Dirty plugs with PC III

[Craig]

I have now had my Ballabio for about 2000 miles. It is mostly stock except for exhaust and a PCIII. This weekend I set about to do my annual maintenance. The plugs were very carbonized with a tighter gap than spec. Is this carbonization to be expected with a PC III? If not I guess I need to learn how to tune the thing, the carbon buildup seemed extreme, and I am no shrinking violet on the throttle...

 

Then again, I have no idea how long they were in there. The bike does seem to run nicer with the newer proerly gapped plugs.

[stormsedge]

I've not had carbon build up with mine.

[Tom M]

Plugs are cheap. Throw in a fresh set then see how they look after a few rides. If they're crusty again there are lots of possible causes. If the TPS is off it could be running rich. A dirty air filter will make it run rich. An incorrect PCIII map could make it run rich. Excess oil in the combustion chamber will leave residue on the plugs and in the combustion chamber.

 

I'd suggest that you check the air filter and if that's OK you might want to bypass the PCIII and see how it runs and how the plugs look. Finally you might want to check the TPS. It should read 525-530mV at idle with the key on engine off. Instructions on how to take the TPS measurement are in the how-to section.

 

If you don't mind doing your own work sooner or later you might want learn to do a full tuneup yourself. It's not very hard to do.

 

Hope this helps...

[Craig]

If you don't mind doing your own work sooner or later you might want learn to do a full tuneup yourself. It's not very hard to do.

 

Hope this helps...

 

I actually insist on doing my own work. I adjusted the valves yesterday, but aside from balancing the throttle bodies there doesn't appear to be much 'tuning' to do...its not like I need to set the timing and the dwell on an points distributor...

[Tom M]

There are instructions pinned at the top of the FAQ on how to set your TPS, adjust the air bleeds and balance the throttle bodies which, along with a valve lash adjustment, is what passes for a tuneup on these bikes.

 

I've had good luck with a simplified version known as the "Micha Method":

 

Step one - Set your valves to world settings (.15mm/.006" intake, .2mm/.008" exhaust)

Step two - Set your air bleed screws to open 1 full turn

Step three - Synch throttle bodies at just off idle (around 1800 rpm)

Step four - Set idle to 1100 using left idle screw adjuster only

Step five - Set TPS to 3.6 degrees (530mV)

Step six - Ensure idle trim is set to zero. This requires an AXEONE dealer tool or VDST software.

 

Once you've done this the only other tuning that you can do is change your PCIII map. A dyno run with an exhaust analyzer will tell you if your current map is in the ballpark for not much money.

[Craig]

There are instructions pinned at the top of the FAQ on how to set your TPS, adjust the air bleeds and balance the throttle bodies which, along with a valve lash adjustment, is what passes for a tuneup on these bikes.

 

Thanks, I'll look for those. I set my valves to the specs 0.10mm intake and 0.15mm exhaust. Sounds like the real world disagrees?

[Tom M]

Thanks, I'll look for those. I set my valves to the specs 0.10mm intake and 0.15mm exhaust. Sounds like the real world disagrees?

 

Yes. A lot of guys have had "flame outs" or stalling with a hot engine when running .10/.15 valve lash. Supposedly the .10mm int/.15 exh was the spec for US bikes only, possibly to meet noise regulations. Guzzi spec'd .15/.20mm for the rest of the world and not surprisingly it works here too! Some guys run .20/.25 (.008"/.010")in really hot or race conditions.

[luhbo]

Just for the files: the manual of my Euro 2000 V11 says .15/.10, so these are not US only specs.

 

Hubert