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The engine starts and idles with the choke on, but when cold stops as soon as the choke is off it also cannot get high rpm needed to operate the saw I cleaned the carburetor, replaced air filter, but o results
Most likely that the cylinder bore is worn or scoured. If so the cylinder & piston will need to be replaced May not be economically worthwhile Most likely that the cylinder bore is worn or scoured.
If so the cylinder & piston will need to be replaced
May not be economically worthwhile
Remove clean and reinstall the spark arrestor (muffler, if it cannot exhale it cannot inhale). Have you inspected the fuel lines? If it only runs on choke it is lean. I think broken fuel line or maybe an air leak at intake boot connection. If all good reply below and we will continue. If you need to replace fuel lines post that back and I can help there too, I am a helpful guy. HTH LouRemove clean and reinstall the spark arrestor (muffler, if it cannot exhale it cannot inhale). Have you inspected the fuel lines? If it only runs on choke it is lean. I think broken fuel line or maybe an air leak at intake boot connection. If all good reply below and we will continue. If you need to replace fuel lines post that back and I can help there too, I am a helpful guy. HTH Lou
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no year told, nor when it last run perfect not told
same answer for 100 years on any otto cycle gas engine made car or motorcycle or scooter.
same., and drives fast too, full power work but idle fails.
well , idle is too rich, as are all carbs this old and never serviced.
when it stalls i bet spark tip is wet with fuel or carbon fouled.
or bad fuel. or caused by bad fuel endless for 100years
ive cleaned like 1000s of carbs in 50+ years. endless. me.
it's only a 150cc engine, and tiny carb. my CB750s old and new.
both had 4 carbs and are tricky and must be synchronized
but your's is a pussyycatt. 1 carb small
causes all.
the float needle is bad causing too high float level.
the jets are bad or wrong or dirty. there may be 2 jets one is idle and bad. but most time not 2, just 1 jet and 1 needle.
the needle can be bad , most are this old and bottom of needle is idle section OF NEEDLE and all worn out and now super rich at idLE SPEED
the air paths inside the body of carb must not be clogged
all tiny air paths. checked and cleaned fully.
that is all I can think off off hand.
my guess is bike is super old.
is bike real honda or this trashy china clones of 80 honda.
no year told nor photo of it so we can ahhhh that BIKE,
THE TANK VIEW IS OMG EASY TO ID.
NOT TOLD , FAILS IDLE HOT AND COLD ENGINE BOTH.
Using throttle grip hold RPM up a tad to get it hot first and see if idle reall fails hot.
first 150cc bike owned ever,?yes
the learn this.
we start with mild choke cold and back it off bit by bit until warm.
the chock has a fast idle features that must not be broken.
back it off slowly for 5 mins. then idle works
some have idle mixture screw on the side or is fast cold idle screw.
the cables are not for idle. ever and are set loose side
a stop screw idle and maybe mixtures idle. tool
depends on year not told if honda mikuni made.
My Harley is very slow to warm up, it also does not like to idle without choke unless it is good and warm. It could be the clogged filter was acting like a choke, but ruining your gas mileage. Now with air flowing smoothly the engine needs a bit of choke to idle. It should not need choke once it is fully warmed up unless your idle speed is set too low. With the engine hot, check RPM if you have a tach. If too low, adjust the idle speed at the carburetor. I suggest you find the adjustment while the engine is cold.
That would be your engine "choke" functioning. It's not a problem. The choke engages when engine is cold and shoots extra fuel to the cylinders to idle the engine up especially in cold with. Once the engine has sufficiently warmed up, the engine will idle back down.
No to both questions. The idle valve is only for idle control, letting in more or less air as idle conditions warrant, to keep engine at proper idle RPM. The old choke would reduce air supply on a cold engine to allow starting with a richer gas mixture. That function is taken over by the computer in injected cars by allowing longer injector pulses to give richer mixtures in cold engines. Once warm, the 02 sensor controls fuel trim through the computer. By "accelerating itself", do you mean your idle is higher now that it's colder outside? I suppose it's possible if the idle valve is out of calibration, it might cause that. It is computer controlled, so proper diagnosis of the idle control valve requires a multimeter. The throttle position sensor should also be looked at for a high idle. Good luck.
If the carb is adjusted correctly, the engine will not idle without the choke when cold. I will usually take at least 3 to 5 miles of riding to get the engine warm enough to idle by itself without the choke. If your bike is a full operating temperature, it should idle at about 1000 RPM. If it's idling higher than this, you need to slow it down a bit.
Remove the air filter cover and look at the top right side of the carb. You'll see a screw there . This is the throttle stop screw. Turn the screw counterclockwise to lower the idle speed to 1000 RPM or so. Blip the throttle and let it settle back to idle. Reset it if necessary. Once set, put the air cleaner cover hand on.
There appears to be a thermal movement of choke mechanism that comes about once vehicle is warmed up. Check the chock connections, hot water pipe and linkages tight or clear.
gazakat
Hi This sounds like a cold start system fault, which is a number of things.
Cold start temperature sensor not operating correctly so the cold start system won't work when the engine is cold.
The idle needs to be set to the correct RPM of the engine when warm, if it is idling ok when it is warm then this wont be the problem.
Spark Plugs are worn and need replacing.
Most case's its the cold start system not operating correctly and if you have a good workshop to take it too they should pick this up quite quickly. Hope this helps, let me know how you get on.
ok buddy on the carb will be some sort of screw and idle screw turn this in 1/4 of a turn with the machine running until it idles at 1000rpm also the choke will stall the engine when warm the choke is only for cold starts get back to me more info or problems
Like to other guy said, give it a tuneup. Also try SEAFOAM to clean carb up of slug. Also check to make sure the butter fly for the choke has not come loose, causing it the choke it down. Failed choke pull-off.
Most likely that the cylinder bore is worn or scoured.
If so the cylinder & piston will need to be replaced
May not be economically worthwhile
Remove clean and reinstall the spark arrestor (muffler, if it cannot exhale it cannot inhale). Have you inspected the fuel lines? If it only runs on choke it is lean. I think broken fuel line or maybe an air leak at intake boot connection. If all good reply below and we will continue. If you need to replace fuel lines post that back and I can help there too, I am a helpful guy. HTH Lou
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