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No problem wish i could help more. Plus it gave me a reason to go out and get the bike ready for a ride this afternoon once the sun comes out.
 

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anybody think a ecu reset is worthwhile?

if so how can i do it with a bike that wont start?
"They" say you can reset the ECU by disconnecting the cables from the battery, and leaving it disconnected for about half an hour... I read that somewhere (here on these forums?), however I don't know if it's true, or not.

If you decide to give it a try, first make sure that the ignition key is in the OFF position, before disconnecting the battery cables. Disconnect the "positive" (+) cable first, before the "negative" (-) cable.
Otherwise you could end up with a fried ECU if the ignition were in the ON position when disconnecting battery cables.

Whether the ECU reset works and your bike restarts, or not, it might be worth a try. I still have concerns about that loose spark plug, though...
 

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Here's a long shot... What if extra heat from exhaust leaking past the loose plug did something to the coil or plug wire. A weak spark would be visible but not able to ignite the mixture under compression.
 

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Discussion Starter #26
Here's a long shot... What if extra heat from exhaust leaking past the loose plug did something to the coil or plug wire. A weak spark would be visible but not able to ignite the mixture under compression.
@Deanohh, thats a valid point. Im getting a consistent white spark (on both plugs, old and new) when I pull the wire and plug out of the cylinder.

A blue spark would be hotter, so perhaps it should be blue? I don't suppose anyone out there knows the answer to that question from experience with their own bike?
 

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I don't know how to test the coil, but I have had intermittent ignition trouble on bikes before where a new coil solved the problem.
 

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@Deanohh, thats a valid point. Im getting a consistent white spark (on both plugs, old and new) when I pull the wire and plug out of the cylinder.

A blue spark would be hotter, so perhaps it should be blue? I don't suppose anyone out there knows the answer to that question from experience with their own bike?
A good blue spark is what you want... you could very well have a bad ignition coil. I think that at this point you'll need a Service Manual, and a good digital multi-meter to go through all the possible causes for a weak spark. The S/M has a troubleshooting section, which guides you through the various tests to perform.
 

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It is not likely that a 'weak' spark is responsible if there is no hint of the engine firing up. If the spark will jump a 1mm gap to get to earth from the plug body it is not weak. Don't forget that the engine needs air as well as petrol. Make sure the air intake is not obstructed by something being sucked in from under the seat.

In the event of major mechanical issues ( such as valve gear or piston) the engine will have lost compression. You don't necessarily need to check this with a gauge. You can just remove the spark plug and block the hole with a suitable object such as a screwdriver handle held in your hand. When you turn the engine over there should be enough compression to force the said object off the hole. Obviously don't put anything inside the spark plug hole and don't hold it in a way that will go through your hand if it jumps.

Finally if the spark plug is wet you should consider that there could be a huge over supply of petrol from an injector fault. This will accumulate in the engine and you would be able to smell it in the oil. You might also notice that the fuel pump would keep running even when the engine was not being turned over. Normally the fuel pump should stop after a few seconds when the ignition is turned on. If you were getting towards the bottom of the tank when the problem first occurred there is a chance that something got through the fuel filter and lodged in the injector. ( Sugar is the classic soluble contaminant that will do this!)

You can remove the injector and observe the spray pattern ( fire hazard!)

Regards Roadster
 

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I don't know what the op's problem will turn out to be, but if the coil has a problem it might show spark outside the engine but when installed could be arcing or shorting voltage to a nearby point on the bike, or if there is internal defect and its not producing enough voltage, the resistance across the plug gap increases under compression so even though it sounds logical that compression does not increase the voltage needed to spark......it does.

I hope he can have a shop diagnose the true problem and let us know what needed to be fixed.
 

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you 100% sure you have fuel? you can spray some carb cleaner / ether at the airbox see if it runs

key on engine checklight will turn on and off and at the same time hear the fuel pump priming, it will not blink if you are starting it but if the battery is very low it will blink

if you have problems with ECU/SENSOR, put the side stand on, neutral, press starter button for 10seconds, it will blink if ecu detects a problem

to access previous problems stored in the ecu, just remove the low cover of the tail light, access the dtc slot and short the blue and green wires then turn the key on and it will blink the stored problems
 

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Discussion Starter #32 (Edited)
Thanks to all that have offered their advice and insight on this issue....

