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When to adjust idle

I realize this should probably be done when warm, but should it be done before starting or while running (if i can keep the bike from stalling)?

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If you can keep the bike running long enough to get it warm with and with no choke then that is when you should adjust the mixture,
First though start by adjusting it cold so the screw is set at about 1.5-2 turns out then run till warm set idle at around 1500 revs and adjust until it just starts to lift the revs then back off a quarter turn

Posted on May 03, 2013


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Posted on Jan 02, 2017



  • 126 Answers

SOURCE: wont run /idle

i'd start with removing the carbs and giving them a thorough cleaning as when bikes sit for so long, the carbs begin to get gummy/varnished from the old gas.

check for blocked holes in the pilot jet & main jet and look for "hard & dried up" gas in passages. be careful of the float bowl gasket as to not tear it or you will need a replacement.

Posted on Mar 06, 2009


  • 3567 Answers

SOURCE: Idle adjustment

If there is not a screw on the side of the carb then look at the top of the carb where the throttle cable connects. The fitting at the top of the carb is threaded and would adjust the carb idle. There may be a similer adjustment at the twist grip but I don't remember one there.

Hope you can rate this solution as a 'FixYa'

Posted on Mar 21, 2009


  • 3567 Answers

SOURCE: Tuning problems with 1985 Honda CR125

Remove the water trap bowl at the bottom of the petcock, (gas valve). Any water or trash in the bowl? Drain a cup of gas from the tank. Any water or trash in the cup? Dump it, clean it and re-mount it, ( not all bikes have a water trap bowl ).

Drain the carburetor. There should be a screw on the lower side of the carb float bowl. Remove the screw then replace it after the fuel drains. Turn the gas back on and wait a minute for the carb to fill with gas. Install a new stock NGK spark plug and try to start the engine. If the bike doesn't start and run properly then shut off the gas and remove the carburetor from the engine.

Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray all the little airways and fittings in the carb. Remove the two screws on the outside throat of the carb and spray into the screw holes as well.
Be sure to put these two screws back in the same hole they came out of. IMPORTANT > do not tighten these two screws down. Only screw these in until they LIGHTLY seat. Now turn each screw one and one half turns outward. Put the rest of the carb back together, clean the air filter and install the carb. Let the float bowl fill then start the engine. This process should get you back on the road.

Please rate this solution. Thanks!

Posted on Mar 29, 2009


  • 3 Answers

SOURCE: stalls once warmed up

I have the same bike, Ca. model. Idon't know how much work you have put into the carbs, but you may have more than one problem. You can pull the pet ****, disassemble it and check to be sure the diaphragm is not sticking (i.e. due to moisture getting into it and setting and not running it enough to fully dry out everything, ) you can be a little rough with it, cause if it fails, it needed to be replaced, It works off a vacuum tube off cyl 2 and once vacuum is established, it opens the valve-- hence you don't have to turn the valve to "off" to prevent fuel from seeping into the carbs n flooding them while it sits .Pull the diaphragm n stretch it a little with the sun or bright light behind it to check for tiny pin holes. One tiny pin hole will mess with things in funny ways. Replace ir they're cheap.The whole pet **** as a unit--- cheap enough anyway. Then as with most small displacement older bikes the carbs have to be treated like royalty. Pull em and cleanem. Check for proper float height, this allows for proper fuel levels in the carb,small discrepancies will disturb the movement of fuel and there are four planets that have to be aligned throuhg all this to end up happy down the road. If the float pins n springs are worn replacem they do one thing only -- start the process. Then pull each jet n **** them with the exact pin drill for that jet, if a tiny bit of varnish or dirt comes out off the drill--- you just saved private Ryan. You could take the time to run the carbs (as a unit don't separate them) to a local bike place n pay to have them ultrasonically clean them along with all you do , while your in there you might as well get the rebuild kit n go for it. Then check for worn throttle valves, the pressures and speeds of fuel in its liquid state are crazy in a carb and will wear the finely measured distances between the valve and the body. Very complex and moody stuff that only gets moodier with age , like my old lady. This is all doable at home If not take the time to find the guy who works on the older Japanese bikes because they will know what you NEED to do n what you don't. Then after the carbs are back in, the synching begins. No synching no bikeing. The guy that has a manometer and an isolator rod is not the guy you should have for this. Someone with a manometer, an isolator, and an emissions machine is your guy. The fuels then are not the same as the fuels now. Remember leaded fuel? Anyway at the end of all this you will have fixed the problem, and that old bike will be a hot rod. AND it will PURR. Hold on when you hit the magic 7000. This is a major minor job that will permanently fix you to your bike.
Good luck don't forget new vacuum hoses and fuel lines and the filter n look for air leaks in the air box the old plastic warps, and new plugs........

Posted on Apr 29, 2009


  • 207 Answers

SOURCE: after warm up bike will

make sure your turning the idle adjuster to the right

Posted on Jun 23, 2009

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