Both bikes and motors and sprockets are identical. The only difference is he has a straight short billet and a speed carb. I believe we've found my problem; Im running too rich
If you measured speeds accurately 23 mph to 37 mph is a huge difference
for 2 identical motors.
Get your buddy to swap carbs for a speed run to see the results.
Im not sure when Ill see him next but when I do ill test that
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Im sure you'll have yours running as good or better than the buds bike by then.
Whatever... you're the one that jumps into other posts telling people to buy a whole engine when all they need is a new top end and all then come in here making a big deal about the drill bits that were recommended because somewhere in your mind you think they're junk etc... What about the other post where you HAD to show off a coated piston just because I mentioned an easy way to polish one at home. We both KNOW most people don't have that kind of equipment or the resources to do that so why are you having to show off so much in every other post anyone else besides you are helping in...3 jets at $2.50 each is expensive parts?
He already bought a new speed carb for a lot more.
Actually a 66 jet would be the best bet.
68, 66, 64.
You can't even drill a 68 hole with these bits.
Other people are reading this that don't wanna mess
with soldering jets and drilling them.
Yeah, I posted the chart of jet sizes to drill bit #'s and their sizes.
Quite an ego you have there and looks like you are getting paid by the word?
And when it comes to helping people at all... where are you? ... oh yeah... recommending a whole new engine when they just need a new top end... most likely in the hope somebody will plug your name so you can be the one to sell them this new engine.
I have no ego to worry about, I'm here to help people, not sell them stuff that they really don't need or shoot down what others have already suggested because I came into the conversation late and need to be the center of attention.
I use rosin core since thats what I have, but I honestly don't think it matters, just make sure the jet is cleaned of all oil with some carb cleaner or brake parts cleaner, let it dry for a minute or two, heat jet just enough that solder will melt when it touch around the jets orifice and then just let a very small amount melt into the hole so that it is covered over with solder.
DON'T continue to hold heat on the jet after solder has filled hole or you can actually melt the jet.... ask me how I know...LOL!
made that mistake one time while I wasn't watching what I was doing, was holding jet with pliers and once it got to hot just the small amount of pressure I had on it in pliers was enough for the jet to squish and deform.
I think solid core, rosin core or acid core will all work fine, just get very small diameter solder and just use enough in jet to fill hole and then once it cools for a couple minutes turn jet over and drill new smaller hole in it from the bottom out trying not to wobble the bit side to side as you slowly twist it into solder, if you wobble the bit around in the solder it will get drilled larger than the bit since the solder is very soft.
Id start out with the #73 bit and run the engine for a short road trip and dont just putt it around either, run it down the road a mile or two, and then give her all she has on the way back to the house shut it off, let it cool down for a few minutes and then remove the plug to see what color it is, if its a nice medium brown color and the bike revs good without 4 stroking at open throttle on the flat, then you got it tund plenty good and by then you'll notice an increase in rpms which translate into high top speed and smoother running since the serious 4 stroking will be gone.
You're welcome
LOL.... !!!!!
the hole in the jet is the orifice.
with the jet facing up so you can see the screwdriver slot heat it until the jet is hot enough to melt the solder, do not hold a direct flame on the solder, with a propane torch it only takes a few seconds for the jet to be hot enough to melt the solder then after it has cooled flip the jet over so you have the threaded part facing up and then drill down through solder in middle of jet.
I've never used a torch. My electric soldering gun does fine. You really don't need much heat. If the solder melts when it touches the jet, you're good.
Whatever method of soldering you're comfortable with will work. The important thing is the jet MUST be clean and free of ANY oil residue. Solder won't stick to oil or dirty metal.
Tom
Whatever method of soldering you're comfortable with will work. The important thing is the jet MUST be clean and free of ANY oil residue. Solder won't stick to oil or dirty metal.
Tom
I've never tried it. You can use alcohol or any solvent that will take the oil off.
There is a product made for cleaning brake parts. Brand name is BrakeClean. Any auto parts store should have it. That stuff will cut anything including paint. Be careful and wear eye protection if you use it.
Also I will suggest that you be careful that you don't get any solder on the threads of the jet. That would make it difficult or impossible to re-install.
Tom
The clean out spray should work. Its pretty much pure 99% alcohol in spray form. Its made to dissolve old oil from a gunned up carb.