cold high idle
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Seasoned HDF Member
Joined: Oct 2012
Posts: 11,216
Likes: 3,045
From: St.Louis Mo.
cold high idle
my 15 jumps to 2500 or maybe even to 3000 rpm's when first started cold. it comes back down to 1500 or so pretty quickly though and when fully warmed it's about 1000. this just seems hard on a cold engine. i don't believe my 12 jumped to such a high rpm when cold. anyone else seeing this or am i just paranoid about nothing. i wish there was a way to tone it down abit . 
Seasoned HDF Member
Joined: Sep 2009
Posts: 25,306
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From: Eastern NE
I know w/my '09 the TPS would get "squirrely" if you shut bike off before it hit normal idle (when hot). I just wait until she drops & the problem never repeated...don't know if this is the same w/newer Rushmore's...probably not.
Road Master
Joined: Jan 2016
Posts: 1,143
Likes: 433
From: Menifee, CA
2500 to 3000 rpm at cold startup seems way too high to me. My 2016 cranks to about 1300-1400 rpm cold. Within a minute it starts settling down. I think there is something wrong with the OP bike.
On the old carb'd engines, choking to max could make the engine run to near 3000 rpm, but we never let it go that high. We set the choke for a lower warmup rpm because, wow, 3 krpm is just plain to fast to idle a bone cold motor.
I would have this checked out.
On the old carb'd engines, choking to max could make the engine run to near 3000 rpm, but we never let it go that high. We set the choke for a lower warmup rpm because, wow, 3 krpm is just plain to fast to idle a bone cold motor.
I would have this checked out.
Thread Starter
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Seasoned HDF Member
Joined: Oct 2012
Posts: 11,216
Likes: 3,045
From: St.Louis Mo.
it does jump to 2500 and maybe alittle higher ,but comes right back down to 1500 or so until warm and then it's at a 1000. i just think it's alittle high for a cold engine. i'll pay attention to some other bikes next time i'm out. thanks !
Tourer
Joined: Oct 2015
Posts: 391
Likes: 52
From: Pittsburgh, Pa.
2500 or 3k rpm on a cold start doesn't sound right to me. Mine used to go right to 1500 on a cold start and I didn't like that so I turned the cold idle speed down to 1100 with my FP3 and left it there, no troubles stalling or anything. The reason I did it was because my bike sits for a while sometimes and I don't want the engine idling so fast until the oil gets pumped around some first. I usually let it warm up for a minute before I take off also. My normal idle speed is set to 1000 so once it drops to there from 1100 I know I can safely twist the grip hard if I want without any worries.
Was your bike on a jack or the ground? The reason I ask is one time I had mine on the jack after doing some work and started it and wondered why the idle was so fast and wouldn't settle down .... well, it turns out because I over-looked the rear wheel was spinning (yes, it was in neutral) on a cold start was enough for the VSS to make the ECM think the bike was moving. Once I hit the brake and stopped the wheel the idle calmed down. That one messed with me for a bit til I figured out that something so stupid as the wheel turning could screw with the idle speed.
There are different tables for idle speed at certain temps and also whether the bike is in motion or not until the bike is at full operating temp. That is the other reason I lowered all the cold idle speed temps to 1100 so you don't have that "hanging" idle effect when riding off immediately after a cold start. I mentioned above that I warm it up for a minute, but that's only if the bike has sat for days or weeks or the first cold start of the day. After that I will start it up and ride off easy til it's up to temp again and it no longer irritates me with an idle too fast to grab gears when cold.
Was your bike on a jack or the ground? The reason I ask is one time I had mine on the jack after doing some work and started it and wondered why the idle was so fast and wouldn't settle down .... well, it turns out because I over-looked the rear wheel was spinning (yes, it was in neutral) on a cold start was enough for the VSS to make the ECM think the bike was moving. Once I hit the brake and stopped the wheel the idle calmed down. That one messed with me for a bit til I figured out that something so stupid as the wheel turning could screw with the idle speed.
There are different tables for idle speed at certain temps and also whether the bike is in motion or not until the bike is at full operating temp. That is the other reason I lowered all the cold idle speed temps to 1100 so you don't have that "hanging" idle effect when riding off immediately after a cold start. I mentioned above that I warm it up for a minute, but that's only if the bike has sat for days or weeks or the first cold start of the day. After that I will start it up and ride off easy til it's up to temp again and it no longer irritates me with an idle too fast to grab gears when cold.
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Extreme HDF Member
Joined: Jul 2015
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From: Edmond, OK
The combustion process is very hot. It takes probably just a couple strokes to be hot enough to not cause problems. Even though the temp outside is low after just one explosion that cylinder is hot already. Trust the EFI and enjoy your bike. All is well.
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From: Toledo ohio
Look on top of your throttle body, there should be a rubber cap on top of an emission nipple. This nipple is for some kind of Cali emmisions (fake global warming smog hype) Mine blew off one time on a backfire when idling. Your bike will try to compensate for the unmetered air.
