CR250 Stumped! I hope you are smarter than me!

VinceHayward

Member
Nov 24, 2002
3
0
Bike: 1992 (yes 92) CR250
Problem: Bike wont start.
Symptoms: Pops like it wants to start, and even runs for a short amount of time. MAJOR kick back on the kick starter, almost like it is back firing or something. I appears that the timing is WAY off, but it is not adjustable.

Background:
Bike had a crack in the frame. Previous owner had it welded by a prof. welder and it has not run since. We replaced Stator and CDI module as both of these tested bad. The bike has good spark, compression, and the carb has been re-worked twice.

Attempts to fix:
1. Double check install of CDI and Stator assy.
2. Check Fire with tester that shows spark.
3. Check compression.
4. Check Power Valve operation.
5. Rebuild Carb.
6. Check flywheel and it's placement on crank.

Am I missing something here? This thing kicks like a scalded MULE when trying to start it. I am afraid of breaking my ankle sometimes. It pops, and smokes a little but never really starts.

Any suggestions?
 

mxneagle

Member
Jan 7, 2001
320
0
Have you checked the reeds and the piston skirt? I'll bet the frame was welded with the ignition components still on the bike and thats way the cdi and stator were bad.
 

02'Cr Rider

~SPONSOR~
Nov 20, 2001
216
0
Put a brand new plug in it,try kicking again.If it dont start,Check to make sure its getting fuel to carb,pull off hose to see if fuel comes out.If all good,then find a paved road with a good steep hill and push start it in 3rd gear.Good luck!!!!!
 

Nevada Sixx

Member
Jan 14, 2000
1,033
0
may recheck your wiring to make sure cdi and all is plugged up correctly,, was this a new cdi and stator that you ordered? specically for your bike? where at on the frame was the welding done? was it running well before the weld job? is your pipe plug out? (if you use one)
 

jmics19067

LIFETIME SPONSOR
Jan 22, 2002
2,097
0
Originally posted by VinceHayward
Bike: 1992 (yes 92) CR250

6. Check flywheel and it's placement on crank.



Any suggestions?

does that mean you checked the woodruff key to make sure the sides where perfectly flat. if the edges of the key aren't straight that will throw off your timing a bit, when this thing pops back thru the kickstarter trying break your ankle it sounds like the timing is too far advanced to me.
 

CR Swade

~SPONSOR~
Jan 18, 2001
1,764
5
I had the same problem in a CR125 rebuild I did-turns out the pipe had a mouse nest in it. It would run long enough to plug up @ the stinger, then die, followed by backfiring.
 

VinceHayward

Member
Nov 24, 2002
3
0
Originally posted by Nevada Sixx
may recheck your wiring to make sure cdi and all is plugged up correctly,, was this a new cdi and stator that you ordered? specically for your bike? where at on the frame was the welding done? was it running well before the weld job? is your pipe plug out? (if you use one)

YES, rechecked CDI/Stator wiring. (4 times!)
New CDI, New Stator. The OEM stator is no longer available from Honda. Honda showed a unique partnumber for that year stator. The aftermarket companies show 92 being the same as 90-92 (or something like that) and that had me a little worried. I placed several calls and was ASSURED to the point of beign rude that it would work fine on a 92. One individual went as far to say that he owned a 92 cr250 and he ran one of his stators with no problem. It was kind of hard to argue with that.

I dont have a pipe plug, but I am starting to think that maybe their is a restriction. Although when we pull the bike to try and strart it, I do see some smoke coming out of it.

The guy helping me is a 10 year honda tech and he is very stumped/aggrivated at this point.

Do you think pulling the jug would be the next step??
 

smarttoys

Sponsoring Member
Apr 29, 2001
199
0
I would be skeptical of the aftermarket stator. I have past experiences with faulty aftermarket stators. Spark timing off, kickbacks, backfires, etc... The only way to be certain is to check the timing with a light. You could use a degree wheel and dial indicator to find a rough estimate of where spark timing should be(unless you know the exact timing spec), make a couple marks on the flywheel that you can see with a timing light and kick it through. The marks should coincide somewhat.

Compare the stock stator to the new one. Are the mounting holes in the exact same position? If not, they can be filed a little. Are the pickup coils in the exact same position?

I would verify ignition timing before tearing your motor down. It did run well before the weld job, right?
 

Luft

Member
Dec 24, 2002
105
0
You might take the muffler off and try again. Then maybe take the pipe off and see if it wil fire. Where was the welding done?
 

webbrace

Member
May 18, 2000
63
0
Also make sure you dont have anything stuck in the pilot jet in the carb. Old gas or just some junk floating around will make it tough to start.
 

Vytas

LIFETIME SPONSOR
Oct 31, 2001
256
0
I had taken off my CDI unit to clean out the air box.  Put everything back together and could not start the bike, kicked it about 50 times and then tried to push start with no luck.  Pulled the connector off the CDI and found that I had bent one of the pins in the CDI.  Straightened it out and bike fired right up.
 

baxterj787

Member
Oct 4, 2001
36
0
I'm somewhat sceptical of aftermarket ignitions, especially one that fits 90-92 CR250s. The main reason is that Honda redesigned the engine in 1992. About the only carryover parts from 91 to 92 were the drain plug and the clutch plates. 92-93 parts interchangability is OK.

