My Stick Coil Mod Doesn't work! Any Ideas?

[Neosophist]

Ok so I went to test the idle voltage on the battery today and the Junction box is 'ticking'

Sounds like the relays buggard! :O

I've got a shed load of spares so I changed it with another that doesn't seem to 'tick' i'll see if that makes a difference.. it has a chance

Anyone else had a ticking junction box?

[Neosophist]

Still doesn't idle :/

Voltage is slightly lower with junction boxes that don't tick.

Will try a new reg/rec today then possibly some non-iridum plugs

[Neosophist]

Ok... it's not the stick coils

It's something else

I've tried one by one (still made no difference)

-Original coils
-Different junction box (this one doesn't tick so i've left it on)
-Different Reg/Rec
-Iridium plugs / Standard EK Plugs (Both burning lovely Tan color)
-Removed vaccum-gauge points and blanked off with bolt & washer to eliminate possibility of air-leak


I've uploaded some videos

http://www.youtube.com/watch?v=gSDGnVGyo_Q

http://www.youtube.com/watch?v=t-9NQwYsDbk

You can see it bogging down at idle, it often cuts out completely (it just didn't in these videos)

I do have a different CDI somewhere but I can't find it at the moment.

It could be carb related? Someone suggested possibility of a burnt valve?

Any suggestions would be really appreciated right now, it's ready for the bin!

[RedexRobB]

thought about the fuel pump?

[Mori Man]

thought about the fuel pump?

Good thought Rob , also try the relay !

[Neosophist]

I've got a spare fuel pump.. i'll try this next The one on it does pump though..

I took the tank off yesterday and it ran (bogging down / cutting out for 5 minutes or so on just the fuel in the pipes / carb) Still.. best to rule it out!

Thanks for the input guys. I really appreciate it!

thought about the fuel pump?

Good thought Rob , also try the relay !

Fuel pump relay? I've got a spare one too

[zimm]

could be a dwell issue with the coil's in combination with the stock ignition ..

the stock ignition uses quite a long "dwell" (evidenced by the ignitech software which defaults to "excitation = long" when setup for a zxr400 with stock coils) perhaps the dwell is excessive for the CBR coil sticks and is causing them to overheat when left idling..

at higher rpm it's less of an issue as the dwell is limited by the fact its time to spark again ..

I'm no expert with this stuff, but i recall TK400 going into detail on this in an old thread somewhere .. essentially coils have to be matched to the ignition,.. too little dwell and you have a weak spark at high rpm, too much and the coils overheat and cause a missfire.. for this reason, he suggested (having done the homework) using zx6r C1h coils as they "should" be compatible.. which is what i went with for mine... which i havent fitted yet.

[zimm]

err .. stuff

I actually have some of the zx6 ones waiting for my engine. They fit nice. The advantage is not actually the voltage. Its to do with dwell time and heat. If you run them on waste spark, there is little difference. If you run them sequentialy then as the coil only has to fire half as much it has a larger available dwell time up high rpm's. As at high rpm the available window for dwell is less that optimal. It is a great conversion , but to take best advantage it is best to run sequentially. I am working on a sequencer to alloy this on the 400. As for these if you just need to make sure the dwell is not to long at low revs as they will over heat. and that the dwell is long enough up high. this can be checked on the CRO. Mine are mitsubishi units. If they are the same I will test them for you on the ignition test rig and give you the data results. you may wish to direct some air over them to help cool them just incase they are a little high on dwell.........the reason dwell is a problem is that an inductor (coil) is the inverse principle of a capacitor. therefore the current increases exponentially and at ful charge it just keeps flowing untill turned off. hence to long a dwell time will overheat them. if this is the case you can add a series high watt resistor of the correct value. But this increases the required dwell time up high. Anyway enough rambling I will check for you. As those coils are expensive and I would hate to see them burn out. nice mod anyway..

cheers

regards TK400

[Neosophist]

could be a dwell issue with the coil's in combination with the stock ignition ..

the stock ignition uses quite a long "dwell" (evidenced by the ignitech software which defaults to "excitation = long" when setup for a zxr400 with stock coils) perhaps the dwell is excessive for the CBR coil sticks and is causing them to overheat when left idling..

at higher rpm it's less of an issue as the dwell is limited by the fact its time to spark again ..

I'm no expert with this stuff, but i recall TK400 going into detail on this in an old thread somewhere .. essentially coils have to be matched to the ignition,.. too little dwell and you have a weak spark at high rpm, too much and the coils overheat and cause a missfire.. for this reason, he suggested (having done the homework) using zx6r C1h coils as they "should" be compatible.. which is what i went with for mine... which i havent fitted yet.

Ok cool that makes sense to me!

I've put the standard ZXR coils back on the bike at the moment and it's still turd :'(

[zimm]

Ok cool that makes sense to me!

ah ha !

I've put the standard ZXR coils back on the bike at the moment and it's still turd :'(

ahh well ..

[Neosophist]

lol yep, right pita this bike.

I still think it's vaccumn / carb related

Will crack it

[Mori Man]

Stretch the diaphrams on the carb's and see if they have a hole in them anywhere - another cause for tick over issues to eliminate.

Your going to know your bike inside out by the end of this

[Neosophist]

I checked them when I cleaned the carbs.. there not holed.

Replaced the vaccum hoses that blank off the carb vaccum take-off ports today as per another memebers recommendations.

Still no better.

Tried all manor of pilot screw settings.. 1-5/8's / 2.0 / 2.5 and no difference really, still stuttering.

Petrol pump and relay are fine and working as they should.

Going to get a new set of carbs, only thing I havn't tried.

10mm adapter for compression tester is on order as I can't find mine :smt013

*fingers crossed it'll work soon*

I already know most of it backwards *sigh*

[RedexRobB]

What about spark plugs?

[Neosophist]

Tried new standard ones and new iridum ones, both the same.

It's got to be something daft now.

Will be compression testing it and trying some new carbs when I get some.

Tried pretty much everything else now!