Harley Carburetor Troubleshooting
Bob LaRosa
Video Player is loading.
Description
Bob’s at the bench with your Harley carburetor troubleshooting questions. He gives his suggestions on where to start when you are having fuel delivery issues. He also gets into other issues that might be the issue for a “stumbling” motorcycle.
Watch how to rebuild your carburetor with our Carburetor Rebuild Class.
Hi, I'm Bob LaRosa. Welcome to "Fix My Hog." I get a lot of questions when it comes pertaining to carburetor running issues. The most typical question I get is, "I'm driving along at 60 or 70 miles an hour, "and my motorcycle wants to stumble, fall flat." You need to do a lot of research. You need to bring a lot of answers to the table before you can start doing any type of troubleshooting. What I always recommend, take a piece of masking tape, put it on your switch housing, put a piece of masking tape on your throttle, and make yourself some hash marks on the switch housing, a stationary point, and on the throttle, in let's say, 1/8 increments.
And when you're riding, see where that throttle is in relation to wide open. You'll find doing 60 miles an hour that throttle's barely open. You may still be running on the slow jet solely. A lot of people will get a stumble 60, 70 miles an hour. First thing they want to do is either up or down the main jet size.
That is you're not even on the main jet circuit, unless that throttle is open accordingly to utilize the main jet circuit. A lot of carburetor issues that I encounter are fuel-related. Float bowl not correctly set, the needle not seated into the needle seat itself in the base of the carburetor, whether it's swollen from ethanol that's found in today's fuels, or it's just old and gummed up. Unless you're getting an adequate amount of fuel, you will develop a stumble somewhere throughout the fuel delivery window in the CV carburetor, or any carburetor, for that matter. Six out of 10 issues I come across when people are hellbent on telling me that the carburetor's not functioning correctly, has nothing to do with fuel, fuel delivery, jetting, or proper carburetor operation.
A lot of problems come from half-fouled or dirty plugs, failing plug wires, failing coils, sensors that aren't working correctly, additional electrical add-ons that are drawing too much voltage from the ignition system. Again, you just can't say, "My bike at 60 miles an hour, it stumbles. "I need a bigger main jet." Bigger, when it comes to fuel delivery, is not always better. I would prefer to start with a smaller main jet, and then upgrade, up size the jet accordingly, than start with an enormous main jet that's just flooding everything. Not only does the motorcycle run rich, smells like gasoline when you're riding, but you run the risk of washing the oil layer on the cylinder away from the rings and the piston, and causing internal engine damage from too much fuel.
Again, carburetion is very simple. When it works correctly, it works correctly. When it's not working correctly, make sure that it is a carburetor or a fuel delivery issue, as opposed to a number of the other underlying issues that can arise. Electrical, mechanical, the list is endless. So, next time you may have a problem or a friend has a carburetion problem they believe is carburetor related, before you just dive in, rebuild the carburetor, or upjet or downjet unnecessarily, take a little time, refer to your service manual.
Refer to other people who drive the typical bike like yours, and do a little diagnostic before you just dive in and blame carburetion for any poor running problems.
I have 2001 electric glide that CV carb. Will not idle unless choke is on, I've have replace all the jet clean carb with carb cleaner. What else may be causing the problem.
My Harley starts but won't stay running,any suggestions?
Hello, I have a 1990 Harley Electra Glide with only 9000 miles. Bike sat in garage for 1 season without being started. I fired bike up last week started riding after about 4 miles gas started leaking out of carb overflow tube. I nursed bike home removed bowl on carb noticed some sediment. I cleaned all jets and bowl and installed new float seal, started bike same leak, any ideas? Also any way to properly adjust float height without removing Carberator? Thank You very much! Mike.😎
I just cleaned my carburetor on my 2004 sportser 1200,and now the bike will only run when its choked.
i have a 1993 flstc. out of no where , the carb started leaking from the float bowl. it looks like it might be coming from around the shaft that operates the diaphram on the side of the bowl. what should i do?
My bike will only idle when the choke is on. May have old gas.
Your Harley carburetor troubleshooting is not working...there is statement in the video window that the video is currently experiencing problems, check back soon. I was really looking forward to seeing this video as my 883 won't start. Can you tell me te best chemical solution for soaking carburetors to clean out gunk without having to disassemble the carb. Cheers, Pete
More Carb Q&A Here: http://www.fixmyhog.com/post/tag/carburetor/
Q: 2003 Sportster 1200, I am having problems with my carb. I put an RV cam in it, and Ultima programmable ignition system. The carb is a Ultima R-2, it has a 062 main jet as it is now I get 53miles to a 3-1/2 gal tank. I would like to know how low I can go on the main jet without starving the motor, and gain fuel mileage. Thank you Any advice will help Bill B A: You need try to go down on the intermediate (slow) jet. That is where most of your riding is done. Try dropping one size and see how it goes. If your spark plugs begin to look white, you are too lean. If you try dropping down more than 1 size, you should also, then, drop your main jet. If the Jets are too far apart (in size) you will not have a Smooth transition between jets when you really open up your throttle.