Spark plug caps?

[Crasher]

Anyone had there caps wear out?

My 05 800 is running really irratic at WOT, otherwise runs perfect. RPM jumps up and down like it is missing spark every other stroke. Plugs look good, no fouling.

New pistons and rings this year. It started doing this last spring.
Changed plugs (twice) cleaned clutches, cleaned RAVEs, checked intake boots.

I cleaned the caps with carb cleaner an lots of black carbon washed out. The caps seemed kind of loose so I squished them with pliers but it still acts like it misses at WOT. Getting worse each time I go out.

 

[eazyduzit509]

From what I was told yes, they can go bad. Sled mechanic told me that the caps have resistors in them that can wear out or go out. Actually, last year I got 2 new caps for my 99 670 because I was told they went out and was having problems, so I switched em out an there great now. Get some new ones, I think mine were around $10 for both.

 

[Tackbtch]

Yuppers they go bad , usually in the back country, carry two spares all the time. Dino

 

[DRD]

Does it happen only at WOT?

 

[Crasher]

Does it happen only at WOT?

Yep, otherwise runs perfect.

 

[DRD]

I'm just going through this on my 05 but I think I fixed it. Go over to Doo Talk and search "Zoomies" or "Pipe Surge". Joey also has a pretty good write up on his website, MXZrevzone or something like that.

For a quick test lower your clickers to 1 and see if it makes it better.

At any rate I did all the normal stuff like changing plug caps, plugs, checking reeds, Raves you name it, checked, but none made it run better. In the end it looks like a new spring tower cap, fresh spring and a little more weight in the pins and it's finally pulling clean.

 

[Crasher]

Gonna try the caps and go from there. Don't think it is a spring problem, it was new last fall. Clutch seems to be pulling real well. It holds 7800 on clicker 2 until it starts the missing thing. Just starts missing erratically at wot.


Thanks for the input. I'll let you guys know the fix as soon as the CAPs I ordered get here.

 

[DRD]

Mine would run good everywhere until WOT, let off a bit and it would clear up.
If it's "Pipe Surge" you will hear it in the exhaust note, or have someone listen. It will literally sound like " Rah, Rah,Rah". Do the reading I mentioned on Joey's site and on DooTalk while you're waiting for the plug caps.

It's not a spring problem, it's how the motor is being loaded and building heat in the pipe.

 

[McStevoKLX]

Can you order just caps or do you have to get the cap & wire combo?

 

[eazyduzit509]

yes

I got mine seperate from the wires. Like I said, bout 5 bucks each...

 

[MountainPowder]

Some car parts places have them in stock, the caps just screw into the wire, easy fix. I carry two spares in my backpack.

 

[Crasher]

Well, it is not the caps. Pulls like a frieght train untill you give it WOT. Then Raw, Raw, Raw. Up and down at 7800-8000 Clickers on 1.

Should I add some pin weight and see what happens or reinstall stock primary spring. I am using 160-290. Confused, this setup worked perfect for 2 years and now I am getting this Raw, Raw, Raw from the engine.

 

[Boondocker_153]

Try This

I fought the same problem for several weeks and tried all the stuff you are trying thinking that is was electrical. I found, after a real close inspection, that the clear hoses going to the dpm had very, very small holes in them that caused the problem. I replaced the hoses and it has ran like new ever since. I hope this helps, if not good luck.