Hanging idle. Everything else is perfect?
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    Hanging idle. Everything else is perfect?

    by Bill93 » Mon Oct 24, 2016 12:38 am

    My bike is a 2006 CRF 250R I built with an 05 bottom end with Wiseco internals, all new tranny bearings, Wiseco top end with a 07 head from here and a stage 2 cam in it.

    When it first went together I had some issues getting it started which I worked out with a ID jetting kit. Bike starts first and second kick even after sitting for a month. The only real issue I have is that the bike has a hanging idle. I was wondering if a worn out needle seat/tube could cause this. I didn't replace it and have no clue if the previous owner ever did either. The bike doesn't have any noticeable or barely any bog with a wop pull and doesn't hesitate or stumble. Just has that obnoxious hanging idle. Also slow rides in gear below it's hanging point perfectly fine. I messed with the pilot and main with the fuel air mixture and got it to drop a bit but it's still idling ~1100 rpm

    Thanks!
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    by Aussiecrf230 » Mon Oct 24, 2016 5:54 am

    I assume the throttle cable is returning OK and has some play to allow for steering. Sometimes the cable can go back in a bit tight and cause this problem.

    Can you get to idle slower or is it constantly idling high?
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    by Bill93 » Mon Oct 24, 2016 10:02 am

    When I installed the new cables I double checked all that and had proper slack full lock and straight ahead. Went out and double checked to make sure. Everything seems good.

    Any other ideas as I'm stumped.
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    by Back2-2 » Mon Oct 24, 2016 12:07 pm

    As long as you hear the slide inside the carb body "snapping" when the throttle snapped the only other thing that comes to mind is possibly an air leak around the carb boots ? That can lead to hanging idle symptoms. That can be checked with some WD40 or starter fluid sprayed around those areas while running. If the idle jumps up it means an air leak is present and ingested the spray.

    Hope that helps a little.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    by Bill93 » Mon Oct 24, 2016 1:17 pm

    Slide does snap back instantly. So I'll check for air leaks tonight.
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    by Aussiecrf230 » Tue Oct 25, 2016 1:05 am

    Hot start not fully closed would let extra air in as well.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    by Bill93 » Sat Nov 26, 2016 9:13 pm

    I ended having life get in the way and lost time to work on the bike. Found some time over thanks giving and ended up playing with the Fuel screw and determined I needed a bigger pilot after pilot and had to just ignore my instinct that at a 52 pilot it still needed a bigger pilot. The biggest pilot I had on hand was a 55 and everything is running perfect but the Fuel screw is 3.5 turns out. So I'm waiting for the 58 pilot to come in which should be pretty damn perfect. This seems really big to me but I guess I do have a high compression piston, fmf mega bomb & 4.1 exhaust. But factory for my elevation is 42. Seems odd id need a pilot that much larger. I considered messing with a different pilot air jet size on the front of the carb to attempt to use a smaller pilot.

    Thoughts?
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    by Aussiecrf230 » Mon Nov 28, 2016 3:49 am

    So is putting the larger and larger idle jets in lowering your idle speed? It sounds like you are increasing the amount of fuel going in to compensate for an air leak.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    by Bill93 » Mon Nov 28, 2016 6:34 pm

    once i got to a 45 pilot the idle was the same with the 45 48 50 and 52, but the Fuel screw went from falling out to 4 turns out and running super smooth. I also checked for air leaks spraying carb cleaner around the boots with no change in rpm.

    Installed a 62 pilot today and it was too rich so it looks like I'm going to need a 55 or 58. Just seems really high over stock. But if the bike runs proper, then I guess that's what it needs.

    Bike has a full fmf exhaust and mega bomb. Running a K&N high air flow air filter. Looks like a previous owner removed the anti-fire screen which prevents the filter catching on fire. It does have a Wiseco 12.5:1 piston in it. I was expecting like 45/48 over the stock 42 for my elevation. Also time to put the JD Jetting cold needle in. So I'll do that and wait for the assortment of jets I ordered and see what happens. I'll Be sure to update this with my findings.
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    by Bill93 » Tue Nov 29, 2016 8:52 am

    UPDATE:

    Installed the blue (Cold) JD Jetting needle, AP mod, and installed a 55 jet I found hidden in my collection and it ran butter smooth @~800 rpm 3.5 turns out on the Fuel screw. So following the .5 turn per jet size I should need a jet 4 sizes larger for 1.5 turns on the Fuel screw. Since that's a 59 and I can only order a 58 and 60 I'll probably order both and see which one gets the job done.
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    by Bill93 » Tue Nov 29, 2016 5:19 pm

    UPDATE 2
    So is putting the larger and larger idle jets in lowering your idle speed? It sounds like you are increasing the amount of fuel going in to compensate for an air leak.
    So for the love me I could not find an air leak. Got it running perfectly on the 60 jet 2 turns out and went for a quick brap. Bike ran unbelievably great. Then all of a sudden I had a hanging idle again, then it went away then right when I got home it was hanging again. So I pulled out my can of carb cleaner and went all over the insulator boot and found a very tiny air leak. Only was able to find it after drenching the boot in cleaner. Took the boot off and found where a lip had a tear on it right were I was able to get the rpm to jump with carb cleaner sprayed on that exact spot.

    Just ordered a new insulator boot from my local Honda dealer. Picking it up tomorrow. Hopefully this was the original issue and Reinstall a 45 jet and see what happens. Hopefully that's perfect. As that's what I would expect it to be.
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    by Aussiecrf230 » Wed Nov 30, 2016 2:14 am

    At least after replacing the boot you will have a selection of idle jets to pick from so you will get it spot on.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • Leardriver
    Posts: 462
    Joined: Wed May 05, 2010 10:33 am

    by Leardriver » Wed Nov 30, 2016 2:20 am

    Return to a 45 pilot at 2 turns out on the fuel screw. None of these bikes need big jetting variances to run right.
  • Bill93
    Posts: 22
    Joined: Tue Jul 21, 2015 11:02 am

    by Bill93 » Wed Nov 30, 2016 11:23 am

    At least after replacing the boot you will have a selection of idle jets to pick from so you will get it spot on.
    I have every jet size from 38 to 62 now. Not the end of the world since this jet is the same as a few other bikes of mine. One of which will need a bigger jet when it gets the new pipe and other things I've been meaning to put on it.

    @Leadriver what I am expecting. Also the reason I posted as the Jetting was baffling me. I've rebuilt a few carbs and have never had so many issues. Amazing such a tiny tiny air leak threw it off so far.


    EDIT:
    Part is ordered. I'll deff report with updates when it comes in Monday.

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