VincentHill
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posted October 22, 2006 03:22 PM
If you do not Check it you can Suspect it!
I have bi Idea of what Happened when the loud explosion happend on the DYno. We all thought I had damaged the Pistons, RIngs, Head Gasket or Valves. I looked at everything and took it apart and really found nothing!
I replaced the Exhaust Valve SPrings to the Heavier Duty ones that I already had over the Intake valves. All of the exhaust valves looked good!
I had the Intake on #1 cylinder out and they looked good also but for some reason I went no farther and did not take out the rest of the Intake Valves after seeing that all of the SHims and retainers were in Mint condition.
Now I wonder "Do I have a Broken Valve SPring?"
FOr some reason the engine is breaking up with a small miss that can be tuned out by leaning the Mixture a few bars on the PC3. BUT WHen I SPray the NOS the engine Breaks up real bad and refuses to handle the NOS.
I was feeling that maybe the Spark Plugs were damaged and were the cause of Missing. I put the Surface Gap plugs in the ZRX and the bike ran perfectly.
I put in fairly new #10 plugs and the ZX12R ran like it was too rich and the timing was retarded. Even the Exhaust system turned darker like a Bike that is retarded or too rich.
Seeing that the Plugs were not the problem I checked the valves for clearance and the tightest exhaust was about 0.008 and the tightest Intake was about a loose 0.005 and the looses Exhaust was 0.10 and the looses Intake was 0.00 7
So as far as I am concerned the Valves are in good adjustment.
One of my wierd thought is that the explosion was so violent that the "Pressed" on Cam SProckets may have shifted and I need to check the Cam timing.
Second, it all really sounds Electrical like the ECU or a Sensor to the ECU or the PC3, but I keep asking myself, How could an Internal explosion damage ANY of these parts??
Any one got any Experience "WHere they FIXED a Wierd Miss??
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Made History @ Daytona and still one fast old man!!
  
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01zx12r
Expert Class
Posts: 338
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posted October 22, 2006 05:02 PM
Vince....
I would have to say what youre hearing and feeling with the bike breaking up on N20 is NORMAL. I know this sounds crazy but as much nitrous and fuel as youre flowing into the air box you will probably have an afr around 9-10 and the bike not wanting to pull past about 9-10k without leaning things out correct? This is a dyno problem only so far correct? Chris
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Lovett Racing/Pedigo Performance
8.40 @170
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VincentHill
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posted October 22, 2006 05:45 PM
quote:
I would have to say what youre hearing and feeling with the bike breaking up on N20 is NORMAL. I know this sounds crazy but as much nitrous and fuel as youre flowing into the air box you will probably have an afr around 9-10 and the bike not wanting to pull past about 9-10k without leaning things out correct? This is a dyno problem only so far correct? Chris
YES and NO!
I can hear the Miss on Motor Only and it has lost about 10 Min to 15 HP Max HP on Motor
Then the Way it runs on SPray is TOTALLY Different from what it "WAS" doing.
Usually I have a slight lean mix of about 14 to 1 and then the A/F of about 12 to 1. I am using a Bypass Regulator to speed up the fuel. Then at the end of the run down to 11 then 10. But the Engine Pulls it CLEANLY. Now as soon as I hit the Button the Bike Bucks and Jumps just like it did after the Big BANG a few weeks back.
Understand that the engine sounds exactly like it did after the Explosion and it has "NEVER" run like this before EVER
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Made History @ Daytona and still one fast old man!!
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dougmeyer
Needs a job
moderated
Posts: 2713
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posted October 23, 2006 03:37 PM
Could be a broken inner if it's not "tapping". A small change in timing shouldn't cause "breaking up" or missing. Check your N2O plumbing and jets maybe something not tight and leaking.......
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shane661
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posted October 23, 2006 03:52 PM
 Edited By: shane661 on 23 Oct 2006 17:36
/edit
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GUNNER
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Posts: 5778
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posted October 23, 2006 04:18 PM
Sorry to say Vince but it looks as if you're about to take it back apart and check everything..
If it makes you feel better this spring after I reassembled my 10R motor and it was still on the stand. I was cleaning up all my tools and putting them away just after putting the valve cover on and wiping the motor completely down. I'm taking one of my best jeweled dial indicators off the stand to put it away when I noticed that it was missing a very small screw from the back. NOW I had never noticed it gone till now and guess where it had spent the last several hours of it's life. You guessed right if you said parked over the top of my motor while I degreed the cams in.. GUESS what I did next.. Well first I crawled all over the shop floor looking for that screw and next I completely took the 10R motor back apart looking for it inside. Sadly it never turned up anywhere. It's about a 2-56 screw and I don't know where or when it fell out. BUT! I do know it's not in the 10R motor. Had I NOT checked that motor completely and it had some stupid problem or ANY problem at all that stupid screw would have haunted me forever.
Vince shit happens to all of us from time to time and we miss or over look things. How we recover is what separates true professionals from the want a bees... YOU WILL find the problem.
I learned that day to always check everything including my tools before they enter the playing field. Had I looked at the indicator closely and notice it missing a screw before I used it I would have saved 2 days of my life and a lot of Tums. I was sick but I wasn't about to let such a small thing slow me down more than it already had done.
I do still strain the oil at every change just bcause that screw never turned up. Even though I checked the motor completely out. 
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VincentHill
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posted October 23, 2006 04:43 PM
quote:
Could be a broken inner if it's not "tapping". A small change in timing shouldn't cause "breaking up" or missing. Check your N2O plumbing and jets maybe something not tight and leaking.......
It also has this slight Miss on Motor Only.
I am going to check the Springs to see if I can "Feel" anything different and reassemble the top end.
#1 right now I am going to check the Stick Coils and have bought another set to verify!
