Heads rebuilt-Runs like nothing happened

[DesmoTillDeath]

Hello all,

So my princess of a grundle rumbler has struck again.
I just got my heads back from Speeddog and they are completely rebuilt.
I installed them with all the proper procedures in mind and torqued everything back down and took her for a spin.
The beast runs terrible still. Just as bad as when it had worn rocker arms and a cracked exhaust valve and a broken exhaust stud.

I'm thinking it is an issue with the ECU or fuel system.
I'm hoping to get down to Southern Cal Motorcycles for a trim adjustment next week.

There seems to be a loss of power, rough running, popping and backfiring under engine braking, especially at lower RPMs. And upon cold start up theres a "chug" noise that happens twice as the bike tries to start. Almost noises like a hiccup.

If anyone can think of anything that might be the culprit i'm all eyes.

-injectors
-throttle body sync
-ecu
-spark timing
?

[Monsterlover]

What do the plugs look like?

[brad black]

what is the cranking compression?
how much leakdown?
how much fuel pressure?
battery charging voltage?
voltage at coils and injectors?

[DesmoTillDeath]

Brand new NGK plugs.

How do I test fuel pressure?

[brad black]

with a fuel pressure gauge.

[DesmoTillDeath]

Okay heres what I got:

Cranking compression:           ~100psi both cylinders
Leak down:                         No audible leak. Used the Harbor Freight leak down tester setup and it read less than 5% leak.
Battery charging voltage:      I ran the bike at ~4000 rpm and the battery read 13.6VDC.
Coil voltages:                      Running the bike at idle both read ~3VDC each.
Fuel pressure:                     Didn't check the recommended operating pressure before buying gauge. Gauge only went to 15psi and It was pinned while bike was running.
Injector voltage:                  Not totally sure how to measure this.

What else are we thinking?
Maybe the injector/spark timing it off.
A trim adjustment is needed but I dont think it would run this bad if that was the only issue.

[koko64]

How'd you check cranking compression?
Warm motor, throttle Wide open?

[DesmoTillDeath]

How'd you check cranking compression?
Warm motor, throttle Wide open?

Exactly

[Ddan]

I think that's pretty low compression

[Howie]

Compression numbers and cylinder leakage don't seem to agree with each other.  5% is good, 100PSI is not.  I suspect either one gauge is off or valve timing off a bit if you have adjustable pullys.

[DesmoTillDeath]

I have the stock pulleys which do have slots for adjustment.
Does anyone have a source for the timing procedure?? I can't seem to find it in the Haynes Manual.

Otherwise that might be pricey at the shop.

Compression should be around 160psi correct?

[koko64]

Round about that, say even 150 according to Haynes. For reference I've seen 150 in a 750, 160 in a 900, 190 with hi comp and 200 with hi comp big bore.

[Speeddog]

Cranking compression should be somewhere close to 150 or so.

Fuel pressure should be 45psi.

I wouldn't put much meaning on HF Leakdown numbers.

[DesmoTillDeath]

So I found this article:

http://www.ducati-upnorth.com/tech/camtiming.php

I'm not sure If this is what I should be looking into but its a start.
Id be willing to get this looked at at a garage but its my only vehicle and thus tough to let go for extended periods of time.

This is also an interesting article:

http://www.ducatitech.com/2v/maint/rebuild/headwork.html

[Speeddog]

I'd say there's a fundamental problem.

Small adjustments to cam timing or port work to improve airflow aren't going to solve the problem.

Did you get a fuel pressure reading?