If you parked your motorcycle and let it sit for the winter, you may need to have the carb(s) cleaned before your bike will start back up again. Keep reading to find out how to diagnose this issue for yourself, and what you can do to prevent it from happening again.
I offer diagnostic, repair, maintenance, and modification services for motorcycle riders and enthusiasts in the Denver metro area.
To schedule an appointment, call (719) 565-9295.
I am *MOBILE*, which means I come to you and fix your bike on-the-spot in most cases.
NOW OFFERING: Ultrasonic cleaning for carburetors and other small parts. I will take your carburetor(s) with me and clean it in my ultrasonic cleaner, if necessary.
How to diagnose a motorcycle that needs its carburetor(s) cleaned
Start by seeing if the bike will run with the choke activated.
If it starts on the choke, let it warm up. Shut the choke off after 5-10 minutes of run time.
Does the bike die? If it starts on the choke but stalls when you shut the choke off, the carburetor(s) need to be cleaned.
The ethanol in today’s “high tech” gasoline turns into a gelatinous mess when it sits for a period of time. The gelatinous mess then plugs up your pilot jets, thus preventing the bike from continuing to run when you shut the choke off.
“My bike won’t start at all, does it need its carb(s) cleaned or is it something else?”
Head down to your local auto parts store and buy a can of carburetor cleaner.
Now find your bike’s airbox. You may need to remove the seat or the fuel tank to find your airbox.
Squirt some carburetor cleaner into your airbox. Don’t worry about removing your air filter. Carburetor cleaner dries pretty fast. It shouldn’t take much.
Now activate your choke and try to start the bike. If it starts at all, even for a few seconds, this is a good sign that your carburetor(s) need to be cleaned.
If it won’t start, spray some more carb cleaner into the airbox and try to start it with the choke off. If it starts at all, even for a few seconds, this is a good sign your carburetor(s) need to be cleaned.
If your bike won’t run at all on carburetor cleaner, i.e. alcohol, then there’s probably something else wrong with your bike. It may have a spark and/or compression issue, in addition to fuel delivery issues.
Why does my bike run on carburetor cleaner but not on gasoline?
Internal combustion engines designed to run on gasoline require a specific air/fuel ratio to run. This ratio is called the “stoichiometric ratio.” For gasoline, it needs to be right around 14.7:1 for your engine to run.
The stoichiometric ratio for alcohol is way, way wider. I don’t know the exact numbers, but experience has shown me that if there is any alcohol at all in the system your engine will run, assuming there isn’t a spark or compression issue. If the bike won’t run on alcohol, there’s a good chance you have a spark or compression issue.
Fuel, Spark, Compression: Internal Combustion’s “Holy Trinity”
For your bike to run, you need fuel, spark, and compression. Using alcohol to see if your bike runs allows you to verify that your bike has spark and enough compression to run.
If your bike runs on alcohol but not on gas, your bike has a fuel delivery issue that can probably be solved by cleaning the carburetor(s).
To prevent this issue, all you need to do is drain your carburetors before you store your bike. I can show you how to do this during your appointment, or I can do it for you as winter approaches later on this year, when you’re ready to store your bike.
How to schedule an appointment
Call (719) 565-9295 to schedule an appointment. Appointments are available 7 days a week, sunrise to sunset.
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