MISSING ON LOAD

[ohiojack]

Well I may have messed up. I was getting on the bike running the rpm/speed up to around 90 mph, all at once it started missing bad under load in lower gears and the bike shudders at high speed roll ons. At normal cruising speed the miss is gone. One of my spark plug caps is broken on the bottom almost up to where it plugs onto the plug. The bike has new plugs, air and fuel filter last year. The carbs have been gone through and it was finally getting around 48-50 mpg. Any ideas??? ohiojack

[Tonyvdb]

One of my spark plug caps is broken on the bottom almost up to where it plugs onto the plug.

That's the problem right there, you will need to replace that cap with a new one as the spark is jumping out of the cap at the break.
They are really available at NAPA or other parts places. They just unscrew from the wire.

[ohiojack]

I was wondering if the cap was the problem, thanks for the response. ohiojack ps Are you going to the the rally in June??

[Lucasind]

....I remember our DEARLY departed AVA member, and former webmaster (debron,Ron Riggs) had the same thing happen to his XII on a cross country trip, I think you could find his post from a few years back if you did a search,.....turned out a plug cap and/or wire replacement made his XII ride like a new bike again ! likely that is what you have here , good it showed up now ,before heading to the rally !giving you plenty of time to correct this very minor issue

[Mr Jensee]

I agree it's the plug cap but also make sure your fuel line around the filter and pump is not in anyway kinked that might starve the engine of fuel at high speeds.

[the2knights]

I am jumping on the band wagon as well. I put new caps on last year. When you do so, make sure you check the boots and the end of the wires, I took about 1/4" off each of mine just to make sure the connection was real good. I found a set of NGK caps for sale cheaper than ordering OEM last year.

[triton28]

These are the least expensive plug caps I have found: http://z1parts.net/ngk-sd05f-spark-plug-cover" onclick="window.open(this.href);return false;

Dave

[ohiojack]

Thanks for the answers, I will get new caps. Also I noticed the cruise now does not work. Hopefully the two issues are related. ohiojack

[ohiojack]

Well I started checking things, first I put in a new gas filter and checked the lines. Test rode the bike and the miss/shudder was still there. I replaced the bad plug cap, the miss was still there. I finally pulled all the plugs they all look the same, no evidence of missing, they all look clean. I'm beginning to wonder if the fuel pump is giving out or if I have problem with the cdi/box. I'm going to double check the air filter to make sure I don't have a mouse nest. I'm still looking. The bike is starting to make me wonder if I will find the problem!! ohiojack

[Tonyvdb]

Are you 100% sure that the spark plug is not cracked? If you put too much side pressure on them as you remove or put them in you can crack the ceramic sleeve and the spark can jump out of that crack (I know this because I've done it) and it's really hard to see the crack.

[voyager55]

Try some Sea foam in your gas, might have some junk in the carbs

[ohiojack]

I checked with my local mechanic at the kawasaki dealership and he said to check the mains, needle and diaphram . The needle and diaphram's checked out, no holes, tares or problems. I pulled the bowls and checked the mains. One main jet had a piece of plastic/ junk stuck in it. I had to use compressed air to get it out. Got the bike back together but haven,t had time to ride it yet.. hopefully it's fixed.

[Lucasind]

Hey Jack , I just noticed that you gave me ring on my cell, Sounds like you found the problem,.....Tony

[ohiojack]

Thats ok Tony, you we're probably out riding. I hope this problem is gone. ohiojack