Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > For Ghosty / Kev / anyone DD Mechanic. question 2

[ells]

Originally Posted by Ghost

Carb diaphragm not lifting properly, needle dislodged. You have 2 pickups one for each cylinder.

I did have a sneek peak at the carbs and all appeared well. Will look again.

Will be looking at the wiring again

Many thanks.
M

[ells]

Well,
got some time this morning to have a look

igniters and coild redults seem to match on both sides

Coils (Dyna coils marked 5 ohm 0409 4+)
Coil (gear side) primary is 5.7 ohm
Coil (brake side) primary is 5.9 ohm

Igniters (DP AL9000 release 6.6)
measured on the pins on the igniters not the feed wires
gear side - infinate resistance
brake side - infinate resistance

feed to igniters (the plug that goes on igniters other end is in the engine)
gear side - 97.4 Ohm
brake side - 97.4 Ohm


All above readings were done with ignition off

Carbs.
I have had issues before with diaphrams (no s******ing at the back) on high mileage suzukis where they have deteriated through age and use. So stuck my fingers in the carbs and gently teased each side up and down (no s******ing) and all felt nice and smooth and both reacted the same.

So I started her up and stuck my head down to have a good look, nothing different about either slide both go up and down ok.


Odd things I noticed.
The wire from engine to igniters is clamped tightly at two points to the frame and the yellow and white wires to the brake side igniter looked like they had seen better days. I gave them a good manipulation while they were attached to the multimeter to see if the readings moved when they were wiggled.

As before only seems to have started the issue when warm but seems to be deteriorating as well.

If I get time I wil look at coil leads. It may end up either not going to Wales or going to a shop. As it only occurs when warm and under load its going to be difficult to trace.

Mark

[ells]

Gone to shop now, hoping its nice and easy (cheap). Hey ho. Quick call now for a set of tyres. Now I am understanding why racing aint cheap.

[skidlids]

Wondering what the air gap is on the ignition pick-up coils. Also be interested if there reading changes when they are hot after running the engine for a period of time. At 97 ohms they are already a bit on the low side

[ells]

Originally Posted by skidlids

Wondering what the air gap is on the ignition pick-up coils. Also be interested if there reading changes when they are hot after running the engine for a period of time. At 97 ohms they are already a bit on the low side

I missed the trick of letting the bike stand running to get hot and then re-reading the pick up resistance. Hoping it will be running AOK for Pembrey

[Ghost]

Today at Cadwell I was in the holding area, I noticed the idle revs were down from normal. Pulled the vert plug lead and the engine stopped. On part throttle it was running on 2 but not quite as crisp as it usually is.

Compression test revealed front pot 25psi down on the rear pot. So I took the head and barrel off, signs were running very weak. Then I found a large split in the carb rubber right under the Jubilee clip.

Better to find on a TD than waste a race weekend tho'.

Met a lot of faces today for the first time, good banter with everyone.

[paynep]

You'd think that with all these problems with 17 year-old wiring, diaphragms, mixture screws, igniters and the like, you would get more people out on the 9-or less year old 620s.......