Hard Start after oil change
 

Hello.
New rider.
I just bought a GZ250 and when I got it, had good power and started right up.
I changed out the oil filter (K&N) and oil with Valvoline 4t 10w40 motorcycle oil, and it felt like it had an easier time running. At first felt like it had a bit less power, but over a couple days, it's difficult to start. It's possible, but it takes me holding the starter down for like 20 seconds before it starts.
Then slowly builds rpm and power.
Any ideas?

Hey there! Welcome.

The oil and filter should have little-to-nothing to do with your hard start issue.

How many miles are on the bike? How does the gas tank look inside? And have you pulled the spark plug to see what kind of shape it's in?

It also might just be that you need to apply a little choke first thing in the morning as it is getting cooler now. When it is cooler, my bike can be a little hard starting so I go about half choke and it will start right up and then as it warms up, you can back it off until it idles without choke at all.

Good point, I didn't even think about choke.

If you happen to be new to riding, it's an often overlooked little tool that automotive drivers haven't had to think about in like 40 years. ;)

You put too much oil in it.

Good point.