Need help with finding non-resisted plug caps

So I've been having misfire issues again lately. Got worse over 2 weeks.

I think my bike really wants to retire.... keep having misfire issues.

I spent the long (and sunny) weekend rebuilding the damn carbs as the misfire was intermittent until the 2 days leading up to the weekend..... missed out on a road trip.....

After all this crap, only to find out my carbs were fine. So are my ignition coils and everything else.

It's my plug caps. on cylinder 4, so the short one.
The rest of them read around 5kohm. But that one reads something like 20kohm........

And since I'm in canada and can't get the non-resisted spark plugs locally anyways, I think it's time to switch my caps over to non-resisted caps and get some resisted plugs!

Does anyone have any sort of part number? or which the car that would have the cap that would fit??


And I read about removing the resistors in caps 2 and 3, then replacing it with a brass rod...... Does it have to be brass? Or could I just find a bolt that would fit, hack off the head, and shove her in there?


Thanks!

 

Try a car parts store for one cap or get a whole set for about 30$
Could get some at a place that does tune ups, they throw good ones away all the time

 

MikesXS used to sell them to Canadians for 3.65$ each, try this link and scroll down until you see the plug caps:

http://www.xs650direct.com/products-27.html

 

But I'd have to find a cap that screws onto the wire rite? Most car wires are one unit with the cap. So how does that work?

I went to the parts store and they can't think of anything so I'm gonna hit the junk yard now. If there's a specific car that you guys know would work then let me know

 

Plenty of old brit bikes have the type of cap tyou seek.

 

The caps MikesXS sells are the screw-on-the-wire type. They will fit your XJ wires, no problem there. I don't get your point...

 

I wanted some asap..... didn't wanna wait for shipping. Anyways, i got them from a local motorsports shop.

But turns out that's not what caused the misfire.............


time for more diagnosing........ arg......

 

what sort of misfire? An abrupt stutter or a soft breakdown? At all rev ranges?

 

Did you check the resistance of the cap while it was attached to the plug wire, or removed from the plug wire?

 

Ignition coil, new plug caps, and plugs are all good

Misifiring while under load between idle and 1/3 throttle. Idles fine, over 1/3 throttle running fine.

Feels like it's running on 3 cylinders when its misfiring

The symptoms point to a pilot circuit, but i JUST did a FULL rebuild, tune, and carb sync.

I did also do a pull and shut the motor off as it was misfiring to read the plugs. All is looking well........ WTF!?!?!
Have I just gone insane? or am I lean and my plugs some permanently tanned? I'm relatively new to the world of reading plugs, I've always driven fuel injected cars..... But from my understanding, the plugs change colours spontaneously.... rite?

 

You can only get a good "chop" reading on brand new plugs (as in-: warm up engine, stop, fit new plugs, run up to speed & chop)

Also, I find that resistor type plugs are absolute cack, they seen to foul and otherwise break down way too easily compared to non-resistor plugs. Maybe I just have bad luck but I'll never use NGK resistor plugs again :?

Sounds to me (part load misfire) like a sticking carb piston, did you pass the clunk test OK? And were the rubbers fine, no pinholes? (easily missed & easy to double check with carbs on bike) Or maybe blockage in emulsion tube, you removed/cleaned those though right?

 

Are the coil bodies cracked?

 

Oh........ And if I've cleaned the plugs with a wire brush and degreaser to get them white before i do the chop reading, would i still get an accurate reading?

If i AM running into issues with air fuel ratio then i could only be running too lean as my plugs are tanned properly but probably from before....... i'll adjust idle needle to run 'em richer and see if that helps...

The carb boots look good to me. And What's the clunk test? I know the part that's supposed to slide up and down is sliding smoothly. They're also rather stable when the bike is running. are they supposed to vibrate or be smooth?


And the emulsion tube is the one for the main jet with those tiny holes in 'em rite? I cleaned them good. I took everything off and soaked all metal parts in pinesol for 2 days and then boiled for an hour.

 

oh and of course I also used needles and wire brushes to make sure everything is clean before installation.



And the ignition coils are fine. I've dealt with them before. JB welded the entire mother f**ker, then undercoated it. I do ride in the rain so I wanted to double wrap those b**ches to make sure I ain't gon run into trouble on the road. Resistance through them also checked out fine.

 

Despite all your carb work, I think you've got a float height issue. Start from cold, take short ride and feel the headers. Obviously if one is cooler you've narrowed it down.

 

nope, not float height. I set those.

Turns out..... somehow..... the pilot jet fell off....... don't ask me how but it did

I was being careful not to over tighten those frigile brass or copper jets and i guess it wasn't tight enough. I've damaged one trying to take it off before and thats why i didn't tighten them too much.

Anyways, it's all in there nice and snug, did another carb sync. all is running good

Thanks guys

 

:idea: 8)

 

Glad you're sorted, I've had that happen before on another bike probably due to the same reasoning of not wanting to damage the jet. It's surprising how much force those jets can take with a well fitted screwdriver, I deliberately snapped one in a scrap carb one time & I had to really try (the emulsion tube cracked at the small drillings eventually), you wouldn't be able to do it normally refitting jets unless you're a gorilla with no fine motor control lol