[JasperST4]

OK, now what? I'm getting tired of this.

The engine starts and runs fine until about 170 degrees then it acts like it's got a bad plug wire or something and stumbles at lower rpms. Reving it makes it almost go away with just a hit of a miss. I don't want to ride it like this because it can die at the lower rpms.

I just set the TPS again, making no difference. The spark plugs are new, which doesn't mean anything but I don't suspect them because the higher revs make it better, not worse.

I'm guess a temperature sender, does that makes sense (before I pull the fairing off (again).

 

[JasperST4]

Never mind. I got her fixed. I went ahead and sacrificed a small goat in the back yard and poured the blood in the gas tank.

Actually it was the spark plugs after all. I didn't think it would be that easy, the new plugs only had about 200 miles on them. So at least one is bad, never bought a bad plug in my life!

Anyone have a good alternative to nonChampions?

 

[dr1445]

i am a fan off the ngk iridium plugs, did wonders for my st2 but then any new plug might have accomplished the same result. the .030 gap is going to give a longer spark than the .024 with the standard plug. might last a little longer too.

 

[Stick]

If it does act up again, just unplug the temp sender on the vertical cyl. water plumbing.
This is the one that feeds the ECU (the H. cyl. feeds the temp gauge). This will make the ECU think that the engine is cold, and leave it in the enrichened (start) mode.
But at least it should run consistantly with no stumbling. Be careful, because the fan will never turn on when this one is disconnected (it's fine if you're driving/moving above 40mph).

 

[tonered]

I've had a great run with standard NGK coppers over the past 10yrs on a car that uses the plugs ionization current to detect detonation know. Pretty crazy stuff.

I've run two sets in my ST4 so far (part number DCPR9E / stock number 2641). They seemed to work as expected. I don't remember which plugs were in the bike from the PO. The first set I installed came out quite rounded after 6,000mi.

The only other option for the NGK is iridium. I'd like to try them and since we only need two, it wouldn't be the worst loss, but the coppers seem to hold for at least 6k.

Have a good one.

 

[JasperST4]

Yeah, I'm going to go the Iridium route, I had originally ordered them from Ducati Seattle but the larger socket size wouldn't allow for the socket. But I've read some people use them so they must be available in the smaller size.

Shazaam had a good write up a while back...
http://www.ducati.ms/forums/showthread.php?t=31417

 

[tonered]

I've seen that one. Shazaam's stuff is always good.

For me, just as it is on our car that uses NGK copper, I just replace the plugs at each oil change. 6k seems to work for the Duc, 10k for the car. For some reason that just works for me.

I usually stock up on a good web deal.

Have a good one.