LOUD popping and 1/2 power

[FvnnyL3tt3r1ng]

I was riding along just fine last weekend when all of a sudden I got some stutter. Bike just started running on one cylinder all of a sudden. I crawled it home and did the following:

Changed plugs
Checked fuel flow in carbs (good, but the only thing I am a little wary on)
Checked float height (tad bit high on cyl 1 @ ~3mm but it was running like that fine for months) Adjusted tang to bring level back down
Opened up bowls to check floats for leaks (good)
Pushed 'slides' up and they fell back with suction (sealed diaphrams)

I am going to check for compression later today/tomorrow but wanted to hear you guys' input....

Shoot

[Sirref]

you checked the oil right? recent enough oil change and enough still in the engine. past that I'd say that you would have to open the engine up to check anything further.

[FvnnyL3tt3r1ng]

Originally Posted by Sirref

you checked the oil right? recent enough oil change and enough still in the engine. past that I'd say that you would have to open the engine up to check anything further.

Yeah the oil level is good and fairly new.

I wouldn't be surprised if my petcock was taking a dump or something but I'd like to run a compression test first to help eliminate variables.

[choneofakind]

Spark plug wires. Coils. CDI. Leaky plug threads in head. Funky gunk in one carb. Serious air leaks on one side. Idk.


How is it that you have so many engine problems? Still stunting?

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

Spark plug wires. Coils. CDI. Leaky plug threads in head. Funky gunk in one carb. Serious air leaks on one side. Idk.


How is it that you have so many engine problems? Still stunting?

I have been on the bike like 4 times since October so idk.....

[FvnnyL3tt3r1ng]

Forgot I could check spark against the engine side.....How quickly we forget things!!!!

Just a fyi: harbor freight's inline spark test tool doesn't fit our bikes so don't buy em unless you got some other vehicle to test them on.

Now on to drinking........

[FvnnyL3tt3r1ng]

Originally Posted by choneofakind

Still stunting?

25f42152498f11e3b45c12bc0078aa9b_8.jpg

[dcj13]

Originally Posted by FvnnyL3tt3r1ng

...harbor freight's inline spark test tool doesn't fit our bikes so don't buy em unless you got some other vehicle to test them on.

The HF spark tester is super handy for checking for spark on lawnmowers, weed eaters, chainsaws, and leaf blowers. Not so good for overhead cam engines with the spark plug down a deep hole.

[Motofool]

Originally Posted by FvnnyL3tt3r1ng

...........I am going to check for compression later today/tomorrow but wanted to hear you guys' input....

One of the plugs is intermittently failing to spark.
Most common cause is a bad connection or broken cable standing some vibration.

[FvnnyL3tt3r1ng]

Originally Posted by Motofool

One of the plugs is intermittently failing to spark.
Most common cause is a bad connection or broken cable standing some vibration.

Hmmmmm. Ok I wonder how long this has been going on. Are the wires easily found at bike shops?

[FvnnyL3tt3r1ng]

@Motofool

I owe you a drink. Bought an adjustable gap spark tester and it seems cylinder 2 coil is out (intermittent). Saved me a lot of time running compression test and what not. Looking for some coils online now.

[FvnnyL3tt3r1ng]

Anyone know what this seller is talking about when they refer to an eliminator?

http://www.ebay.com/itm/KAWASAKI-EX2...2e0183&vxp=mtr

[fast1075]

EX-250 Eliminator, the cruiser style Kawi 250. Most use the same coils.

[alex.s]

the eliminator is the eL-250. not eX.

[FvnnyL3tt3r1ng]

Ahhhh ok. I was wondering why I didn't see any 'eliminations.'

Question: Where is the ignitor on the bike? Since the red wires are common to both coils perhaps I should trace back the black wire which is from the ignitor to coil 2......

The black wire also runs to the tach....my digital gauge has been shutting off and on I wonder if the two are related

[alex.s]

Originally Posted by FvnnyL3tt3r1ng

Ahhhh ok. I was wondering why I didn't see any 'eliminations.'

Question: Where is the ignitor on the bike? Since the red wires are common to both coils perhaps I should trace back the black wire which is from the ignitor to coil 2......

The black wire also runs to the tach....my digital gauge has been shutting off and on I wonder if the two are related

it sounds like the problem is in your digital gauge shorting the pickup or something. if you disconnect the gauge does it still **** up? the ignitor is the CDI which is like, under the seat or something.

[FvnnyL3tt3r1ng]

Originally Posted by alex.s

it sounds like the problem is in your digital gauge shorting the pickup or something. if you disconnect the gauge does it still **** up? the ignitor is the CDI which is like, under the seat or something.

I haven't troubleshot anything with my gauge. I just set it up and rode.... Too busy riding to fix things

Will check it out tomorrow under sunlight.

