[TexasUSA]

Howdy

I have a 04 CRF250x. Previous owner did some mods - "red wire," opened air box, added R&D flex jet and removed baffle. I've had the bike for a couple of years and it's always run well. I recently bought a dual sport kit and put the baffle back in. I rode it for months this way- no issues. Always in warm weather.

The bike sat for about a month (common for me)and I decided to fire it up last week. Nothing. Almost as if the kill switch was engaged. I checked the plug - it was pretty dark, but was firing. I was also getting gas.

Frustrated, I bought some starter fluid. Bike fired right up but the idle was crazy. It was going high and low in waves and would only run on choke. The header got red hot as well.

I know nothing about carbs and jetting, but that seems to be the issue.

How do I start to troubleshoot this? I fiddled with the idle screw and R&D enough to not know where they were set originally.

Any help would be greatly appreciated. Thanks!

[mossman77]

Could be bad gas or clogged jet(s). You could start by draining the fuel and putting in some fresh fuel. Baseline for the fuel screw is 2 turns out from the fully seated position (maybe it's 2-1/4). So turn it CW until it seats, then CCW 2 turns. To set a baseline for the idle screw, pull the gas tank and access the TPS sensor. Disconnect it and probe the terminals with a multi-meter. Adjust the idle screw until your meter reads about 650 to 700 ohms. Reconnect the TPS, put the tank back on, and try to fire it up again. Choke on, TDC (rotate kickstart until it clicks), whack the throttle three times, hit the magic button.

If no dice, pull the carb and give it a good cleaning. Check the float level, replace gaskets, o-rings, and floating seal (available from CRFsOnly.com for $16). Make sure your hot start plunger isn't stuck open, which will cause a lean condition (hot start lever should have a bit of freeplay and snap back after pulling and releasing). Also a good idea to check your valves. Get the service manual if you don't already have one. It will help immensely. It's pretty simple. Hardest part is getting the carb off the bike.

[TexasUSA]

Thanks! I'll give it a shot and report back

[TexasUSA]

Finally pulled the carb (that's quite a process) and a clogged jet was the culprit. I cleaned it out and gave the full carb a good cleaning. Back together and fires right up.

Thanks for the help!