Plug Pic

[KRMit]

I'm running a single 35PWK with DEL needle in 4th clip from top, 52 pilot, 175 main. I through some new BR8ES plugs in yesterday and rode through maybe 1 tank of fuel. Both plugs look like the one below. The porcelain and strap are completely black. I mostly rode around in low gears all day. If I lean the needle one clip I get a lot of hesitation at 1/4 throttle. What do I do?

 

[frocashmoney24]

you need to get her in the highest gear possible at wot for a few seconds, it could totally change how that plug looks, do it ona diffrent set

[KRMit]

One of those plugs was so fouled after riding it wouldn't even fire so something has to be off. If I let the bike warmup on a new set of plugs for about 30 minutes then do a WOT check, won't they still come out black? They won't go from black back to white will they?

[bigboybanshee]

I don't think they would go from black to white but I would assume that if you correct the "richness" that the plugs would lighten up. I'd try leaning out your pilot jet a size and see what happens

[mrmatt]

You're still trying to get the jetting right? That sucks. I hadn't seen a post from you in a while so I assumed you got it figured out.

Can you see a color change on the ground strap? If so, compare it to the pictures in the Jetting FAQ. I found out that BR8ES were too cold for my Banshee. So I switched to BR7ES. Quite a few people told me not to do this and that it would cause detonation. But the color change on the ground strap is in the middle of the bend with the 7's. I don't know why my motor needs the hotter plugs, but once I figured this out, it was much easier to read the plugs for carburetor adjustment. I will caution you, as many people cautioned me, you should make sure that your engine needs the 7s before you really run it hard with them.

After normal riding, my plugs looked exactly like yours before I switched to 7s and got the jetting worked out.

 

I suggust putting the needle in the middle clip and leaving it alone until you get the pilot and main jets right. I spent countless hours adjusting my needle and air screws to eliminate a 1/4 throttle hesitation, when the real problem was that my pilot jets were too small. I found out that there are too many variables to work with and I kept masking the real problem. I refused to change the pilot jet, since most other people that use PT mids run a stock pilot. Once I went up a couple if sizes on the pilot and put the needle and air screws at there stock setting, the 1/4 throttle hesitation went away. So maybe you need to do the same, go with a larger pilot.

The best way that I found to adjust the pilot and air screw is to cruise down the road or in an open area in 4th gear. To maintain a constant speed, I only need to apply a little bit of throttle. If the pilot/air screw was rich, then it would pull smoothly, but sputter and sound like it was loading up. If the pilot jet/air screw was too lean, then it would run rough and buck as if only seem to make power on every few revolutions of the motor. But when the pilot jet/air screw was right it ran smooth and clean.

 

As far as main jet. My banshee was running lean on 540s, but then I changed the intake/filter setup and now jetting is perfect with 390s. Are you happy with your main jet, or are you still having trouble with it?

Edited September 13, 2004 by mrmatt

[KRMit]

Well, I went from 175 main all the way to 220 with little difference in performance. I was doing my plug checks by slapping a new plug in and ripping up the road WOT. I didn't realize that isn't enough time and the plug's going to stay white regardless. So I came back down to 175 and rode on about 1/2 a tank and the plugs were chocolate colored. It's been running pretty strong except for the last two weekends. Weekend before last it would bog real bad when I pinned the throttle from about 1/4 (sometimes). I went from 58 pilot to 52 pilot and lowered the needle to the middle clip and it would hesitate real bad at 1/4. So I went back to second richest clip position, put new plugs in and it rode pretty good all day (with the exception of smoking pretty bad when I first cranked it up). Now I have 2 fouled plugs.

 

I thought I was pretty close on the jetting but apparently not. I'm obviously too rich on some circuit but I don't know if it's pilot or main or both. Does the needle size make a big difference?

[Banchetta]

Lower your pilot. Try a 45 pilot and go from there.

[Nightrider]

That plug looks wet/black,which obviously means its wayy rich somewhere.I don't know if it woud be the pilot as much as the needle or main.If your cruising around at any more than 1/8 throttle your getting into the needle.

 

You said it ran great for the last 2 weeks,which might point to atmopheric conditions

 

Temps will play a big part during this time of the season.My shee runs great on a 70-75 degree day with no humidity,but in 85-90 degrees with 80% humidity,it lugs a bit in the lower rpms and produces a rich plug reading.