[FvnnyL3tt3r1ng]

I've been seeing schematics where coil one shares a wire with the tach and other schematics showing coil 2 doing so..... I guess you have to look at your bike to figure out how they wired yours.....

[FvnnyL3tt3r1ng]

Couldn't help myself, disconnected gauge and problem persists. Hopefully it isn't the cdi......

[Motofool]

Originally Posted by FvnnyL3tt3r1ng

@Motofool

I owe you a drink. Bought an adjustable gap spark tester and it seems cylinder 2 coil is out (intermittent). Saved me a lot of time running compression test and what not. Looking for some coils online now.

In my experience, coils work properly or fail.
Failure is sometimes associated with heat, so when the coil gets hot, one circuit opens and it doesn't work until it cools down.

As the missing sparks are intermittent, it is possible that the coil is not the source of the problem.

Coils are simple transformers: one primary coil and one secondary coil to multiply voltage many times.

[FvnnyL3tt3r1ng]

Originally Posted by Motofool

In my experience, coils work properly or fail.
Failure is sometimes associated with heat, so when the coil gets hot, one circuit opens and it doesn't work until it cools down.

As the missing sparks are intermittent, it is possible that the coil is not the source of the problem.

Coils are simple transformers: one primary coil and one secondary coil to multiply voltage many times.

Hmmm. The problem did start to happen after the bike warmed up but now it is permanent...... We'll see what happens when I put in a different set of coils on Friday.

[dcj13]

Originally Posted by Motofool

In my experience, coils work properly or fail.
Failure is sometimes associated with heat, so when the coil gets hot, one circuit opens and it doesn't work until it cools down.

As the missing sparks are intermittent, it is possible that the coil is not the source of the problem.

Coils are simple transformers: one primary coil and one secondary coil to multiply voltage many times.

Other people experience intermittent failures on coils, especially when the coils get hot. Hond VT500FT Ascots are famous for coil failures (especially as the bikes/coils age).

[FvnnyL3tt3r1ng]

Ok, put spare coil in for cylinder 2 and problem persists. Tried starting the bike and I have to hold the starter for longer than usual with full choke just to get it going on 1/2 power. Here are videos of coil 1 and 2 for perspective:

Coil 2 (sparking better than before)
http://youtu.be/gnvJD1TB3L8

Coil 1
http://youtu.be/q9VL87aCRtM

Does this point to the CDI? Do those usually take a dump out of nowhere like mine seemed to have?

[FvnnyL3tt3r1ng]

Maybe I should replace coil 1 as well....

[FvnnyL3tt3r1ng]

Well as I originally suspected I have no compression in cyl1 and 120psi in cyl2 which is kinda low imo. I did use copper tan spray on the head gasket so maybe that decided it was time to go....

Time to pull the engine and get back to wrenching. New head gasket this time.

[quarterliter]

Get a buell blast, so you don't oil starve your engine. That is what is continuing to cause you problems with the 250. The buell has a dry sump.

[FvnnyL3tt3r1ng]

Can't believe I'm running into problems already.... I'm guessing a valve came out since there is 0 compression in cylinder one.... why oh why. I will be selling this bike after I restore it though.

[Whiskey]

Originally Posted by FvnnyL3tt3r1ng

Can't believe I'm running into problems already.... I'm guessing a valve came out since there is 0 compression in cylinder one.... why oh why. I will be selling this bike after I restore it though.

Just don't let the perspective buyer see ninjette

[FvnnyL3tt3r1ng]

Lol. Well I'd like to think I'm selling a decent bike I'd probably offer a helping hand with any issues down the road or something.

[FvnnyL3tt3r1ng]

Ok so I'm in the engine and doing the timing and the chain tension is varying as I rotate the shaft.... It locks after 1.5 revolutions or so both directions. There is nothing in between chain and gear... It goes from loose to tight.... ?????????

[FvnnyL3tt3r1ng]

Originally Posted by FvnnyL3tt3r1ng

Ok so I'm in the engine and doing the timing and the chain tension is varying as I rotate the shaft.... It locks after 1.5 revolutions or so both directions. There is nothing in between chain and gear... It goes from loose to tight.... ?????????

Ok now chain is out of equation, and still locks... Is there someway to dislodge whatever may between my gears? I put the engine upside down and spun the crank and same thing....

[FvnnyL3tt3r1ng]

Strange, I took the head and block off, spun the engine with the chain in my hand just fine over and over again......so I put everything back together and now the problem is back! WTF

The front sprocket/output shaft spins freely so I know it is in neutral.....

Maybe this is normal but when I crank the engine over by hand and stop something inside is still spinning...... Could it be the starter gear coming out or something? The engine was moved every which way......

The chain tension is constant now.......

Oh and I forgot to mention: there was no compression because one of the rockers came out and 3 nuts came off total! I retrieved 2 and when I opened up my oil screen I got a handful of metal so I am assuming it was all taken care of???????

