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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.
Any damage to the valve seats or the head casting? Try to find a specialist cylinder head shop that has SERDI equipment (and knows how to use it).
If you supply it to them stripped down with the relevant pages from the manual that should be OK.
 

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Discussion Starter #43
Any damage to the valve seats or the head casting? Try to find a specialist cylinder head shop that has SERDI equipment (and knows how to use it).
If you supply it to them stripped down with the relevant pages from the manual that should be OK.
Yea I think I'll find a specialist. Any idea what might have caused the hole in the piston? The bike only has 11k on it and was full on fluids during the 250 miles that I owned it.

There are high conpression 250 kits and bore out 300 kits available. Since Ive got everything tore down maybe I should try one of those, my only concern being the reliability of either of those options
 

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... Any idea what might have caused the hole in the piston?...
Back when this no start problem first came up, you found the spark plug loose in the cylinder head, right? That air leak directly into the combustion chamber would have caused a lean condition, and in time that can definitely burn a hole in the top of the piston.

Your other option to rebuilding this engine, is to find a complete engine from a crashed bike on e-bay... they are starting to show up from time to time. Might be cheaper in the long run.
 

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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.
You mean to say that you may have had the kill switch in the off position instead of the on position? The kill switch has to be in the on position for the engine to be able to start.
 

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Tried it again this morning. The Kill switch has been in the correct position during my attempts to start the bike. A big clue is that you can hear the fuel pump go through a charging cycle when the switch is turned from off to on. Would have been nice if the solution was so simple.
How easy is it to get to the spark plug cap and to take the plug out for inspection?
Is there a simpler test for compression than screwing in a compression tester (for example sticking a bung in the exhaust and waiting for it to blow out?)
In the past I've used a compression tester and a then a mini compressor and a mechanics stethoscope to trace a leak.
This time the spark plug inspection is as far as I'm going.
1/ Is there a spark.
2/ Is there fuel on the plug.
If the answer is YES to both of the above then alarm bells will start to ring and it's being sent back to the dealers on a trailer. I might do that anyway.Depends on what I find and if the manual can help me to trace the problem quickly. If I can fix it myself I will. I just don't trust dealer mechanics anymore.

David.
 

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Tried it again this morning. The Kill switch has been in the correct position during my attempts to start the bike. A big clue is that you can hear the fuel pump go through a charging cycle when the switch is turned from off to on. Would have been nice if the solution was so simple.
How easy is it to get to the spark plug cap and to take the plug out for inspection?
Is there a simpler test for compression than screwing in a compression tester (for example sticking a bung in the exhaust and waiting for it to blow out?)
In the past I've used a compression tester and a then a mini compressor and a mechanics stethoscope to trace a leak.
This time the spark plug inspection is as far as I'm going.
1/ Is there a spark.
2/ Is there fuel on the plug.
If the answer is YES to both of the above then alarm bells will start to ring and it's being sent back to the dealers on a trailer. I might do that anyway.Depends on what I find and if the manual can help me to trace the problem quickly. If I can fix it myself I will. I just don't trust dealer mechanics anymore.

David.
I'm editing this because I have just gone back through the rather confusing thread which is covering two completely different problems. I don't think ignition issues are your most likely problem. It seems crazy but in view of your comments about no petrol smell are you sure that you didn't accidentally get diesel? If so no real harm done but you will obviously have to drain it out.

If you have any kind of injection problem one way to prove it is to get a can of cold start spray which contains ether ( not to be confused with waterproofing sprays). These are often used to start reluctant tractors etc. If you spray this directly in to the air intake as you turn the engine over it should fire. You can do a similar thing with neat petrol but its a bit tricky to introduce it into the air intake. Incidentally I think the fuel pump will run for a fixed length of time when the ignition switch is turned on so it may stop before the correct pressure is achieved if there is some kind of problem.

The simple test for compression is to press your thumb over the spark plug hole. It should be impossible to keep it sealed when the engine is turned over. As you can't reach the hole on this bike you would have to devise a suitable tool with a rubber tip to do the same thing. Getting at the plug to remove it requires lifting the fuel tank which is not that simple.


