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Drain the oil, I'm betting you'll see a silver dust of flakes in the oil based on the crack. Catastrofic failure would be my guess, and id bet that you have droped at least one cylinder, maybe more.Only a complete tear down will say for sure. but metal fillings in the oil is a good indicator of a break down in the rotating assem.

  If the oil is clean  then check plugs and compresion.  If every thing checks out, and you think the crack isnt related, then you only have 2 options  either try new plugs and start it or go for the tear down. Either way  the crack needs to be checked out further at some point.

 

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CBR929-jardine race can, down 1, polished frame and swing arm,wheels polished, HELI bars, Sargent seat, Puig racing screen

commuting on a VLX600 shadow for now, 60MPG!!! I punched out the baffles, so it has that V-twin snap and crackle that made H/D so infamous. Except this little scute is rice powered!!lol

and once in a while a 98 gold wing, its a scarey fast 2 wheeled yacht!!

I drained the oil, it came out clean. When i went to check the plug, I pulled out the spark plug cap and the spark plug came with it. The plug looks fine, even the treads look un damaged. almost as if it had backed itself out. It was the plug directly above the crack. I have a feeling something bad happened in that cylinder. Tomorrow ill start tearing down the engine.

Hmmm, you should try  a compression test. Or just put the plug back in and see if it will snug down, if it does then see if it will start. Maybe it just backed out. the compression released through the hole and losing one cylinder would definatly sound different while your riding.

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CBR929-jardine race can, down 1, polished frame and swing arm,wheels polished, HELI bars, Sargent seat, Puig racing screen

commuting on a VLX600 shadow for now, 60MPG!!! I punched out the baffles, so it has that V-twin snap and crackle that made H/D so infamous. Except this little scute is rice powered!!lol

and once in a while a 98 gold wing, its a scarey fast 2 wheeled yacht!!

Thanks for all of your help, it is much appreciated. The compression gauge I have only fits cars, so I put that test off. I did have the top end off and everything checked out, im thinking the problem is somewhat related to the piston. I did put the plug back in, it seemed to seat fine. When I started the bike it sounded horrible as ever. Since there is a crack in the block I figure its easier to swap the engine than to try and fix this mess.

I am considering just parting out the entire bike instead..... Perhaps a new ninja 250 is in my future.

You made the right choice, since that crack means the block is junk.  That crack  probabily goes right through into the # 1 cyl......which means the rings aren't sealing in that cyl  I'm suprised that coolant didn't leak into the cyl/bottom end.  Was the oil level normal?.  Before you install the new engine, I'd do a tear down, and inspect/post pics of the block/head etc.  I only say this so that you can find out why this happened(so your "new to you" engine doesn't end up the same way)  was the gap closed on the plug that came out?

Jeff

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My bike-2002 F4i-With OEM CCT......And no rattle
"Life would be boring if everyone was perfect"

Uncle Jeff, the oil level was fine and no metal or anything in it. Yes the gap was closed. I have no idea what that means so please let me know.

I got the new engine and was too excited to get it running that I never tore down the old one. Well long story short the new one wont start. It just backfires a bit and then quits. I know the engine is good, I rode the bike it was in around the block before i bought it.

The new engine is getting gas and air. I tried the spark test and didnt see anything. The plugs look good, so im kinda stuck.... I have a strange feeling the ecu is bad, does anyone know how to test if it is or not?

Someone correct me if I am wrong but if it backfires then it is getting a spark somewhere somehow but the timing is off. If you are not seeing a strong spark it could be the plugs, coils, or ECU. Did you replace the ECU as well? If either bike was tuned for timing and the ECU was changed, updated or upgraded and you are not using the same ECU that came from THAT engine it could cause loss of timing. Try grabbing the ECU from thebike the engine came from and switch it with yours to test it... If it works then it does not mean a bad ECU really, it could be the timing. Still there is a big chance yours is bad and it is what caused the first issue... I dont see how but I am not an engine expert... 

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Its easy with 4 wheels...try it with two!

midnightthumper:

Uncle Jeff, the oil level was fine and no metal or anything in it. Yes the gap was closed. I have no idea what that means so please let me know.

I got the new engine and was too excited to get it running that I never tore down the old one. Well long story short the new one wont start. It just backfires a bit and then quits. I know the engine is good, I rode the bike it was in around the block before i bought it.

The new engine is getting gas and air. I tried the spark test and didnt see anything. The plugs look good, so im kinda stuck.... I have a strange feeling the ecu is bad, does anyone know how to test if it is or not?

