think it's m10 x 1.5.
 

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I wonder if you’re maybe leaving the enrichener on too long ? In most cases if the carburetion is right the bike will start with no choke at all or just start it and back off the lever to the point where it keeps running on its own for a minute, then off completely as soon as it can handle it. Assuming your pilot jets are correct you may need to adjust the mixture screws when the engine is very warmed up, like after a ride. Keep in mind there isn’t a certain prescribed spot to adjust them too, they will continue to control the idle mixture until at least 5 turns counter clockwise .
 

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I think there is one in the Haynes manual. If not, you can download the factory manual. I know I’ve seen one, I just can’t remember where.
 
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