Regards Roadster
 

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Yes I thought of starting a new thread but then someone would ask me to search the forum or to not create multiple threads on the same subject. Which does everyone prefer so I can be clear?

I'm going through the diagnosis procedure outlined in the manual which is detailed of page 5-5 of the workshop manual.

Symptom

Engine cranks but won't start (no DTC and MIL blinking)

Diagnosis procedure

1/ Inspect the IACV (Idle Air Control Valve) (located on the throttle body under the tank) (page 5-53)
2/ Inspect the fuel supply system (page 5-33)
3/ Inspect the ignition system (page 18-6)

Also check for

No fuel to fuel injector-Clogged fuel filter-pinched or clogged fuel feed hose-faulty fuel pump-faulty fuel pump circuits.

Intake air leak
contaminated/deteriorated fuel
Faulty fuel injector

I'm going to check the spark plug first though (what size box spanner is needed for this-10mm or 12mm ?)

Please let me know if it is prefered if I start a separate thread/topic.

Thanks.

David.

PS FYI http://world.honda.com/motorcycle-technology/pgm-fi/p4.html
 

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roadster is correct... 16mm hex on the spark plug. A heads up regarding commonly available deep metric sockets: Many (if not most) have a wall thickness which is too great to get down into the spark plug recess on typical Honda motorcycles. All my other Honda single cylinder bikes came with a special spark plug socket as part of the tool kit... the CBR didn't come with one, even though Honda does actually have one for this bike. The Honda P/N is 89216-MAT-000 It has a pivoting hex shaped extension built into the socket... you use a 10mm box end wrench to turn it.

No reason you can't, or shouldn't start your own thread for this no-start problem... I highly doubt you've got a big old hole in the top of your piston like the OP does (lets hope not).

The kind of redundant threads that have become totally unnecessary are the Aftermarket Exhaust, Painted My Heat Shield, What Are The Best Mods For My Bike threads being started on a weekly basis by some of the new members who obviously haven't taken any time to look around at the different forums to see what is already here. Hell, when they do start a thread most can't seem to even figure out the appropriate forum to start them in... I'd say on average I move at least 20 or more threads a week to the forums that they belong in.
 

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Discussion Starter #51
Back when this no start problem first came up, you found the spark plug loose in the cylinder head, right? That air leak directly into the combustion chamber would have caused a lean condition, and in time that can definitely burn a hole in the top of the piston.

Your other option to rebuilding this engine, is to find a complete engine from a crashed bike on e-bay... they are starting to show up from time to time. Might be cheaper in the long run.
That's a sound theory, would the valves have shattered as a consequence of the lean mixture as well? Because the way the edges of the hole are pretty rough seems to indicate that some metal fragments from one of the valves became fused to the top of the piston.... image.jpg

Anyway I just want to have a clear idea of potential causes so that I can remedy the root cause and not have a repeat.

I'm going to take my time considering all options for motor rebuild/replacement. Might as well try the rebuild on my own first and if things go south I can always nab a replacement on eBay. Also interested in putting a larger motor in it if possible, though that may prove difficult with the frame geometry so tight.

Thanks again to everyone that responded, ill post an update a month or two down the line (hopefully) when this thing is put back together.
 

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I'm getting it recovered to the dealers by the AA (Automobile Association). This is classed as a breakdown and is covered under Hondacare as part of the warranty. I'm hoping it's just a blocked fuel filter or faulty pump and hopefully a quick fix.

I'll keep you posted and move all this over to a new post later.

David.
 

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Problem solved by AA. Engine was flooded. Solved by cranking the engine with the throttle almost fully open and listening for changing engine note.
A fully charged battery also helped.
I'll remember to run the engine a few times a week if I can't ride the bike.
Faith in Honda's bikes restored.
AA man says he just never sees these bikes needing help in his job and may never see another.
I'm a happy bunny :).
 
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