How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ranwell1 Your Own Question
Ranwell1, Small Engine Technician
Category: Small Engine
Satisfied Customers: 10304
Experience:  I Own a Lawn Mower Sales and service business (37years). Have 2-cycle and 4-cycle certification.
Type Your Small Engine Question Here...
Ranwell1 is online now
A new question is answered every 9 seconds

I have troy bilt TB90BC weed eater 2-cycle. It will not start.

Resolved Question:

I have troy bilt TB90BC weed eater 2-cycle. It will not start. Looking for way to adjust carb.
Submitted: 6 years ago.
Category: Small Engine
Expert:  Ranwell1 replied 6 years ago.

In most cases these carburetor are of the non-adjustable type. Even if you have an adjustable carburetor, it most likely would not correct the problem. Most of the time (almost 95%) the problem is a dirty or restricted carburetor coupled with stiff or worn diaphrams. This is usually caused by leaving fuel in the unit over the winter. Gas cannot be left in a unit or on a gas can for more than 30 day without causing problems.



As engines sit or get older, fuel that is left in the carburetor can turn to gum and varnish and cause this and other problems. Also, any gasoline that was left in a gas can for a period of more than 30 days must be discarded because it also has begun to turn to varnish.

Today's gasoline's contain MTBE and alcohol. (Ethanol) They turn to "Junk and garbage" very quickly. Alcohol is partially water (H2O). And they call it "Oxygenated fuels! It is the oxygen that breaks down the organic compounds in the fuel and turns the gas to "Garbage" (Gum and varnish) The fuels we had just a few years ago had no alcohol in it and would store for longer periods of time before going stale... and fuel stabilizers do almost nothing to prevent the fuel from going bad with the changes in today's fuels.

Do not buy gas from the "Discount" Stations. The discount stations get a reduced price on gas because they may be buying fuel that is nearly 30 days old already. You may be getting fuel that's nearly stale right from the pump when buying from a discount station. Purchase your fuel from the well-known stations such as Shell, BP, Sonoco, Phillips 66 etc.

More than 70% of all of our repairs in our lawn mower business are due to this same issue. You most likely have dirt, gum, varnish...etc in your carburetor plugging up the small passageways and jets in the carburetor.

The carburetor must be removed from the engine. Clean all parts with carburetor cleaner and blow out all the small holes and passageways with compressed air. Remove all of the non-metallic parts since the carburetor cleaner will cause them to be disfigured decompose and plug the carburetor as time goes on.

Wash the carburetor cleaner off of the metal parts by washing them in warm, soapy water then rinsing with clean water. Dry them by blowing it off with compressed air. Make sure that all the passageways are blown dry before reassembling.

Reassemble using a NEW carburetor rebuild kit.

DO NOT TRY TO REASSEMBLE WITHOUT USING A COMPLTE CARBURETOR KIT! You will just end up having to do the job again.

ALWAYS clean the fuel tank and replace the fuel line when doing this repair or you may have to do it all over again. The inside of the fuel line disintegrates over time and these small pieces of rubber will plug up the carburetor too. Dirt and water from a dirty fuel tank will also plug up the carburetor. Find the Model, type and serial or code numbers off of the engine and take them to your local dealer to get the carburetor repair kit.

If you do the work yourself, take pictures or at least make a drawing of where all the linkages, gaskets, and component parts go. Correct reassembly is critical.

If the carburetor still doesn't work correctly, you may have to take it to someone who has an "Ultra-sonic" cleaning machine. This machine uses carb cleaner and ultrasonic vibrations to get the very small passageways clean when traditional methods fail.

If you don't feel comfortable with this kind of repair I would suggest sending it to a reputable shop.

Feel free to contact me here at this question anytime ...even after you hit the "ACCEPT" button ...and I will try to help further.


Please click "ACCEPT" or I won't get paid.

You may also consider sending a bonus if I have been helpful, Please leave positive feedback this is how I'm rated. Thank

Ranwell1 and other Small Engine Specialists are ready to help you

Related Small Engine Questions