Honda CRF250R won't start

Amateur Hunter · #1 03-28-2017, 07:30 PM

My son recently purchased used 2006 Hondra CRF 250 R,
He tried it out before buying it and it did work good.
But when he brought it home it wouldn't start.
Changed spark plug, bike did start, but once he shift it into gear it diet.
And won't start again

Any ideas what could be wrong with it or mechanic around Red Deer ( that does not include ripoff crew aka Turple Bros

tullfan · #2 03-28-2017, 07:39 PM

This model is notorious for valve clearance issues. I beleive it's every ten hours of running time to check clearances. The cams are more pizza shaped than egg shaped(exagerated), and they pound the valves into the head. Anyway when they get tight the bike is really hard to start if it even starts. If it dies when you put it into gear, could be a sticky clutch. There's no safety interlock to prevent it fron dying when in gear or clutch is let out.
After valves are checked, spark should be ok as you said it ran, next check fuel. I highly suspect valves though. Start there.
Tullfan

ronkaren · #3 03-28-2017, 07:52 PM

i own a 06 honda crf250. it was hard starting from new. once it's started leave it idle till hot, or motor will boog and dye. i have had valve clearance checked several times and so far they have not needed adjustment.
i own a couple honda quads, lawnmower, generator, snowblower and pressure washer and all start great. only ever had problems with the crf.

dangerranger5143 · #4 03-28-2017, 07:58 PM

I had the same model of bike but it was a 2004. Bought it in a box and rebuilt it myself. Ended up having the valve seats ground and installed a set of kibble white valves. The stock valves are super hard on the aluminum head. As mentioned fuel is a big factor too. I only ran my bike on premium. If the bike has being sitting for a while the carb and jets could be built up with gunk and not allowing it to run properly under load. I did all my work myself and know a few talented bike mechanics if you are interested.

DR

sigma1 · #5 03-28-2017, 09:28 PM

I have a xr400 that was hard to start. I went up one size on the pilot jet now it starts good but you have to really let it warm up good or it will die when cold. I would clean the carb and check what jets are in it. Then move onto the valves. Put in a new factory plug with proper gap. Sparkplugs can test good but still not work when put in the engine. Youtube has good videos for instruction.

dewalt18 · #6 03-28-2017, 09:50 PM

I'd be willing to bet tullfan nailed it. Not limited to this model, all of the "new" four stroke mxers are very finicky when it comes to valve clearances. Hit your local dealer, grab a service manual and a Hotcams valve shim kit, and get it tuned in. Have seen many bikes go from barely running to starting on first kick, just from a tune up.

lmtada · #7 03-29-2017, 07:03 AM

Two strokes rule.

lmtada · #8 03-29-2017, 07:32 AM

Don't by used 250F. Buy used,450F. Buy used two stroke (cheap to fix).

Huntnut · #9 03-29-2017, 08:26 AM

If it idles fine when running then probably not the valve clearance. Not wanting to idle and hard starting are signs of insufficient valve clearance. These things are notorious hard starters when cold. For easier cold starting open the throttle wide open quickly a couple of times as this will cause the accelerator pump to shoot some raw fuel into the intake. As stated let it warm up properly. The stalling when putting it into gear is caused by the clutch plates sticking together caused by the cold oil. One way to alleviate the problem is to get the bike rolling before putting into gear, once in gear and moving pull in the clutch, rev the engine and hit the rear brake-this will break the clutch plates free and it will be good after that.

Dave P · #10 03-29-2017, 08:56 AM

Clean That Carb.

BackPackHunter · #11 03-29-2017, 09:00 AM

I would dump the old gas , add new
If it will start and idle let it get warm as stated
If your son isn't overly experienced with MX bikes the clutch isn't like a trial bike
It wants gas, but let out the clutch to fast n he'll be watching his bike ride away

So hold a little throttle and let the clutch out at the same time
If still nothing , go get some feeler gauges
Watch some YouTube videos on checking the gap
It's very easy , if the clearance are out out can buy a shim kit

But I think he's not use to a clutch on race bike

If you can't figure it out, you can bring it to my place and I'll check the valves and carb for a box of Beer

BackPackHunter · #12 03-29-2017, 09:07 PM

Exhaust valves where out .005 😳

dangerranger5143 · #13 03-29-2017, 09:26 PM

Just curious but did that fix the issue? I had a chat with a bike mechanic I work with today and he was leaning more toward clutch not set properly or clutch discs sticking like mentioned above. Some guys run a heavy weight oil in the gear box during spring and fall and can cause this issue.

DR

vinny · #14 03-30-2017, 05:49 AM

If shifting it into gear kills it, it's got nothing to do with valve clearances. It's the clutch. Tear into that to get to your problem.

elkhunter11 · #15 03-30-2017, 07:39 AM

Quote:

Originally Posted by vinny

If shifting it into gear kills it, it's got nothing to do with valve clearances. It's the clutch. Tear into that to get to your problem.

People seem to be getting hung up on why it stalled, not why it wouldn't start again.

BackPackHunter · #16 03-30-2017, 08:36 AM

When the bike showed up, I started it 1st kick
And took it around the block , ran pretty ruff
Ill shim it today
(Have to go get a shim kit , I run 2 strokes so this is never a problem for me)

sigma1 · #17 03-30-2017, 10:03 AM

Good maintenance to use fresh gas and clean the carbs and fuel cock. Check the jet sizes for lots of people put on a low restriction air filter and it can lean out the engine because of the extra flow. Watch your plug color for the first few hours of riding. White is lean and dark is rich. Jet accordingly.

BackPackHunter · #18 03-30-2017, 09:20 PM

Timing , shimmed and carb clean
Bike runs good now

dangerranger5143 · #19 03-30-2017, 09:54 PM

Good to hear. Hopefully you just bought the shins needed. I know they're pricey. I have a basically full hot cams kit here you could have had you pick from had I seen this early.

Good on you for helping out another member.

DR

bb356 · #20 03-30-2017, 10:30 PM

Quote:

Originally Posted by BackPackHunter

Timing , shimmed and carb clean
Bike runs good now

Cool !!!

sigma1 · #21 03-30-2017, 10:53 PM

Excellent your sons bike is running, now what are you going to ride?

BackPackHunter · #22 03-31-2017, 07:23 AM

Quote:

Originally Posted by dangerranger5143

Good to hear. Hopefully you just bought the shins needed. I know they're pricey. I have a basically full hot cams kit here you could have had you pick from had I seen this early.

Good on you for helping out another member.

DR

Not being a 4 stroke guy I had no idea pricing on the kit. ($140)
So I turned around went home and figured out what I needed
$5 each seemed better .