: Hi I have a stock fl350 with a brand new dg pipe I am having problems with getting the jetting right I have the stock 142 and 45 jets in it right know, I wasn't sure what jets to get for it because I put a brand new spark plug in it and tested it at a quarter throttle for about 300yds and I checked the spark plug and it was white. so if I could get some help that would be amazing. Im at a 500/1000ft sea level/, I live in Michigan also it is a stock 32mm keihin carb. Also have a brand new uni air filter

STOP RIGHT THERE.
Don't even drive this thing until you have done a flow test on your fuel pump.
You need to get 4.5oz in 10 seconds at idle. Use a stop watch.
In the past many of us just used the starter for this test but it was difficult to get this flow rate due to the many variables like battery condition and starter condition. So do it at idle.
Here is one of my videos on it: https://www.youtube.com/watch?v=WT-rBlEb8Z4

NOTE: you will have to attach a hose directly onto the output of the pump and into a measuring container. The reason for this is that the original hose has a bypass on it that goes back to the tank so that would screw up the test. It's also easier to do it this way.
Once you have that test done you can go to jetting.

There are many many threads on this site about blown engines. There is a reason -- fuel and fuel flow. Lack of fuel flow on a two stroke is deadly. You lean the Engine out and then it melts the piston.
Another important factor is octane rating. The stock oddy is and air cooled Engine and it's located behind a seat. I don't know what kind of smoke they were on when they came up with this idea. The engines run hot in these things because of it and it elevates the intake charge temperature and this causes the fuel to detonate if it has low octane. I run AVGAS.
You have been warned. I don't care if you listen to me or not. Trust me, I have experience.
CO

STOP RIGHT THERE!
You have a DG pipe and UNI filter, no longer stock.
you will likely need to richen it up with bigger jets, better to start rich and move back than to damage your Engine and start over.
I second the use of AvGas, cost a bit more in the short term but can save big in the long term, IMO.
reading plugs is a science, I have never been very good at it and I don't usually tune for optimum performance, if the plugs are not fouling and your are not melting pistons then you're in the ball park, LOL.
I would start by going up a couple sizes on the main jets, as CO mentioned, use the search feature and check for other posts on jetting and do check the condition of your fuel pump, a weak pump will give you problems.

And welcome to the forum, so much information here.

Hey CO, the link to your fuel pump test is not working?