Recap: Preowned 2011 CBR 250R 11k miles, 200 of them put on by me.

I took the bike to the local Honda shop, and unfortunately the engine has no compression. I was told that this was likely caused by the previous owner running it low on oil or coolant, but it is curious that the motor didn't show any signs of wear during the 200 miles I put on it before it abruptly died on the freeway. Or maybe since I was new to the bike and to motorcycles in general I didn't know any better to be aware of tell-tale signs.

Either way, the shop estimates that it will take $550 in labor alone to tear the engine apart, and depending on whats wrong it could be another $500-$1000 to get it running once again.

So I am seeking advice about my options with this bike. Does it have any value as a rolling Chassis? Is a replacement motor obtainable or a good idea? Could I put a 400cc motor in it if one were available? Is rebuilding the current motor my only choice to get any return on the bike at this point? Maybe I should try to rebuild it myself.

I thought choosing a newer Honda 250 with low miles was a relatively low risk as a used bike. I guess I was wrong :(
 

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Thanks to all that have offered their advice and insight on this issue....

Recap: Preowned 2011 CBR 250R 11k miles, 200 of them put on by me.

I took the bike to the local Honda shop, and unfortunately the engine has no compression. I was told that this was likely caused by the previous owner running it low on oil or coolant, but it is curious that the motor didn't show any signs of wear during the 200 miles I put on it before it abruptly died on the freeway. Or maybe since I was new to the bike and to motorcycles in general I didn't know any better to be aware of tell-tale signs.

Either way, the shop estimates that it will take $550 in labor alone to tear the engine apart, and depending on whats wrong it could be another $500-$1000 to get it running once again.

So I am seeking advice about my options with this bike. Does it have any value as a rolling Chassis? Is a replacement motor obtainable or a good idea? Could I put a 400cc motor in it if one were available? Is rebuilding the current motor my only choice to get any return on the bike at this point? Maybe I should try to rebuild it myself.

I thought choosing a newer Honda 250 with low miles was a relatively low risk as a used bike. I guess I was wrong :(
Do you have the experience and tools necessary to take on the job of rebuilding the top end yourself? If you do, you could save yourself quite a bit of money by going DIY... a new cylinder, piston, rings, top end gasket set will run about $150.00 total from one of the online Honda dealers. Add $70.00 for a factory Service Manual if you don't already have one.
 

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I was faced with the same dilema when my MZ RT125 would not start a while ago. I did a compression test by feeding air from a small compressor into a plug adaptor. The engine failed the test as I could hear air escaping past the intake valves using a mechanics stethoscope.
I stripped the cylinder head myself and eventually got the valves and seats replaced/reground on a SERDI machine (google it!) at a cylinder head specialists.
Lost money when I sold the bike but it was worth the experience and I would not have been able to sell a non running bike anyway.
That's why I've just invested in an ABBA stand so I can do all my own work.

David.
 

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Now mine wont start either.
Last rode the bike 5 weeks ago (off the bike because of a wrist injury).
Tried to start it this afternoon after charging the battery and would not start.
Empty gauge on fuel guage flashing (could hear a small amount of fuel in the tank). Filled up with 5 litres of unleaded (cycled up to the petrol station with a canister).
Tried again and still will not start. The pump can be heard as usual and all the electrics work ok (tacho spins as usual. ABS light ONLY is on, NO other warning light). Footrest is down and gearbox is in neutral. I've tried the full throttle open position as mentioned in the user manual (used to doing this with a carb equipped bike) and the the usual closed position, no joy.
The bike has been parked outside in our 30 degree heatwave for the last 5 weeks (under a black bike over as well-probably formed a kind of mini oven) and I've not run the engine once.
Surely this bike can cope with UK temperatures?
I've noticed that there is not the usual smell of fuel that I normally get when the bike starts. I've not checked for a spark yet. I will do that on my day off on Friday next if no start during the week. Is the HT lead easy to get to? How easy is it to remove the spark plug?
Could this be a vapour lock caused by evaporation of the fuel in the fuel system?
I'm puzzled and my confidence in the bike is a little shaken.I though I'd left all this kind of stuff behind me when I got rid of my MZ.
Unless the mechanics at the dealership screwed up something on the bike when they supposedly did the 600 mile service (still not sure if they checked the valve clearances even though I have it in writing that they say they did).

