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restarting woes....

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ok guys... ive got a very serious question for you. ive had two hare scrambles gone to shit over the bike not wanting to restart after a get off. :applause:

there is nothing more frustrating than driving 5 hours, sleeping in a field, paying your entrance fee, riding your balls off...

and then have the whole race come to a grinding F**KING halt because the bike wont restart. 🤣 so there you sit... positions lost every 30 seconds... getting more and more fatigued.... what a damned waste.

first off- the particulars: CRF250R, stock jetting, sea level (Florida)

situation- fall off the bike. bike is hot and it stalled.

now, can someone tell me what the hell is going on- (is it lean, rich, float bowl dry, etc) that makes this thing such a c**t to start.

thirdly- can someone help me by telling me how to solve this? (get an airbleed screw, smaller pilot, wait and let the bowl fill up, take a piss and let the motor cool down...) Something so i dont ruin another damn weekend!

Many thanks in advance! :banghead:

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yes- i'm fanatical about checking the valve clearances. they are spot on.

ive had this bike for a year now... and usually it starts very well. but after a tip over... she's an absolute bitch.

clearances ok.... i first try the hot start (NO GAS!,hand not even on the throttle)... then i even try the ol' slowly open the throttle to not squirt any fuel) and kick repeatedly with WOT.

then, return slide and hot start... then no hot start... then choke... ANYTHING that might give me some result...

after kicking and kicking in any all combinations of settings- she'lll inexplicably fire on the 40th kick.

drives me nuts!

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to be completely honest- i havnt messed with the air bleed circuit on this bike. it is at the stock setting and i cannot tell you if the idle reacts to it or not.

the reason is- before this bike i had an aftermarket air bleed screw installed on my 450 and tried like hell to adjust it as everyone was saying you should... "listen for a slight rise in RPM at idle... etc etc etc"

and i'll tell ya- ive jetted 250 GP bikes for ten years with some pretty good results... and i couldnt feel a hint of difference with that circuit.

after it backed out and fell off (ruining a trip to Georgia), i decided never again.

tell me i'm wrong- and that it truly is this some sort of $19.95 holy grail that is the next best thing to an electric start....

i'm ALL ears!

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im not going to convince you of anything.im not a salesman.i odnt have extended fuel screws on any of my bikes.but i do have the tool to adjust the screw to tune it.

you have a big starting problem but have not confirmed the proper pilot jet size with the fuel screw.

if your ready to do some testing then we can move forward.otherwise,i cant be of much help other than to tell you i suspect your pilot circuit is rich.

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hey man, i'm sorry if i sounded curt or abrupt... or if i sounded like i wanted a wonder solution but was not willing to experiment or give you any info. i'm just kinda fried. so fried i'm actually thinking about going back to two smokes, this is so under my skin.

i am perfectly willing to try ANYTHING. i will do any testing. can you recommend a course of action?

can you share some of the relations between the pilot and the airbleed?

hep a brutha out

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ok

its not a air bleed.its fuel screw.in is leaner out is richer.

with the motor off turn the fuel screw till it lightly seats.count the turns.record that number.

set the fuel screw at 2 turns out.start the motor and let it get some heat in it.once the motor is warm turn the fuel screw in till the idle drops/misses/or the motor dies.

than go back out just till the idle smooths/peaks.

this should happen between .5 and 2 turns.

if you can turn the screw full in or it has to be under .5 for any reaction you need a smaller pilot jet.

if it needs to be more that 2 turns you need a bigger pilot jet.

go up or down a pilot jet size as needed and retest.

if your current pilot jet is confirmed then i would look toward the ignition.you dont happen to have a trail tech flywheel do you?

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sorry- i stand corrected. fuel screw. post slide.

air bleed- pre slide.

i will try all you suggest to sort the bottom end jetting.

your allusion to the trail tech flywheel intrigued me. i was thinking of installing one because of the favorable effect it had on my 450. it really helped the grunt traction and helped keep it running in the slow stuff very effectively.

your comment- are you in favor of them or an opponent?

also- you mentioned igntion. i put in a new spark plug on friday before the weekend- are you thinking coil? pick up location? advance? vortex black box?

i'm very curious about your ideas here.

thanks for the remarks thus far and many thank in advance for your reply

:banghead:

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trail tech flywheels have caused many problems on 450's.ive had more than one mystery jetting problem cured by removing it.

my gut feeling on ignition would be a stator (source coil) problem.

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ok- last night i tested the fuel screw hypothesis. it appears that the pilot jet is ok.

i started it with 2 turns out. she started to miss after about 1.25 turns in. backed it out about .6 turns until she idled consistantly. at present, she rests at just under 2 turns out.

then i got her good and hot... ran around a bit... stopped, and just let the bike drop on her side. this would simulate a "get off". she puked a little fuel and then stalled on her side shortly thereafter.

stood her up- no throttle- hot start- and kicked. nothing. basically a rehash of another race ruining starting problem. kept kicking... tried to nurse the throttle open and "clear her out". after about 10 to 15 kicks, reclosed the throttle and tried some more...

any help? is there someone that can rewind the stator for a bigger spark? does anyone make a longer kick start for more force/ throw? would either of these ideas actually help? any other ideas?

