Spark Plug Cleaners

[johnc]

Hello All,

I was wondering if anyone had tried out any spark plug cleaners?

Well, I can't post links....kind of dumb. If you search for 32860-2VGA on the harbor freight site, you'll see what I'm talking about.

I have one, and they seem to come out really clean, but I'm also experiencing a really annoying problem with my bike that has run like a champ for the last 7 years or so. A 1994 KDX250. I've been running BR8ES and BR8EVX plugs in it.

The thing will run fine, get me about a half-mile from the house, and then bog out. I've chopped a 1/4" off the spark plug wire to make sure I'm getting good current, and cleaned the carb out and checked the float / air screw, etc.....twice.

Like I said, I haven't touched the carb/jetting since I've owned this bike, and I'm going to put a NEW plug in it tomorrow, but I'm basically wondering if other people have tried these cleaners, and found that they are junk or work well, or what.

Thanks!

John C.

 

[G. Gearloose]

Rejet then cease dinking with plugs.
One errant leftover piece of silicon carbide media left in the plug will tear up the jug. Not worth it.

 

[johnc]

So, "rebuild the top end, now." tear up the jug? Or "it'll stick to the carbon that's already in there, and if you only put one or two plugs in there for no more than 6 hours of riding, it shouldn't matter much" tear up the jug?

Thanks!!!

JC

 

[76GMC1500]

A plug fouling problem that starts suddenly in a bikes life is not likely jetting because the jetting doesn't change on its own. It is more likely a bad right side crankcase seal. Debris from the transmission deposits on the porcelain insulator for the center electrode and causes the plug to short circuit, the arc follows the insulator to ground instead of crossing at the gap. You'll have to split cases to do the seals on your Kawasaki. There is a chance your main bearings are shot as well so you should check them carfully.

 

[johnc]

wow....seems like an extreme scenario.

What other symptoms would you see in this case? Seems like you would also be losing oil out of the tranny? If deposits from the tranny are making it into the combustion chamber, I would assume a loss of tranny oil as well, no?

Thanks!

JC

 

[johnc]

Alright, so I got in another 60 miles this weekend at White Rock, AR.

The first 30 mile lap went off without a hitch. Took a rest for about 20 mins, then started on the second lap.

5 mins into the second lap, the bike bogged out again.

Changed the plug, dropped the needle one clip, and finished the next 30 mile lap with no issues.

Took the plug out today, and it's pretty black, and seems a bit wet still, with a little grime around the bottom ring.

The two plugs I ran yesterday were brand new BR8ES.

I recently moved out here from AZ, and the change in elevation is about 1000ft lower. Never changed the jetting in the move.

So, what gives? Need to rejet, or am I looking at this seal problem? Is there any other way to diagnose the seal issue other than taking it all apart?

Thanks for the advice!!

JC

 

[flyingfuzzball]

if you moved and then your probs started then you probably need to rejet.

 

[76GMC1500]

Does your bike consume transmission oil between changes?

 

[johnc]

Ok, so I finally got around to looking into this a bit more.

I pulled the jets on the carb, and found that I had a 42 pilot and 158 main.

This bike has a pro-circuit pipe, and I removed the snorkel from the airbox.

The main seems really big from what I've read on the carb tuning page.

This is a 1994 KDX 250.

I'm also draining the tranny oil right now. I didn't warm the bike up first, but I'll let it go overnight, and see if I get close to .8 liters.

Would love to hear comments on the jetting. I'm thinking I'll leave the pilot where it is, and start stepping down the main.

Thanks!

John C.

 

[johnc]

Alrighty then.

The oil was fine. I pulled out 800ml, just what I had put in.

I did some more research on the KDX 250 carb jetting that had worked well for other people, and found that a 38 pilot and 158 main seemed to work well.

I just put in the 38 pilot and left the 158 main that was already there. I just realized that I forgot to check the needle. Being that I'm the second owner, and I met the first owner and know how he rode the thing, I'm betting it's still the stock needle.

I set the airscrew at 1.5 turns out, put the needle at the second clip from the top, and WOW, what a difference this seems to make. Much more responsive, and actually took the front wheel off the ground involuntarily in 2nd gear. MUCH DIFFERENT than the 42/158. Seems like it may still be running a little rich, but my main question is this.

It's obviously running leaner than it was, I left the 158 main jet in. Is there any chance that changing the pilot to the 38 will cause me to run too lean at any point in the power curve? If so, what are the symptoms? I really don't think that it's too lean, I just want to make sure I recognize it if it's happening.

Thanks!

John C.

 

[John Harris]

If it doesn't rev up when idling and you are not shutting it down from high speed to no throttle like on the street then you do not have too small a pilot. In general, 2 stroke dirt bikes do not sieze at low speed. The pilot needs to be small enough that the air screw is operative and so the bike does not have to lag and clean out as it comes on the main jet. I probably did not say this well, but I hope I helped. Sounds like you are close! John