20 hp honda 10000 kva porter cable, make electricty put will not speed up under a load stays at idle.give it gas at the carb. by hand and it will run a power tool ect. Thanks

Fuel starved, carb should have an idle adjustment which sounds like it is fine. Look for the second adjustment

Hey Fred, I AM SOOOOO JEALOUS!!! My teenage years Saturday nights were spent in a 64 Fairlane...(4 speed - 390 - WOW!!)..
Any way.. your carb needs some TLC, a valve clearance setting-get a qualified pro to do this!!), new spark plugs (wires maybe) .. a new air filter.... mainly the carb needs a QUALIFIED PROFESSIONAL to clean and set it once you have put in the plugs/air filter.. This will eliminate possible rough idle issues and give the mechanic peace of mind when he is adjusting the carb.
Good luck...

you may have a vaccume leak try spraying some carb cleaner around the carbs and intake ports while running and see if that changes the idle speed or allows it to idle for a second, otherwise it still sounds like a carb problem please rate

First, as you look at the motor you will see cables attached to the carb. When you have the motor off move the throttle cables forward and see which cable moves the carb part. The other cable moves the outdrive gears and thats not what you want.

When you find the correct cable unhook it from the carb. Now the carb is free to move by hand. When you pull back on the carb "arm" you will find it is spring loaded. The carb arm will return to where it is set. BUT it must be done after the engine is warmed up or you will be fighting the choke.

As you let the arm return several times you will see a screw that part of the arm always hits when it stops.
Do this until you see this contact. It is this screw which is turned to make the arm stay open wider.
This will increase the RPM.

You do not want the engine to run very fast at idle. It causes the outdrive to BANG into gear and will cause problems with docking and NO WAKE zones. You may increase it to 600-625 RPM. There are also different effects with different props concerning idle speed.

Finally, after you set the carb where you want, you need to adjust the cable you removed earlier so it is pressing the carb arm slightly and helping the return spring close the throttle.

Another reason for lower RPM at idle is that under the right circumstances the fuel can bleed into the engine because the throttle is cracked open too far. This can cause a wash down of the cylinders and you end up with gas in the oil.

Preset both needles about 1-1/2 to 2 turns CCW from CW stop. Set H needle first after warm-up. At high speed, engine should 4-stroke with no load, but smooth out with light load(cutting wood). Set idle speed so that it will keep running, then adjust L needle so that engine tries to follow the throttle, but idles fairly smoothly. Readjust idle speed so that the clutch is not trying to drive the chain.

Your carb may be the issue but your ignition coil could be the culprit. Once they start going bad, they can act up intermittently or give various symptoms from day to day. The fact that your saw dies at full load or under load, probably means that when your saw gets hot or requires more spark, your coil is not able to provide it. Your carb is easy enough to clean out, you can take it all apart and clean all screens, etc....

I just replaced my coil due to the exact same symptoms and now my saw runs great. $60 off ebay and you can put it on in 15 minutes yourself. Check your carb first though

Turn off the gas and remove the water trap bowl at the bottom of the petcock, (gas valve). Dump it, clean it and re-mount it, ( not all bikes have a water trap bowl ). Get a set of the stock NGK spark plugs your bike came with. Check for spark on each cylinder before installing the plugs.

Now go to the idle and air screws on the outside of each of the carbs. IMPORTANT > > GENTLY turn both screws all the way in until they LIGHTLY seat. Now turn the screws EXACTLY one and one half turns outward.

SYNCHRONIZE THE CARBS
Remove the air filter and rubber fittings to allow you to see into the throat of both carbs. You may need a mirror to see inside. You need to be able to see the slides go up and down when you twist the throttle. Now turn the fitting where the cable goes into each carb such that there is just a bit of slack in the cable, 1/16" is plenty. Lock ONE of the cable adjusters down tight. All further adjustments will be made on the other carb.

With the motor turned off twist the throttle very slowly while looking at the slides. Both slides need to begin lifting at the exact same moment. If the slides don't raise at the exact same time then slowly twist the throttle until the locked adjuster slide just barely starts to move. Hold the throttle still and turn the adjuster on the other carb so that the slide on that carb just barely starts to move also. Now recheck the slide movement timing. Do this process until the slides on both carbs begin to raise at the EXACT same moment. Lock down the loose adjuster and re-check the slides.

BALANCE THE CARBS
Turn the throttle screw on the LEFT carb one half turn inward. Now start the engine and get it warmed up. With the engine running, remove the RIGHT spark plug wire. Adjust the idle speed on the left carb to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

Now turn the throttle screw on the RIGHT carb one half turn inward. Restart and rev the engine. Next, remove the LEFT spark plug wire. Adjust the idle speed on the right carb to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

Turn the idle screw on each carb EXACTLY ONE QUARTER turn outward and restart the engine. The engine will be probably be idling very fast. Adjust both the idle screws equally from this point to get to the desired idle speed. Congratulations, you have just synchronized and balanced your carbs.

PLEASE RATE THIS SOLUTION. Thanks!

Hi, You did a good job of diagnosing your problem. Gas in bowl and dry plugs, starts with fluid, But, to quote you, "won't go through carb" . If you feel confident, you should disassemble and clean the carb, as that is going to be the problem. As a tip, if the genset is going to sit make sure to turn off the fuel flow to the engine and run till the engine dies. They do not like to sit any length of time with fuel in the carb. Good Luck, this should Fixya!

You have a simple problem and it has nothing to do with the octane, honda's love better gas, thats all I use in all my equipment and even my 4000 psi pressure washer runs better and cooler with higher more efficient octane, Your problem is in the carb, clean and service it, make sure the air breather is clean (soap and water only if it is a foam unit and do not spray it with any oil) then check for water in the gas by draining the tank into a large clear glass container 1/2 gal at a time. and after all this is done and needs to be done anyway, change the spark plug run the unit and make sure the throttle up solenoid is adjusted properly or even working if this unit is equipped with one. good luck

Have you tryed ajusting your carb choke?