Trying to diagnose why it's not starting

[mrfrenchi]

Hello! New rider here trying my best. Apologies if I don't provide enough info.

Bike Backstory: Dad had a 2005 Ninja ex250 that hasn't run in about 12 years. Just got my endorsement and want to get started on the cheap/ not be tempted too much to speed, but rather learn how to ride properly.

Initial Success: Bike did not have a carb so I bought a motoku carb and installed. I did turn over and run, but immediately started reving to red line. I had pinned the throttle cable and adjusted it so it wasn't so taught. Painted the gas tank, masked off all the holes, took my time, and after install hasn't started since.

Checked:
-The sparkplugs were fine but replaced for good measure
-Did an oil change and changed filter
-Petcock is giving gas
-Float bowl has gas in it and pours out from drain valve on carb

It sounds like it wants to start. (I've been trying with an opened choke and then bringing it down but no dice) I saw somewhere that changing the carb jets may help. The Motoku did come with an extra set, but I wanted to see if there is anything else I should attempt first. Any thoughts? I'm tired and I just want to hear my fancy lawn mower engine. I'm about a week away from just buying a triumph 400 and lighting this thing on fire. Thanks in advance

[Triple Jim]

Hello Justin, and welcome!

Revving to redline indicates that something was keeping the carb slides open when they shouldn't have been.

Starting with aftermarket carburetors opens a big can of worms. To get them working you'd need to plan on a full carb tuning including optimizing all the jets and the needles, and maybe even the diaphragm springs. If I were in your situation I'd talk to Ducatiman here on the board to see what it would take to get a set of restored OEM carbs.

What do you mean by "Float bowl has gas in it and pours out from drain valve on carb"?

Have you done things like check compression to get an idea of the condition of the engine?

[mrfrenchi]

Ok well I guess I signed up for more than I thought... but hopefully I can harness a new skill. I do have a parts bike that has an oem carb that I may go steal instead.

The drain that's on the bottom of the carb has a screw that I loosened and that was able to pour out some gas and check if there was any particulate in it. I can add a picture when I get home later

Appreciate the help and giving me a direction to go in!

[Triple Jim]

If you're going to use carbs off a parts bike, the chances are very high that they'll need a thorough cleaning and maybe a replacement of rubber O-rings and gaskets. Here's some information about what needs to be cleaned:

https://n4mwd.blogspot.com/2013/10/s...-passages.html