Pilot Jet Cleaning

[Deleted]

The best way I have found to clean stock pilot jet is with a wire. Chemical cleaning and compressed air sometimes leaves the jet partially clogged.

The wire can be made from a "bread tie" wire and sanded to be between 0.011" and 0.0115" in diameter. I did this, then wrapped one end of the wire around a small pocket screwdriver handle to form a loop. Then wrapped the wire around itself a few times to tie it off. This gave me a small loop to hold while using the wire to clean.

If the wire becomes bent, simply grabbing it between your thumb and fore finger and pulling it through will straighten it out.

Several gentle pushes back and forth through the jet cleans it completely.

[jdl357]

I've heard that very fine guitar wire also works well and doesn't bend.

[190mech]

Fine wire brush bristles too..Just remember,all the manuals say to NEVER use a wire to clean jets,so none of us folks at 49ccScoot will EVER follow this thread!

[Deleted]

190Mech, you probably know some of this, but it is here for those that don't know.

What you are suggesting has some validity when applied to the "E" type carburetor. The reasoning is emissions control as is stated in section 6C of GM service manuals. As any minor jet size increase would cause a rise in emissions.

However, it does not apply to carbs that are strictly mechanical in nature and never did. In fact during their production, the four main USA carb manufacturers (Rochester, Motorcraft, Holly & Carter) openly stated in product training classes their preferred method of cleaning partially clogged jets was a "Burroughs Carb Clean and Adjust Kit". In fact they promoted this heavily. Even the European manufacturers SU and Stromberg recommended the Burroughs kit as well.

Here is why, during the day of vehicles with carbs the mechanic had a cold immersion "carb cleaner" that was somewhat acidic and did an excellent job of cleaning most carbs. It did not attach the coating in the carb float bowl. Unfortunately that cleaner has all but disappeared from the trade, I suspect MSDS & product liabilities plays a large part in that.

Also during that time, alcohol was not present in the fuel and therefor the carb was not attacked (aluminum corrosion) by the fuel. This aluminum corrosion deposits everywhere, but more so in the idle / pilot jet of these little carbs.

I strongly remember the Rochester Monojet, had one jet somewhat hidden in the carb float bowl and ANY restriction in that jet caused all types of performance problems.That carb was found mostly on the 200CI and 250CI inline 6 cylinder engines.

I am not suggesting that my way is the only way, I am only offering it as help to those that want to get their scooter running right when typical cleaners don't work. It is a far quicker way than waiting 2 or 3 days for a replacement jet. And IF they are going to replace the jet anyway, why not try to clean it this way? It might work for them as well and get them back on the road.

The size I suggest does not open the GY6 50cc idle / pilot jet up any beyond original as I have checked exhaust gasses and there is no emissions increase when done as I suggest.

btw... Out of curiosity, I checked several (4) scooter maintenance manuals plus a motorcycle carb only manual and none of them stated any preference on how to clean the carb or the jets. And you are welcome to replace these jets instead of cleaning them. Afterall, it is your call.