20 Most Recent 2003 Honda CRF 150 F Questions & Answers

needle not attached to float properly or a hair or the like not allowing the needle to close off properly

120-135 psi

Remove the side cover on the opposite side of the shift lever. Once opened you will see the gear shifter there is a spring on the shaft look if it is in its correct place or if it is not broken

Sounds like selector bent or broken .

hold the carb upside down and just as the float rests on the tip of the float needle that is spring loaded the floats should be flat across ie 90 deg !!

change the jetting...youcan contact FMF for thier setup recommendations for running that pipe with the bike...very common problem and jetting will take care of alot of the issue

ALWAYS have a fire extinguisher on hand when working on carburetors.
Remove the water trap bowl at the bottom of the petcock, (gas valve). Is there any water or trash in the bowl? Drain a cup of gas from the tank. Is there any water or trash in the cup? Dump it, clean it and re-mount it, ( not all bikes have a water trap bowl ). Flush out the gas tank if needed.

Drain the carburetor. There should be a screw on the lower side or bottom 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 into all the little airways and fittings in the carb. Remove the idle screw and the air screw on the outside throat of the carb and spray into the screw holes as well.
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Be sure to put these two screws back in the same hole they came out of. IMPORTANT > do not tighten these two adjusters down. Only screw these in until they LIGHTLY seat. Now turn each adjuster 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. Post a comment to get back to me.

A “very helpful” rating on this answer? Thanks!

Ok most likely cause for this is jetting (Carbi) and or the air / fuel mix screw set to rich - Well done for noticing though as no where near enough people read their spark plugs and make adjustments - they normally wait til bike don't work before researching?
Simplest and first option would be turn in your air/fuel mix screw quarter to half a turn in (clock wise) this leans the fuel mix slightly
Second option if still not helping from just screw adjustment is put the mix screw back to where it was before and change the pilot jet to a smaller size - the pilot jets have number stamped on them so once you have yours out look for the number and just buy new 1 or 2 sizes smaller (they only about $5 each) then of course go back to fine adjustments on your air/fuel mix screw to find the correct balance
You will very quickly know if your setting is to lean as result of adjustments as you will get back firing when rolling of the throttle if becomes to lean
jetting and air fuel mix adjustments can be annoying sometimes as you may need to go up a bit then down a bit then up again but take your time do very minor adjustments then check results and my tip is only ever change one thing at a time then record the change then test and record the result if you dont you will very quickly forget what you did, not know what to reverse if result was poor and if result was good you won't know exactly what made the improvement.
good luck mate regards Jamie

Change oil/filter regularly, check valve clearances regularly, compress air clean carbi and all jets regularly, clean or replace air filter regularly
thats it!

you need to use multi meter to test resistance readings from the stator your owner manual or bike shop can tell you what readings are within spec for each source on the stator but from what your saying and the age of bike almost definitely would be stator related
stator would normally have 2 or 3 sources of power or alternatively called tappings of the one stator my guess is when you test it with meter (OHMS) readings you will find at least one of the source power being out of spec and pretty much if any of the tappings or sources are out of spec you will not get bike to start from kick over - you will have weak spark or no spark!
any bike shop should be able to test the resistances for you if you dont have multi meter

good luck regards Jamie

First be sure the cable is seated into the top cap of the carb. Check the clip on the needle. It should be in the center groove. Check the slide to be sure the notch in the side of the slide is lined up with the pin in the inner side wall of the carb throat and that the slide moves freely when the twist grip is operated. Is the throttle cable kinked or pinched abraded or routed improperly? Is the seal on the manifold still good? Is the manifold tight to the head and carb? Please rate my answer. Thanks.

Kickstart spring not reinstalled correctly and/or ratchet guid plate not reinstalled correctly,have to disassemble and try again.

sounds to me like u r reeving engine too high (running it to hard in low gear)

its take time to to change the tube if your have u dont got a tire changer (if you are only usein hand tools try not to wreck your rim or tube when relplaceing a new one.

What I have done is to spay WD-40 between the throttle gas, feed several drops of 10W30 engine oil to lubricate the throttle cables and ensuring that the throttle is fairly lubricated around the carburator's throttle neck. Please give comment and rating if advise useful. Thanks

93 super is the best of street pump fuel to run in it.

it is located on the back of the cylinder on the left side of the bike. It will have 3 8mm bolts in it and it is spring loaded. reinstalling it is a bit tricky you will need a very small straight screw driver to insert in the middle of the tensioner to load the spring and put it in loaded. I hope this helps you

If the chain is loose then you need to replace the chain the adjuster is automatic so you cant adj the tension but you do need to ck the guide some times the guide is worn where the adjuster pushes on the guide so if the guide is good then replace the chain but look close at the guide first that will wear out before the chain will strech most of the time let me know what happens thanks Don 678 768 2732