#2 Swap the ECU
#3 Bypass the Timing Retard
#4 Brand New Plugs
Last check the PC3 because I am not sure ab out the Chicken or the Egg!
Did I do something Mechanical on a larger Dose of NOS or did something electrical cause the Back Fire from the large dose??
Thanks Dr. DM (I know better than to call YOU Mister!)
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Made History @ Daytona and still one fast old man!!
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01zx12r
Expert Class
Posts: 338
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posted October 23, 2006 05:53 PM
One more thing to try, a RUNNING compression test.
Remove schrader core from compression hose and START the engine. This might atleast pinpoint what cylinder and if a MECHANICAL problem exists. Another way is to duplicate the misfire and check with a temp. gun the exhaust temp at the header as close to the exhaust port on each cylinder. Hope this helps, Chris.
P.S. What is your plug gap?
P.S.S. Do you have access to a Lab Scope with a low amp clamp? call me if its easier, Chris 316-650-8189
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Lovett Racing/Pedigo Performance
8.40 @170
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VincentHill
Needs a life
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posted October 23, 2006 07:21 PM
I was using Surface Gap Plugs and usually I set the Plugs at about 0.032 (35 may get the flame blown out and 28 does not ignite enough fuel
LAB Scope with a Low Amp clamp?
Now you got me. I have a Bore Scope to see and my guess is something that could watch the SPark plugs with the "LOW Amp Clamp" because the High AMP would would be for the High Voltage Wires which we do not have??
The Temp Gun is a good idea but I do not have one (Only an EGT in #4 Cylinder and a Oxygen Sensor in #3 & 4 (2 into 1 Pipe)
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Made History @ Daytona and still one fast old man!!
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VincentHill
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posted October 23, 2006 07:23 PM
Forgot to add that theStick Coils were in SPecs but 2 read 11.65 and 2 read 11.50 Ohms on the one test and all read 1.1 Ohms on the other test
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Made History @ Daytona and still one fast old man!!
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Texas12R
Zone Head
Posts: 545
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posted October 24, 2006 04:50 AM
I RESERVE THE RIGHT TO BE WRONG !!!!!! I have had a couple of instances where the "wierd miss" was electrical, although these where automobiles. The only reason I thought it might be worth posting was that the first step was to perform the static tests...ie ohm, voltage supplied,but the thing that got me was in the operating mode...I couldnt check the output at high rpm, elevated temps and this was where the gremlin would show up. I had a coil that was fine at lower that 5000 rpm, but by 5500 it was begining to drop output. I was told that marginal plugs can cause higher coil load because that energy has to go somewhere and if the resistance gets too high it will
eventually cause the coil to fail
I had a resistor type wire that had burned the silicon/carbon core 3/4" up into the insulating jacket, since it was still a partial path the only time it miss fired was under high load rpm.I just thought I would say that the dynamics of this world have left me not knowing if I was winding my ass or scratching my watch... 
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GUNNER
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posted October 24, 2006 10:10 AM
quote:
I would say that the dynamics of this world have left me not knowing if I was winding my ass or scratching my watch...
Me to 
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01zx12r
Expert Class
Posts: 338
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posted October 24, 2006 07:05 PM
Vince, with a low amp probe and a lab scope you can see how the coil reacts and might find the miss that way. it can show you the ramping of the coil and how well the primary circuts are working...
Crazy things can cause a hidden miss. Every check resistance of a spark plug? You would be amazed on what you find. Chris
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Lovett Racing/Pedigo Performance
8.40 @170
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VincentHill
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posted October 25, 2006 05:05 AM
Thanks Chris, WHere and How muc for this Scope? Or only the Shops can afford?
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Made History @ Daytona and still one fast old man!!
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01zx12r
Expert Class
Posts: 338
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posted October 25, 2006 08:01 PM
A good graphing meter or Lab Scope will run a couple grand. Any auto repair shop or maybe even pawn shop might have something you can rent/buy? If I had your bike we could check it, to big to ship to you. Fluke makes a good handheld lab scope.
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Lovett Racing/Pedigo Performance
8.40 @170
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slug
Pro
Out in search of my mind...
Posts: 1433
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posted October 26, 2006 05:36 PM
let's see if i have the sequence right
1. running great
2. bump N2O just a bit and BAMMO it makes nasty noise and starts to misfire.
Findings: Slightly weird head gasket? or nothing really?
To cure the engine-only miss you lean mix slightly. But nothing cures it on the N2O?
I wouldn't think that a fuel delivery change would really cure an electrical problem. It's possible, but masking an electrical fault with fuel seems counter-intuitive. But just in case i would take a really close look at engine & chassis grounding. Just to be sure.
As far as other stuff, this is REALLY reaching out on a limb here....
Since you got the top end totally apart (except the intake valves) we are probably relatively safe to disregard that as a failure option.
Which leaves something on the bottom.....
Is it possible to have just slightly bent a rod (just a smidge)? Not where you notice it, but where the piston doesn't quite go full stroke or maybe has a weird angle where the pressure during higher-pressure combustion causes it to sorta act as a load for a short bit before reversing course? The engine wouldn't actually be misfiring, but it would NOT run smoothly with a single cylinder slightly underperforming the rest.
There's enough movement in the piston/rod/pin to allow a slight bend without locking up, so a slow turn won't make any noticable difference.
just tossing ideas out, something that big mechanically which has measurable and verifiable negative effect on the engine operation HAD to mess something up. Now to figure out what.
Heck, could it have slightly bent the crank for that matter? But that would to me seem like a vibration issue more than a misfiring issue.
Good luck finding the evil little gremlin.
   
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GUNNER
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posted October 26, 2006 07:37 PM
Hmmmmmm????? Something to think about for sure....
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