I stuck a magnet through the piston openings in the case and underneath the clutch basket and nothing... No rattling or anything either.....

@Motofool @n4mwd @choneofakind @Sirref @dcj13 @Whiskey @quarterliter @alex.s who am I missing??

[n4mwd]

IF you still have that spare engine, now is the time to use it.

The thing about the coils is that they are sensitive to the polarity of the way they are hooked up to the wiring harness. Coils are what is called autotransformers.



Looking at the diagram you can see that the ground must be connected to the common section between the two coils (shown here connected to a switch). If its hooked up backwards, then the spark plug sparks through the extra primary winding. Although this would probably still work, it can damage the winding and produce weaker sparks. It can damage the primary because it was designed for 12V not 20KV.

You haven't really addressed the popping sound here. A failed coil will not really cause the bike to backfire. Backfires occur when the timing is wrong - either electrical or valves. Your CDI pickup sensor is working fine because if it wasn't, you'd not get any spark at all.

But like I said, if your valves are messed up, just pop in your spare engine.

[FvnnyL3tt3r1ng]

The popping sound was because of my bad timing because of a valve stuck open. I need help with this engine seizing now.

[n4mwd]

I'm still not sure why you always seem to have engine problems.

What kind of stunting are you doing? I don't think wheelies would be that harmful to the engine. Any chance dirt can get into the air intake or oil breather?

Honestly, I think you might like something like an enduro dirt bike better. They are lighter and can handle abuse better. And with the bigger ones, you can jump stuff with them.

[FvnnyL3tt3r1ng]

I have ridden this bike like 5 times since October. none of that has been anything other than normal street riding. Ive been working all day no breaks on this bike and all I'm asking is for help with my current issue so I can move forward with it tomorrow.

[n4mwd]

the only thing I can say is that if your rocker arms are broken then you'll have to rebuild your head. hopefully there's nothing else wrong such as of cracked piston.

so what I suggest is that you pull in head, replace everything that is bent or broken, and then check to make sure nothing is binding.

I can come by tomorrow afternoon if you still haven't made good progress.

[FvnnyL3tt3r1ng]

Originally Posted by n4mwd

the only thing I can say is that if your rocker arms are broken then you'll have to rebuild your head. hopefully there's nothing else wrong such as of cracked piston.

so what I suggest is that you pull in head, replace everything that is bent or broken, and then check to make sure nothing is binding.

I can come by tomorrow afternoon if you still haven't made good progress.

I've replaced the valve which I'm pretty sure was bent as well as three rockers since I have spares. I adjusted all but two of those rockers (because of the locking issue) so all I have to do when I figure out this problem is them.

This is so weird, I remember it occasionally happening in the past (on different engine) but corrected itself so I never thought about it deeper.

As far as that noise I was talking about, it was the starter spinning. I pulled the alternator cover to satisfy my curiosity and everything was normal. Of course I bent the coolant pipe there and I don't have a spare so I won't be able to ride until I get one shipped here.

I'm not exactly sure what caused this issue but I always have adjusted the rockers to the looser end of the tolerance so perhaps I went overboard and they self-destructed. That's why this time I'm using the next size feeler gauge down to make sure this doesn't happen again. I knew that bike wasn't putting out as much as it should and I think the looser rockers must have been the issue.

[n4mwd]

I hope I'm stating the obvious, but when you do your valves, you need to use metric feelers, not SAE. The nuts on the rockers should not come loose if they are torqued properly. In any event, check the dog ears on ALL of them to make sure they aren't cracked. You should also check to make sure that a valve strike didn't crack the bearing mounts that hold the cams.

So then put it all back together and recheck your compression.

Is there any way to bend your coolant pipe back together?

[FvnnyL3tt3r1ng]

Originally Posted by n4mwd

I hope I'm stating the obvious, but when you do your valves, you need to use metric feelers, not SAE. The nuts on the rockers should not come loose if they are torqued properly. In any event, check the dog ears on ALL of them to make sure they aren't cracked. You should also check to make sure that a valve strike didn't crack the bearing mounts that hold the cams.

So then put it all back together and recheck your compression.

Is there any way to bend your coolant pipe back together?

I do pay close attention to whether I'm using metric or standard, no harm in reminding someone though. My gauges have metric and SAE on them and so does the tolerance I wrote on the paper I go off of.

I don't know why they came lose either. I torque them to the point where if I did go further it would probably break them....

Problem with checking the compression is that the engine is seizing in one spot when I move it one way, and another spot when I go the opposite way. Like I said I turned the engine over by pulling on the chain many times over but after I put the cams and everything back into place it went back to seizing again........

I'm baffled.

No the pipe ripped. I could probably attach a rubber hose in its place as a temp fix though.