How much compression do you actually have? Compression gauge reading after about 10 kicks at wide-open throttle shoulde be at least 150 psi (at or above 175 would be better). An earlier post questioned the reeds- check 'em. Your symptoms point to either worn reeds or the other previously mentioned worn woodruff key. I had a KX that did that trick years ago. Took a while to find. A stuck powervalve would not prevent the bike from starting. If it were stuck open, you would expect lethargic throttle response, but it would be consistent.
 

mdmader

Member
Oct 9, 2001
31
0
Look like you've had a lot of help but let me add my 2 cents worth. I have a 91 CR250 that doesn't like to start sometimes. A bike has to have three elements in order to run, fuel, air and fire. I know you have checked some of these, but humor us, we're trying to help.

First, you should be running a BR8ES or BR8EG NGK plug and make sure it is new. Take the plug out and set it next to the cylinder and kick the bike over, make sure you are getting a good center spark. If the spark is weak or nonexistent, check the CDI or kill switch. If the Kill switch is bad then it could be cutting off the spark before it gets to the plug.

Next, make sure the air filter is clean with fresh filter oil. The filter just needs to be "wet", not dripping.

Take out your carb and soak it in carb cleaner overnight. Then take the bowl off and check the float height to see that it is within spec. Make sure that no debris is in the bowl. Next, remove the pilot and main jets and use blast of air to make sure that there isn't any debris in there.

Before you put the carb back on, remove the reed cage and check the reeds. There shouldn't be any gaps between the reeds and cage. Check for any chips. If they seem to be in working order, put the reed cage back on along with the carb.

Put the carb back into its original settings. If I remember correct, the initial setting for the carb is one and a half turns out on the airscrew. The choke should be six turns out as well.

If you haven’t found any issues by this time, you should be ready to give it a try. Hold the kill switch down and give the bike a couple of good kicks in session. Then release the kill switch and give bike a nice long kick from the top. You may have to kick a few times but you should get some indication if it is going to fire or not.

If you still can't get it to start, you may want to check the head pipe to see if it is firmly seated. Those bikes have a cheesy ring that can sometimes flatten causing an air leak.

My only other idea is that you have a leak down into the case. But this is not indicative of your compression tests. Just a thought.

If none of the advice works, then I'm baffled. Good luck and let us know if you resolve your problem.

-M
 

smarttoys

Sponsoring Member
Apr 29, 2001
199
0
A bike has to have three elements in order to run, fuel, air and fire. I know you have checked some of these, but humor us, we're trying to help.

It should be compression, fuel and a timed spark(I know, I'm getting picky). My reply goes off of the fact that he claims it ran fine before the stator and CDI were damaged. Compression and fuel won't do much without a correctly timed spark. Yes, basic things should be checked but a 10 year Honda tech (who is helping him) should have helped him cover the basics already. ;)
 

mdmader

Member
Oct 9, 2001
31
0
Originally posted by smarttoys


It should be compression, fuel and a timed spark(I know, I'm getting picky). My reply goes off of the fact that he claims it ran fine before the stator and CDI were damaged. Compression and fuel won't do much without a correctly timed spark. Yes, basic things should be checked but a 10 year Honda tech (who is helping him) should have helped him cover the basics already. ;)

I do agree with you on compression, however he did state that compression was checked. Believing that, I omitted it from my dribble of possibilities. However, you do bring up a very good point. A timed spark. On the 92, can you advance the ignition timing on it? I’ve not messed with mine, or any bike for that matter. It may be worth looking at again.

Since he stated that the bike backfires, my experience is that this happens because of either the ignition or the carb.

Take it for what’s its worth. Just my two cents…
 

smarttoys

Sponsoring Member
Apr 29, 2001
199
0
I don't know if the holes are slotted on the '92 CR250 stators but they are on the '00-'03 models. My concern is the fact that it's an aftermarket stator and who knows if it's made to exact specs. If the mounting holes or the pickup coil is not in the exact same place as the stock one the timing will be off. Mounting holes can be filed to make small adjustments if needed. It may not even be what's wrong with the bike but I have been bitten in the past with new aftermarket parts. Timing should be verified if he has good compression, good spark and a clean carb with fresh fuel. Especially since ignition components were replaced.:thumb:
 

VinceHayward

Member
Nov 24, 2002
3
0
Thanks for all the great suggestions. I will let you know if we come up with anything. Remember, the bike was running great before the welding was done. The main thing that has me concerned is the HUGE kick back of the engine/kick starter. I just keep thinking that it HAS GOT to be spark timing, but who knows? I will keep at it!
 

bscottr

LIFETIME SPONSOR
Sep 20, 2001
1,255
0
You also may want to check that the coil and grounding wires from the CDI are well grounded to the frame. If the welder caused arching, maybe it affected the ground.

Did you already check the reeds? Also the reed block to make sure it's not sucking air?

Good Luck.
 

mibdv6

Member
May 10, 2003
2
0
sounds trivial but check your plug cap/connector. a friend of mine spent alot of time trouble shooting an erratic spark and it turned out to be the cap.
 

frankrock363

Sponsoring Member
Jan 21, 2004
60
0
Don't asume your new parts are any good.I have gotten many automotive parts starters,alternators,sensors that were bad right out of the box.It does sound like a timing problem double check your new components.
 

Moto Squid

~SPONSOR~
Jul 22, 2002
853
0
ditto about new, bad parts. Call the company(s) they came from and ask them for a warranty replacement. Explain the whole story and make sure you emphasize that their product was the only part changed. If that's a no-go you could possibly find a OEM one on ebay or some salvage man.
 

adstott

Member
May 23, 2002
65
0
I saw this advertisement in the back of Dirt Rider magazine for a Dirt bike salvage company and at the bottom of the ad they specifically say CDI Boxes, and Stators. Maybe they can get you the oem parts you need.

www.DirtCycleSalvage.com

I've never done business with them so I can't vouch for them but you never know.
 
Top Bottom