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Discussion Starter · #1 ·
I have noticed lately on my 78 RR Shadow (17,000 miles) the engine will not speed up when I start from cold. I press the accelerator before starting the engine. Until now, it would start immediately with the fast engine speed. Now, I have to restart it a few times before the engine will catch & speed up. After it starts up & idles fast, it is perfect: will cut back to idle speed when pressing the accelerator. Super smooth acceleration. Just doesn't want to start immediately with the fast idle when cold. Any help appreciated.

Richard
 

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Discussion Starter · #3 ·
UPDATE

The linkage was fine. The weather in North Carolina has been warmer in the past few days; the RR has started up perfectly. I am assuming the choke has to be adjusted to deal with the colder temperatures we have had this winter?

Richard
 

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Richard

Yes these cars do not fair well in frigged temps like we have had recently. You may need to adjust the choke to a winter setting. It might help.
 

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You might want to check that your Scintilla switch is working. It's a little device that holds the choke closed with a solenoid when the temp is frigid. It contains a little winding which heats up from battery voltage and switches it back off after a couple of minutes.

The choke is in the aluminum air intake pipe (between the big air intake hose and the Y for the two carbs); you'll see two small electrical wires coming out of it which feed the solenoid.

The Scintilla switch is a round bakelite thing mounted on the firewall next to the A/C relays and Otter switch (under the trunking between the fan and the A/C evaporator box). It's on the RH side in a RHD car; not sure about a LHD one.

Jeff.
 

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I know that this thread is very stale, but I thought I'd add several things:

1. Jeff's description of the scintilla switch - it's appearance, function, and location, are the best I've seen anywhere. This thing is woefully undocumented other than in the electrical diagrams.

2. Scintilla is the brand marked on the plastic/bakelite housing, which is round, and to which there are three connections. The very brief mention of this switch in the workshop manual refers to it as the thermal delay switch.

3. It is located on the right side of the car tucked under the blower fan and duct work on both RHD and LHD cars.
 
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