After winter storage I tried to start the bike but found it was not idling on one cylinder. I splash a bit of water on the pipe to see which one is not firing. After removing the float bowl from the 3rd carb from the left as you are sitting on the bike, I checked for dirt at the bottom of the bowl but found none. I removed the idle mixture screw and spring and got a small piece of fuel line and shoved it up inside the opening. I gave the tube a few shots of carb cleaner to dampen up the jet with cleaner and left it to soak for 30 minutes. I did not remove any of the other jets as I had cleaned them all out the years prior. After reassembly, I tried the bike and it did correct the issue and it idled fine. I was considering cleaning out the other three idle circuits when I came to realization that you don't have to remove the float bowls to cleanout the idle circuit. The idle screw is not inside the float bowl. This is quite often the cause of these bikes not running well, because the idle circuit has become partially or completely blocked due to storage or debris entering the gas tank. These bikes do not like dirt in the fuel. Just thought I would point out that a lot of the poor running issues can be sorted out by simply cleaning out the idle circuit without the need for removing the carburetors or even the float bowls.
Cleaning carburetors
- Thread starter Stan C
- Start date
If I have carbs that I know were working well and then suddenly aren't working well I use a high dosage of Seafoam, saved me many carb disassembly's over the years. I'm always shocked at how many people don't use fuel filters.
Fuel filter or no fuel filter, if you let the bike sit for some length of time without running it dry or draining the float bowls can result in the idle or low speed circuits getting gummed up with deposits. I did not do this last winter and I had an issue with one cylinder not firing. Always at least run it dry before storing. I had the pleasure of unplugging the #2 jet again on Saturday August 21 through the 23rd (2025) This time it seems the low speed jet was partly or completely blocked. I followed a maintenance procedure that I found on here and followed from page 13 on and it seems that the low speed circuit is vulnerable to jet plug. I did 3 carbs but skipped over the hardest one number 2 from the left side sitting on the bike the one with the accelerator pump. I did this because I had all the carbs apart from the bike last year and this year the bike started and ran fine. The second time I started it it obviously had some dirt go through or get deposited from leaving the bowls full over winter. I used an E string as suggested but an E string is around 0.010 and the low speed jet is 0.0159 or something so if you can find a string with a o.014 inch diameter would be the best size. I tried to use a 0.016 sring but it would not pass through the orifice. After assembling everything back (keep in mind that I DID NOT REMOVE THE CARBS FROM THE BIKE) This is the fourth time cleaning out the carbs, the third time with the carbs on the bike. The only time I removed them from the bike was unsueessful in solving the rough running issue but when I think back, it was probably due to lack of knowledge through research over the three years of ownership. I did own a 1980 F model but sold it many years ago in the 90s after owning it for about 5 years. It started to run a bit rough but I never cleaned the carbs out. A very nice bike in silver with red stripes and 4 into 2 exhaust, dual front brakes and disc on the rear as well. I paid $3006 for it in 1981.
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