Maxim-X spark plug caps

So my recent acquisition of an XJ700XN has left me with quite a bit of work to do. Valve clearance checks are imminent, carbs are coming off tonight for cleaning (thank you, Schmuckaholic, for a great guide with pictures AND humor), oil change, bleed out old brake fluid, etc.

I've been trying to figure out why the bike starts and idles nicely, but dies when I let the clutch out and try to get rolling. I have to rev it up and feather the clutch. The PO seemed to think this was normal.

#2 and #3 plugs are black and wet. #3 might even have been a little oily (compression check in my future?) I checked the coils yesterday and while taking the measurement (with plug caps on) #3 cap came off in my hand. Nasty green corrosion everywhere. Surely the carbs aren't pristine, but I'm guessing this might have been causing poor ignition in #2/#3.

Anyway, I FUBAR'd the plug cap for #3 trying to clean it. I'm too embarrassed to go into the details. Has anyone had good experience with an aftermarket boot on a Maxim-X? The Maxim-X website doesn't have the spark plug cap service web page ready yet; it's still under construction. I've been looking at NGK XB05FP or VB05FP trying to figure out if one of these will work. Chacal seems to have an original for $42. I'm not sure the big orange rubber boots at the bottom of the OEM caps are replicated on the NGK aftermarket caps. I put a picture of the current boot in my gallery next to a ruler. The NGK XB05FP has a 70 mm dimension to the bend, but I can't figure out if this is would include the large orange boot on the original, or if that is given up with an aftermarket unit.

Chaz

PS - I may only be in "1st gear" but if they counted by posts read I think I might be a red liner.

 

Ooh, just found this post where WeAreZilla posted what appears to be the solution; the orange boot comes off and can transfer to a NGK aftermarket part?

 

Yup the orange boot comes off with a twist and pull. no problems. You do know that the stock plug caps come mostly apart into 4,5 or 6 peices right? If you happen to replace them all I do need a few spare parts just in case. I would pay shipping. WHen you take them apart there are some small peices that lets jsut say one or two have gotten away before hehe.. You can and should at least trim the wire back 3/8" to get a good firm grip when installing the new ones.

 

Yes, the pieces look mostly good except for the spring. I have a spring, a little brass disc, ceramic (resistor?) rod, and a the assembly that grips the plug. If there's more than that, it's on the floor somewhere.

 

nope them and the plastic is it. The other thing you need to check out and I can't remember what years they did what. one year the X had a resistor cap, and the other they ran the resistor plugs but not a resistor cap. I want to say the 85's had the resistor in the cap and in 86' they went to just using the resistor plugs. You want to get a replacement with the same resistance and make sure you don't double up by having both the caps and plugs with resistors.

 

The '85 Maxim X has the resistor caps.

 

Careful cleaning the ceramic rod...actually it's probably too late.
I believe most of the conductivity was on the outside and it you tried to sand it or buff it, you probably killed it.

Measure the resistance once it's assembled. I believe it is supposed to be 5K Ohm
I had three that wouldn't even conduct enough to measure.
You can replace the resistor core with a piece of copper...4mm IIRC (taking away the resistance)
Clean the ends of the spring, and I had to add some dilectric cleaner to the cap and then take a drill and a drywall screw to spin the spring against the top inside of the cap to clean it.
If you change to non-resistor caps, I suggest going with resistor plugs.

BUT, you are also pretty much guaranteed that the carbs will have to come off too.

Double check the caps, drop in a set of fresh plugs and take it for a ride.
Pull the plugs again and see what they "say"...you have probably read all about plug chops and Black is rich...white is BAD (lean)...and you want a nice tan.
My experience with my Xs has been that tweaking the mixture almost always means adjusting the sync too.

 

Aha, I did *not* sand or buff the ceramic rod. Thanks for the tip. Actually I killed the spring, but that's a different story. I'll check the 5k ohms on the others. The coils measured 21k through the resistor caps, which may be a good sign.