David.

PS My wrist is on the mend so that's some good news.

PPS. I will try to start the engine again on a cooler morning (instead of a hot afternoon) as I suspect a vapour lock has formed in the fuel system.
 

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Discussion Starter #36
Do you have the experience and tools necessary to take on the job of rebuilding the top end yourself? If you do, you could save yourself quite a bit of money by going DIY... a new cylinder, piston, rings, top end gasket set will run about $150.00 total from one of the online Honda dealers. Add $70.00 for a factory Service Manual if you don't already have one.
Well I certainlly don't have the experience but I'm trying a rebuild anyway. image.jpg


As you can see from the picture I have made some progress. I am a bit tentative about disassembling the motor any further, but do I have to? Having trouble getting the piston to move manually, if I can get it to rise and replace it is there a necessity to go any further with disassembly of the motor? Just trying to learn as I go.
 

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Well I certainlly don't have the experience but I'm trying a rebuild anyway. View attachment 6372


As you can see from the picture I have made some progress. I am a bit tentative about disassembling the motor any further, but do I have to? Having trouble getting the piston to move manually, if I can get it to rise and replace it is there a necessity to go any further with disassembly of the motor? Just trying to learn as I go.
Holy crap... you've got some serious engine rebuilding ahead of you. Just based on the size of that hole in the top of your piston, I'd want to split the crankcase and see what the bottom end of this motor looks like. What does the cylinder head look like?
 

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Now mine wont start either.
Last rode the bike 5 weeks ago (off the bike because of a wrist injury).
Tried to start it this afternoon after charging the battery and would not start.
Empty gauge on fuel guage flashing (could hear a small amount of fuel in the tank). Filled up with 5 litres of unleaded (cycled up to the petrol station with a canister).
Tried again and still will not start. The pump can be heard as usual and all the electrics work ok (tacho spins as usual. ABS light ONLY is on, NO other warning light). Footrest is down and gearbox is in neutral. I've tried the full throttle open position as mentioned in the user manual (used to doing this with a carb equipped bike) and the the usual closed position, no joy.
The bike has been parked outside in our 30 degree heatwave for the last 5 weeks (under a black bike over as well-probably formed a kind of mini oven) and I've not run the engine once.
Surely this bike can cope with UK temperatures?
I've noticed that there is not the usual smell of fuel that I normally get when the bike starts. I've not checked for a spark yet. I will do that on my day off on Friday next if no start during the week. Is the HT lead easy to get to? How easy is it to remove the spark plug?
Could this be a vapour lock caused by evaporation of the fuel in the fuel system?
I'm puzzled and my confidence in the bike is a little shaken.I though I'd left all this kind of stuff behind me when I got rid of my MZ.
Unless the mechanics at the dealership screwed up something on the bike when they supposedly did the 600 mile service (still not sure if they checked the valve clearances even though I have it in writing that they say they did).

David.

PS My wrist is on the mend so that's some good news.

PPS. I will try to start the engine again on a cooler morning (instead of a hot afternoon) as I suspect a vapour lock has formed in the fuel system.
Have you checked your engine stop switch... could it be in the off position?
 

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Discussion Starter #39
Holy crap... you've got some serious engine rebuilding ahead of you. Just based on the size of that hole in the top of your piston, I'd want to split the crankcase and see what the bottom end of this motor looks like. What does the cylinder head look like?
Cylinder head doesn't look too bad, two valves shattered and one of the spring fasteners snapped. A bracket that holds the cam down on one side cracked as well. Think those will all be fairly cheap to replace.

Wondering if someone experienced might rebuild it for a couple hundred dollars since I've done most the work of getting it out. Just opening the crank case is a bit intimidating.
 

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Have you checked your engine stop switch... could it be in the off position?
Yes. Turned it on and off several times and listened to the pump cycling on and off.
I'll check it again tommorrow as I may have had the kill switch on instead of off when I was trying to start the bike.
 
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