Keeping your machine running
Keeping your machine running
Your powersports vehicle, whether it's a motorcycle, ATV, or snowmobile, relies on its engine to deliver performance and excitement. At the heart of many engines is the carburetor—a critical component responsible for mixing air and fuel to achieve optimal combustion. Regular carburetor maintenance is key to ensuring smooth operation and avoiding performance issues.
What does the Carburetor Do?
Rough starts, stalls, smell of gas in the exhaust? Here are some signs that your carburetor needs some attention:
- Hard Starting: The engine struggles to start, often due to an incorrect air-fuel mixture caused by a dirty or failing carburetor.
- Rough Idling or Stalling: Clogs or imbalances in the carburetor can lead to uneven idling or frequent engine stalls.
- Poor Acceleration: Sluggish throttle response may indicate the carburetor needs cleaning or adjustment.
- Increased Fuel Consumption: A malfunctioning carburetor can waste fuel, leading to higher costs.
- Black Smoke from the Exhaust: A rich air-fuel mixture caused by carburetor issues often results in dark exhaust smoke.
- Aftermarket Carb: The original OEM carburetor was removed and the aftermarket carburetor isnt performing
Case in point, we had a late 90's Polaris come to the shop for some work. The customer explained that it starts rough and always needs to leave it in gear when starting it because it idles too high. Upon further examination, we found an aftermarket carburetor that would not tune correctly, and the internals were not mixing the air and fuel correctly. After replacing it with a rebuilt OEM carburetor: She ran as good as the day she came out of the factory.
Bottom Line: If you still have the factory carburetor: Keep it and rebuild it. If you do not have the factory carburetor: Buy one
How to spot what carburetor you have
If you have a good view of your carburetor, you want to look for the names "Mikuni" or "Keihin". These were made in Japan and are the OEM carburetors for most major brands. If you have any troubles spotting it, reach out to us and let us help you. What to look for if you can see your carburetor(scroll for different examples):
For Mikuni carburetors, look for badging on the on the throttle cover
It can also be stamped into the body of the carburetor itself. This picture is from a 1997 Polaris Magnum 400
The stamping can be in different parts of the carburetor body, so you may need to look around. This picture is a carburetor from a 2001 Polaris Sportsman 500
Similarly to Mikuni carburetors, Keihin will have their badging present on the throttle cover. This picture is of a carburetor from a 2003 Honda SportTrax 400
What if I dont have an OEM carburetor?
If its running great, leave it alone. If its not and you have invested time and money into your machine, you may want to think about replacing the carburetor with the OEM.
This machine is old. Can I still find a carburetor for it?
Yes! There are a couple of options. Depending on your make and model, new OEM carburetors range from $200 to over $600. Yes. That is a lot of money. And you are probably thinking "I can just get another cheap carburetor from Amazon!" You could. If your budget is tight and dont want a brand new carburetor, another option is to get a used one from eBay. If you take this option, we recommend rebuilding it using a rebuild kit from a reputable company such as Moose or All Balls. Mikuni makes rebuild kits for their carbs as well.
The Five Mile Treatment
When a customer brings in a machine and its diagnosed as having carburetor issues, our process for OEM carburetors is simple:
- Break down the carburetor: Take it apart to the internals, removing the float bowl, needles, etc.
- Check the cables: Check the choke and throttle cables for any cracking, sticking or fraying.
- Ultrasonic cleaning: This breaks up and removes dirt, varnish, grease and even corrosion. This is a step that most shops do not do, but we do it for every rebuild.
- Rebuild it with a quality rebuild kit: We only use high quality rebuild kits.
- Reinstall and fine tune it: Make it run the way it ran when it started the first time.
This carburetor came to us from the Midwest. By the looks of it, it spent most of its life outdoors, most likely working on a farm. It was really really dirty.
After soaking in a 150 degree ultrasonic bath for 90 minutes, the dirt and grime came off. What was left is pitting from being in the weather for 20+ years. That has zero impact on the carburetor's performance
Opening up the carburetor, signs of varnish, dirty fuel and neglect were present.
As the ultrasonic waves and specially formulated carburetor cleaner worked together, the years of neglect and varnish disappeared.
Varnish is present in the float bowl.
Well it was present. The ultrasonic cleaner removed all of the varnish.
The bottom of the carburetor showed signs of tarnish from gas sitting for years and eventually turning into varnish.
You All of the varnish removed. All ports clean allowing gas to easily flow through. Its ready to be rebuilt
Closing it out
If your carb-equipped powersports machine is showing any of the symptoms above and not sure what to do, reach out to us! We are glad to talk to you about the issue and go over the options you have.