Long story short...The piston definetly smacked the head, closing the gap on the plug.  What lead to that end result will just be speculation, until you tear down the motor, and post pic's.  Either way, the motor is NFG.

So what did you get with the new motor?   Was it just a plug and play?(plug in your harness, and ECM)?

Jeff

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My bike-2002 F4i-With OEM CCT......And no rattle
"Life would be boring if everyone was perfect"

The new motor I bought was just a motor, no wires, no computer, no carbs. It ran just fine, I got to ride the bike before the motor was removed.

However, I did tear the old motor down last night. I think made a mistake in buying a new one so soon. That crack is just a  superficial burr, probably from when honda casted the block. And with the heads off and I spin the motor, everything is just fine. There is no damage anywhere inside the motor and when I spin the motor with the heads on, the cams operate everything fine also. I think the spark plug may have been the issue, but what caused the gap to close I have no idea.

I can post pics of what ever you want if you think it will help figure out what cause the problem initially. But as of now, im starting to think I have 2 good engines.

Yes maybe the crack is unrelated(just superficial)......but something had to close the gap on the plug......And yes everything might appear to be ok, but pull #1 rod/piston and see what the bearings look like.  Also, is there any marks on the piston where the pocket is for the plug?(centre of the piston)    Look at the chamber on the head for #1 cyl. is there any marks/evidence of the piston making contact?  You did state that the engine sounded like it was only running on 2 cyl's......what caused that to happen?, and yes the closed plug will stop that cyl from working...making it sound like it's only running on 2 cyls..........but again,  what closed the gap on the plug?

Jeff

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My bike-2002 F4i-With OEM CCT......And no rattle
"Life would be boring if everyone was perfect"

How did you perform the spark test?  If it backfires...something has to be firing the air/gas mixture.  What do the plugs look like?  Remember if you try to ground the plug on the valve cover, it will not be grounded/fire at all.....since there's a rubber gasket between the cover and head, so you will need to ground the plug on the head. 

You should post some pic's of the old motor.  If it was the piston that closed the gap on the plug, you'd definetly see marks on the chamber of the head, since the gasket is around .030"-.032" thick, and the deck height will be around .004"-.006"...which means the piston would have to have travelled at least(minimum) .034" past it's normal height, so there should be some sign of failure.....because I know there's still clearance between the plug and piston.  I checked it out by placing the piston on top of the head to see if there was clearance when building my last motor.....which means the piston would have had to of hit the head pretty hard........Now.....whether it was from rod bolt fatigue, or the rod itself I can't tell you without looking at it.........if it was the bolts you should see something on the bearing also....you could measure the rod bolt stretch, but Honda doesn't give you any specs to compare your measurement to...I guess you could measure all the rods...but you'd have to aquire a rod bolt stretch gauge( ARP sells one), and it's not cheap.

Jeff

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My bike-2002 F4i-With OEM CCT......And no rattle
"Life would be boring if everyone was perfect"

Here is the pic of the cylinder that the closed spark plug came out of:



I couldnt see any signs of it hitting the spark plug. But I do agree with you, something had to close the gap on it. Just what?
Here is the closed spark plug on the left and one of the other ones on the right:



you may have to click it to make it bigger, but you can definitely see a difference. Its not closed all the way so im thinking the piston didnt hit it that hard.... I couldnt get the camera to focus on the tip of the spark plug, because the tip has no signs of being hit. Ill continue disassembly of the motor possibly this weekend if I have time.

When this motor started sounding like it was on two cylinders I was mid corner at the race track. I had been aggressive on the throttle all morning, but nothing out of the ordinary.
As far as the new motor that wont start. I re did the spark test and im getting spark from cylinders 2 and 3 and nothing from 1 and 4. I used the same plug and coil testing all 4 of the connections. On impulse/frustration I ordered another ecu from ebay on the hopes that its the problem.

Don't bother tearing down the engine any farther....the piston didn't hit the plug..........when I said was the gap closed....I meant closed.........   Like as in no gap whatsoever.  I'd just buy a new set of plugs, a head gasket and put everything back together.

Doesn't Your bike have a CDI box, not an ECM?  I could be wrong.......

Jeff

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My bike-2002 F4i-With OEM CCT......And no rattle
"Life would be boring if everyone was perfect"

Yes mine has a cdi, I just use ecu ecm cdi all interchangeably. I know better im just lazy. Thank you for your help, I appreciate it.
Ill rebuild that motor and let you know.