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Hey guys and gals, I’m new to the site but look forward to learning as much from you guys as I can as well as offering my knowledge when I can. I’ve been involved with off-road racing and off-road bikes for over twenty but besides a two month stint on an XR400 in the late 90’s this is the first Honda I have messed with. My son purchased an 06 Crf250r this past weekend that had been sitting for about 7 months. We actually got the bike to run on choke while looking at the bike to purchase. I asked about the history of the bike but the owner had past away so I I could go off of was what the widow knew about it. They struck a deal at $1050 so I thought it was a good deal since we did hear it run. I figured a good carb cleaning and it would be off to the races. I’ve cleaned a hundred carbs before so looking over this one was a simple task. Pilot jet was clogged but got everything cleaned and back together. Tried starting the bike and had no luck unless you use the hot start lever. I adjusted the fuel mixture screw from 1.5 to 2.5 out and still nothing unless hot start is used. My next step is to check the valves which I havnt got to yet but my question for you guys is with this being our first CRF is there anything in particular to look for with this model and year. Or any other suggestions would be appreciated.

Welcome to the site !!

2 things come to mind ..... 1st , you did not mention if you put FRESH Premium gas in it , these bikes will not run on "old" gas , old meaning over 2 months , 3 at best unless its non Ethanol (which since the jets were clogged , I will assume it was Ethanol gas in it) , so first things first , make sure it has FRESH Premium ......

2nd , it is possible that the Intake valves have zeroed or are close to zeroed out , if they are under 0.004 it will be tough to start and act/sound lean by backfiring , etc

To check the valves remove the obvious , seat, tank , valve cover ...... (it is easier if you remove the plug at this point to turn the engine over easier by hand) , on the Ignition side there is a small round plug , remove it , on the Clutch side , there is another , but larger round plug right below the water pump , remove it ....... , now turn the engine by hand until the cam lobes are facing about 2 O'clock towards the rear of the motor , ..... now look and confirm that the 2 slash marks on the cam sprocket are level with the head , the front slash should be inline with a arrow on the cam tower , and the small hole on the Ignition side should have a mark aligned , as well as the clutch side hole should have the dot and arrow aligned , all need to be aligned at the same time , so work the engine around till this is the case , along with the cam lobes facing 2 O'clock

Your valve lash should be
Intake: 0.005 , +/- 0.001
Exhaust: 0.011 , +/- 0.001

Report back with findings ......

Thanks for the tips. I’ll get a chance tomorrow and and see what king of clearance’s I have. As far as gas goes the tank was empty when we got there and the seller gave us a can of gas just to try and get it running. I’m sure it was just some cheap 87 and even it smelt old. I’ll definitely drain that out and put some good stuff in it

Had some time today so I checked the valves. Intake are both measuring .006 and exhaust is left side .008 and right is .009. Timing looks to be spot on. I put everything back together and drained the tank. Put fresh premium in it and after about three kicks it fired up. Did some adjusting on the carb and now have the bike idling on its own. There are still some issues I’m having with the bike while it’s running. I believe it’s in the carb bike backfires a little on deceleration and but my biggest issue is when I let off the throttle the bike still revs for a little longer. Any thoughts on this. I’m planning on a complete JD jet kit and new diaphragm. Any thoughts are appreciated

What is your Fuel Screw set at ??? , it should be around 1-3/4 out , if you have to go more out than 3 , then its too lean on Pilot , if you have to go less than 1 turn out , it is too rich on Pilot , it is possible that the pilot is still clogged , and/or you have a exhaust leak (that will also cause a popping on decel) , the other possibility is , it is popping because you are revving it on the stand/no load on the engine ..... try riding it around and see what it does , see if it bogs , and/or pops on decel then ......