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CrashTestDanny
09-12-2006, 11:46 PM
Today I decided it was high time I put my new Morgan Carbtune II (http://www.carbtune.com/) to work. My ST has been idling rough since about 10,000 miles (13,500 now) and it has caused the engine to die frequently when riding in traffic.

After extracting the three screws that I stripped the heads on, I removed the airbox and set up the Carbtune. Following the instructions in the service manual, I disconnected the starter valves' vacuum hoses from the 5-way connector under the MAP sensor and then ran the engine at 2k+ RPM long enough for the ECM to begin ignoring the MAP (10-15 seconds or so). Then I hooked the Carbtune up and idled the bike down. The right bank (2 & 4) were pulling about 50% of the vacuum that the left bank were. :eek:

A few turns of the wrench and I had all four cylinders drawing the same vacuum. Once the starter valves were sync'ed, the bike idled much, much smoother, all the way down to 600 RPM. I set the idle for 800 RPM and she's running beautifully, now.

The Carbtune II was easy to use and worked flawlessly. The price is slightly more than mercury sticks available elsewhere, but well worth it, in my opinion, since the Carbtune does not use Mercury and seems to be much more environment friendly.

nm6r
09-13-2006, 03:26 PM
I'm guessing you also pulled the hoses from the PAIR valves and plugged the fittings?

I also use the Morgan CarbTuneII. Certainly not the cheapest but it works, stores and transports well.

Hopefully you didn't overtighten the airbox screws this time around. I only snug them using two fingers on the screwdriver handle.

Ray
http://www.frontiernet.net/~st1300rider/smile04Bikerwheelie.gif

CrashTestDanny
09-13-2006, 05:29 PM
I plugged in to the hoses that are connected to the starter valves and all connect to the MAP sensor - as the service manual says.

Yeah, I tried not to over-tighten them. I couldn't get the right screws, so I found a substitute with no shoulder. It seems like the shoulder helps the screws to sieze. In any event, the shoulder does not seem to be vital to holding the funnel bases in place.

nm6r
09-13-2006, 06:06 PM
I was referring to the hoses on each valve cover that are apx. 3/8" id. The service manual says to also pull them and plug the fitting.

Ray
http://www.frontiernet.net/~st1300rider/smile04Bikerwheelie.gif