High Idle Speed on Muffs - Normal?

[JoLin]

1997 Johnson 175 - carbed

I'm still new to this motor and except for decarbing and winterizing it last fall, I haven't really run it. I also can't remember how it acted last fall. I searched but was unable to find anything on this topic.

I de-winterized it yesterday and, according to the tach, idle speed at operating temp is 2200-2300 rpm. Is this because of no back pressure on the exhaust, or do I have a problem with the motor or tach?

On the other hand, it starts and runs with very little coaxing when cold, and instantaneously when warm. Operating temp is steady at ablout 175 degrees. There doesn't appear to be excessive smoke, tho I don't have any firsthand basis for comparison.

Your thoughts?

 

[tashasdaddy]

Re: High Idle Speed on Muffs - Normal?

2200-2300 is very excessive, should not be more than maybe 1000. does this motor have the fast start feature?

 

[JoLin]

Re: High Idle Speed on Muffs - Normal?

If you mean "QuikStart Electronic Starting" (cold engine timing advance), yes it does.

 

[Solittle]

Re: High Idle Speed on Muffs - Normal?

175 seems a bit on the warm side. When did you change the water pump?

 

[JoLin]

Re: High Idle Speed on Muffs - Normal?

Water pump was rebuilt last fall. Note that tell-tale is strong, temp holds rock steady, and I've run it for up to a half hour at a time. I'd think if there was an issue it would eventually overheat.

 

[JoLin]

Re: High Idle Speed on Muffs - Normal?

One other item of note- after I first started the motor on Wednesday, I changed the plugs and it wouldn't restart. Looking around, I found a broken wire right at the connector between the left bank temperature switch and the wiring harness. I had to snip out the connector and wire up directly using heat shrink butt connectors. I was careful to wire tan to tan and white to white, and the connections are solid. After reading Tashasdaddy's question and browsing the shop manual....

Could the broken connection have shorted/fried the temp sensor?

Would an inoperative temp sensor on one cylinder bank cause this issue by screwing up the QuikStart feature?

 

[JoLin]

Re: High Idle Speed on Muffs - Normal?

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[JoLin]

Re: High Idle Speed on Muffs - Normal?

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[tashasdaddy]

Re: High Idle Speed on Muffs - Normal?

i don't know, sorry.