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Can I Adjust My Idle RPMs? My bike idles low at start


vinnie

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The bike has 37k miles and the valves should be okay. 
Should?... Meaning that they have never been checked?
 
Wait... what?
 
Vinnie, there's NO basis that I can think of for that argument. Go get your valves checked and adjusted before you do anything else. Otherwise you will be wasting time, money and energy at finding a a solution to what (might be) a problem before you have a baseline of your bike being up to date on maintenance.
 
Sorry to be harsh but that's my opinion.
 
And no, the idle is NOT adjustable on any YCCT Yamaha machine. There are several reasons the bike might be reluctant to idle, start with the simple stuff first.
 
-Skip.
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Should?... Meaning that they have never been checked?
Wait... what?  
Vinnie, there's NO basis that I can think of for that argument. Go get your valves checked and adjusted before you do anything else. Otherwise you will be wasting time, money and energy at finding a a solution to what (might be) a problem before you have a baseline of your bike being up to date on maintenance.
 
Sorry to be harsh but that's my opinion.
 
And no, the idle is NOT adjustable on any YCCT Yamaha machine. There are several reasons the bike might be reluctant to idle, start with the simple stuff first.
 
-Skip.
Yea, they have been checked and adjusted already. They should still be good. I should have added *still* be okay in my original post.
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  • 3 weeks later...
I'm still not sure what it means to clean the throttle plates. However, the problem seems to be getting worse. It's only after starting it when it's cold. It usually fires up immediately after, but last night, my bike stalled at a stop sign and took about 4-5 seconds of holding the start button to get it fired up.
 
I ran Seafoam through a tank last week, which I rode through in one day, and no changes there.
 
I am going to put a new air filter (almost ready to put one on anyways), new spark plugs, and do a compression test while I'm in there. 
 
 
 
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Sorry you are still having issues. Please post the results of your compression test. Bear in mind, that with YCCT the throttle plates may not stay open even if you are giving it full throttle while cranking the engine. So to get an accurate compression test you’ll need to manually open them up.
 
If you pry open the throttle plates and see a lot of black/dark residue on either side of the 3 throttle plates and the inside of the throttle bodies - that means you should clean off all that gunk (usually carbon buildup).
 
Then you will need to reset the “learned idle value” in the ECM which must be done with the dealer software.
 
-Skip.
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What is your idle RPM, engine hot and cold? Is your engine RPM always higher when cold? Does it have a consistent idle when hot? Have your resynched throttle bodies recently? A complete basic tune up is a good place to start. If you plan on trying to fix it yourself, you must get a factory service manual. If it dies when cold, look into what ever mechanism the FJ 09 uses to increase idle when cold. If it dies when hot, look elsewhere. Unfortunately, I seem to have forgotten more than I remember, so I am not sure if the FJ 09 has one, but there is something called a stepper motor that kicks in when engine is cold to increase idle.
 
 
Google how to clean throttle plates (or throttle bodies), lots of videos out there, even if not about FJ 09, you will get the idea. 
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Xlxr- the ecm uses the stepper motor to control the amount of airflow by opening and closing the throttle plates in the throttle bodies. That’s it.
 
The only adjustment is resetting the value I discussed above, and cleaning the throttle bodies.
 
There are contributing factors as well (tight valves, vacuum leak, water in the gas, poor spark, etc.) to whether the bike will idle.
 
Google YCC-T for a good explanation. It’s been used by Yamaha since 05 or 06 IIRC.
 
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