Carby My C Clip does not agree with me

[Waxxumus]

I guess I'll jump in here, yeah, you should start somewhere between .024 and .028 they say.

Ive heard anywhere between .024 and .036

Is there any reputable source which has the gap specs for the chinabike motor?

 

[Slogger]

I've got mine at .030 because I can get away with it. I have an HD lightning with the separate coil, I guess it makes more spark juice.
The .024 to .028 is just the opinion of lots of motorbike guys. I read a lot.
Nothing chiseled in stone. People get good results gapping them that way.
They say the spark is more reliable at low RPM, like when your trying to start the engine. It makes sense, less gap is easier to jump.

 

[butre]

I gap at .035 generally, but different motors want different gaps

 

[Waxxumus]

Seeee what I mean.
I have had no problem whatsoever in starting with a .038 gap.
But.
I just got 4 Iridium tipped sparkplugs for the price of 1.
I think there was a mixup @ the factory.
Hot dang I just saved 24 bucks.

 

[Waxxumus]

So I have recieved some iridium tipped NGK sparkplugs.
And I notice.
They are about a half a millimeter - one millimeter or so longer.
Is this cause for concern at all?

 

[Waxxumus]

They are the exact you specified.
BPR7HIX

 

[crassius]

gap may differ depending on whether you have 250ohm, 350ohm, or 480ohm mag coil

 

[KCvale]

So I have recieved some iridium tipped NGK sparkplugs.
And I notice.
They are about a half a millimeter - one millimeter or so longer.
Is this cause for concern at all?

Only if you have messed with your head, like milling it.
That little extra length gives you a little extra compression to go with the much larger spark you will be getting ;-}

Don't short yourself with a crummy connection between the Mag and CDI, those 'quick connect' couplers are junk.
I don't even **** with stock wiring, I run black very flexible double insulated 16g speaker wire from the mag to cut down leads on the CDI and solder.

Note this wire is red and white not black and blue.
I use red for blue (hot), white is the black ground

For old style mags with the useless white wire I just cut that off.
If the Mag ground is good you can ground your CDI ground wire anywhere.

For the new Mags the bottom lug is ground.
No soldered tab, which means it's need a wire to ground.
I solder my white ground wire to the lug, but you have to make sure you don't remove the mags ground wire.
This the ground your spark plug needs to work.

Run your new wire however it looks best up to the CDI and solder up it and kill button to the CDI.

Cap it off with a little hobby box or something and you have a pretty bulletproof ignition system, you can even put a keylock switch in there..

What gets many people is wire colors.
The ONLY important things is the Top lug of a Mag goes to the Blue wire on the CDI, and some ground to the Black CDI wire.

You actually don't even need 2 wires from the Mag.
A single fat hot wire from the blue mag to the blue CDI wire and then just run the CDI's black wire to a frame ground and it will work, the rub is using the frame as you ignition ground, paint and such tends to add resistance to the circuit so I run a pair of wire just to be sure.

Just tips, not 'must do's' or anything, just that little extra attention to details that not only make it look better, but make it a better more reliable machine.

 

[butre]

I've got mine at .030 because I can get away with it. I have an HD lightning with the separate coil, I guess it makes more spark juice.
The .024 to .028 is just the opinion of lots of motorbike guys. I read a lot.
Nothing chiseled in stone. People get good results gapping them that way.
They say the spark is more reliable at low RPM, like when your trying to start the engine. It makes sense, less gap is easier to jump.

I just changed my gap from .035 to .025 and can confirm easier starts but I developed significant 4 stroking at high rpm. I'm not sure whether I actually lost top speed or if my intentionally rich jetting is just coming out more. I'll test it out shortly.

actually, I just cracked my intake manifold, I'll be out of commission for the rest of the day now. it's a hairline crack so it still runs and doesn't seem to leak but hairline cracks turn into broken in half rather quickly. I changing the jetting won't do me any good today.

 

[Slogger]

Edit: I didn't see your edit when I wrote this.

I don't know if it's a spark issue, but maybe try .028/.030. Your slightly smaller spark may be letting you down on top.
Trial and error, that's my method.

My engine has always been a little too rich, only here lately I finally got it leaned out. No more baked valvoline on the piston crown and plug.
If I told you my main jet size, I'd spend an hour typing because it would set off a dogfight over jetting, it's that odd. My air filter is a genyoowine Dellorto SHA part, steel mesh that is very restrictive. The vacuum is so high behind it I had to go small on the jet. Very small.
Each one really is unique, with all these carb/manifold/pipe/head and porting choices out there trial and error is about all we have.