> JBOT Admin Wrote:
> Who doesn't clean low jets lol
Obviously you are just an enthusiast. A pro doesn't waste their customers time by risking a comeback and trying to save the customer few bucks on a part that you can not guarantee is clean.
An enthusiast has time to waste with trial and error with diagnostic procedures because they are inexperienced.
Lets say Taylor came into your shop with his Honda Hobbit for: "Engine only starts and idles while the choke is on." You charge him a diagnostic fee, and quickly discover that his carburetor is varnished and needs a carb overhual to fix it. According to Taylor, the stock low jet is a #15, and (in this case) varnish has clogged the low jet.
You can soak the parts, scrape off the varnish, and use air pressure until you see light through the jet, but you can not guarantee that the low jet is 100% clean. If the main jet was not 100% clean, (with some remaining varnish), the engine will still run fine. But that is not the case with a low jet. Varnish has a thickness that will restrict a low or pilot jet.
Low jets are incremented in 0, 2.5, 5.0 (only .001"/size) or 0, 5, 10, 15 (only .002"/size). Even if varnish was only .001" thick, that is still .002" inside a hole, and that .002" is one jet size leaner than whatever size you started with. A .002" layer of varnish is a best case scenario. Mechanics or enthusiasts have not developed the ability to look through a small jet and determine if there is still a layer of varnish inside.
The most important fact is that there is no jet drill small enough to clean that low jet properly until you get a #35 low jet (it will almost work with a #80 jet drill) But the drill is actually a .34mm drill.
(Your not going to catch me trying to push a blunt or sharp wire from a wire brush to scrape out varnish from a low jet).
That is why you should replace the most popular 2 or 4 stroke low (pilot) jets from #15 to #35.
If Taylor's Honda was a 4 stroke, there are a few other details that must be attended too. You must assume there is gasoline that leaked from the carb, into the intake, past the piston rings and finally the fuel drained into the engine oil.
Diluted engine oil will quickly foul a new spark plug, and now you have related comeback after only charging the customer for a carb overhaul because you didn't see the big picture and plan ahead.
When was the last time you changed the spark plugs on your car or 4-stroke street bike?? If your car or street bike doesn't burn oil, the spark plug porcelain will be white because of the unleaded pump gas.
When I started wrenching on Kawasaki KZ street bikes, the spark plugs were always tan to chocolate brown because of the lead in the gasoline. In California we tend to do smog related changes before the other 49 states.
When companies began phasing out leaded gasoline in 1985, the spark plug color charts were rendered obsolete unless you ran leaded race gas.
Didn't you suspect something was wrong when you tried a plug chop within a short distance with new plugs? Why was there only a little color?
If you are a pro, your customers often only have a weekend to play with their toys. They have a right to be upset if their toys don't run as expected. They will complain that their friends rode their toys, while they sat around a campfire or something.