(all the below is just a bitch session for all the lurkers reading this post. it contains no useful empirical information for solving this problem):

i'm really thinking going back to 2 stroke... but i love the traction, the grunt, the stability, all the characteristics of this bike.

but look at it this way- every hare scramble i started with a 2 smoke i finished either on or 1 lap down from the leaders. basically a 100% finish rate.

on this damn 4 stroke- ive got a 25% finish rate. and am about ready to torch the damn thing.

even watching the AMA motocross guys. their bikes are tits. the best, most carefully maintaned dirtbikes on the planet and you even see them lose races because the're on the side futiley kicking thier brains out trying to start these damn things.

what's going on? and why cant we fix it?

sorry for the bitch, i'm just a little depressed/ maniacal/ suicidal right now :banghead::applause:🤣🤣

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(all the below is just a bitch session for all the lurkers reading this post. it contains no useful empirical information for solving this problem):

i'm really thinking going back to 2 stroke... but i love the traction, the grunt, the stability, all the characteristics of this bike.

but look at it this way- every hare scramble i started with a 2 smoke i finished either on or 1 lap down from the leaders. basically a 100% finish rate.

on this damn 4 stroke- ive got a 25% finish rate. and am about ready to torch the damn thing.

even watching the AMA motocross guys. their bikes are tits. the best, most carefully maintaned dirtbikes on the planet and you even see them lose races because the're on the side futiley kicking thier brains out trying to start these damn things.

what's going on? and why cant we fix it?

sorry for the bitch, i'm just a little depressed/ maniacal/ suicidal right now :applause:🤣🤣🤣

You should buy a Bultaco... He,he! :banghead:

http://i2.photobucket.com/albums/y12/max348/bultaco.jpg

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I've had similar problems, checked the valves and they were fine, I began to worry that it was electrical and had recently installed a 200w rewound stator, turned out to be a faulty kill switch. I'd disconnect the kill switch while testing. That's about all the electronic troubleshooting I have to offer.

When did this problem start?

Don't give up on it now.

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I've had similar problems, checked the valves and they were fine, I began to worry that it was electrical and had recently installed a 200w rewound stator, turned out to be a faulty kill switch. I'd disconnect the kill switch while testing. That's about all the electronic troubleshooting I have to offer.

When did this problem start?

Don't give up on it now.

UTAH- where did you get the rewound stator from? i dont think its as simple as a bad kill switch as pretty much all other times she starts pretty well. its only a hot fall over that she gets so nasty.

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You know, I honestly can't remember who I sent it to. I've been trying to remember and looking at websites but I cannot recall. I've asked a buddy whos also ordered from this same place and he's totally forgotten too. I'll post if/when I remember....sorry. I read the following do it yourself link when I first started looking for someone to do it. http://4strokes.com/tech/honda/brpstatr.asp

Back to the hot fall issue, I'm probably not as knowledge as you in troubleshooting (in reading your posts) but it does seem like something simple is being overlooked. I really wish I had something useful to offer.

It's not a fuel supply problem?

It's not a float level problem?

It doesn't seem like an electrical problem, even after I offered my kill switch idea :banghead: in that the bike has to tip over for it to occur...Does it start easily if the bike is hot but does not tip over?

Have you tried tipping the bike over when it's cold and then trying to start it? Just curious.

Good luck!

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Have same problem with 04 crf250r,spent 30 minutes in Georgia trying to start and the same problem at out local hare scrambles in NY at the start of the season.Mine will also stall when braking hard or letting off the gas quickly after a quick acceleration.I do have a Z-start auto clutch which has not stopped it from stalling.I tried a 13 oz flywheel weight which makes the flywheel weight a total of 29oz,still did not help.Finally started messing around with the fuel screw.I have mine set at 3/4 of a turn out right now.Bike will run when layed down but will still stall when braking hard.Restarts withen 3-4 kicks after stalling.If the bike gets layed down and stalls I will hold the throttle wide open and will restart withen 4 kicks.I always try to make sure it is in neutral,bitch to start in gear.I have done no more adjustments since then,I am just happy the thing starts.I have had 8 races since the repair and have not lost any time due to no starts.

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Rich1554,

thanks for the post. its the only glint of hope ive seen. i just wish somebody could break the problem down for me-

for example: the bike is very hot after an hour of flogging through a harescramble... this being a four stroke problem, is it because intake valve caps the combustion chamber and thus is also very hot... causing the intake chanel to get hot... reducing the density of the intake charge and running it too lean to fire?

OR- you fell over, inadvertantly dumping liquid fuel out of the now vertical float bowl into the intake tract, thus you're too rich/ flooded.

but when you're out on the trail... which course of action do you pursue? choke on and kick? or try to clear the hell out of it?

i dont know. i thought a jetting expert would have a little more insight into this phenomena that we 4 strokers have all encountered... :banghead:

but i guess i'll try to run with the fuel screw adjustments and see how it goes.

hhhmmmm

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