 

The only happy medium I found was adding an extra 1" vent to the airbox and plugging it.When the temps and humidity rise,I'll pop out the plug and let the engine take in a bit more air.Its works good for me cause I'm not into rejetting for constant weather changes.Sure,I could just tuff it out on those hot/muggy days,but shee needs to be running her best at all times.

 

Keep track of weather conditions as you experiment with jetting,its always good to test under the same conditions or close as possible when you tryin to dial it in.

[mrmatt]

I think that you are wasting your time with the pilot jet and needle until you get the main jet figured out. Your problem sounds exactly like mine. I know that our engine set ups are very different, but the symptoms that you are having are the same as I had. I think it would be benefitial if we could talk. Send me a PM with your phone number and I'll give you a call. I tried at least a dozen different things to fix mine. We can talk about what I tried and if any of them may work for you.

Matt

[Banchetta]

If he just rebuilt the shee and hasn't gotten it wide open yet, then the mains have nothing to do w/ his jetting problems yet. If your shee is running clean at half throttle, then the needles aren't too rich, if they were, then the shee would spit and sputter like the choke is on. If your fouling plugs, then it only leaves one circuit left. Thats why I suggest the pilot. Besides, my stroker w/ pwks don't even run that size pilot.

[KRMit]

I guess I'll drop it to a 48 pilot and see what happens. I don't think I need to go a notch leaner on the clip cause when I tried that it hesitated a lot and backfired into the airbox (if that makes any sense). I've read that the needle diameter has a big affect on 1/4 throttle too. A friend of mine has more needles I might try. The most frustrating part is that I can't ride around my house so I have to wait until the weekends to really try anything.

 

Thanks for the offer mrmatt, I might take ya up on it.

[Banchetta]

I guess I'll drop it to a 48 pilot and see what happens. I don't think I need to go a notch leaner on the clip cause when I tried that it hesitated a lot and backfired into the airbox (if that makes any sense). I've read that the needle diameter has a big affect on 1/4 throttle too. A friend of mine has more needles I might try. The most frustrating part is that I can't ride around my house so I have to wait until the weekends to really try anything.

 

Thanks for the offer mrmatt, I might take ya up on it.

That makes perfect sense. The leaner clip position will cause the powerband to hesitate and sometimes backfire. A really rich needle will cause it to spit and sputter like the choke on a car. A lean pilot will cause the shee to start hard when cold and hesitate before powerband. A rich pilot will make the shee start easy when cold, but hard when warm. It'll also make your shee sluggish before powerband and sometimes have to rev the motor to clean it out. A rich pilot will also make the plugs foul. For needle diameters: It narrows down the needle clip positions. It has the same effect as the clip position, but only at 1/4 throttle where the clip position effects 1/4-3/4 throttle...hope this helps

[KRMit]

UPDATE

 

I'm down to a 48 pilot still running the 175 main. The needle is in the second richest clip and if I go to middle clip it hesitates real bad.

 

I finally got around to doing a WOT test today and the plug I pulled actually looked pretty good. It's about the color of a Hershey bar. So that rules out the main jet. I've been running on some B8ES plugs for a couple weekends and they seem fine.

 

My current problem is kinda weird. For the first hour or two of riding it runs great and pulls strong. Then all the sudden for no apparent reason it'll start gurgling when I give it 3/4 to full throttle. It'll clear up after a few minutes but it's real annoying. It seems like the left cylinder is cutting out. I guess it could be something electrical but I dunno what.

 

How do I jet the pilot? My Shee smokes a LOT when its first cranked after a couple days and smokes a little at idle, but hardly smokes at all while riding.

 

Thanks for the help guys! It feels good to do my first proper plug check.

 

[sredish]

More or less, you'll just jet it for ease of starting and idling. The rule of thumb I use to begin with is if you can start it cold without the choke, then it's too rich, if you need the choke to start it when it's hot, then your lean. You should have to use the choke to cold start and not need it when it's warm. Pilot jetting is somewhat trial and error. Smoking isn't necessarily something to go by. Mine smokes like a hippie when I first start it, after 6 or 7 minutes it'll clear for the most part. If it never ever clears at idle, then you may want to investigate. You can let it idle for like 5 minutes and then kill it and check the plug. If it's loaded with oil and looks like it's starting to buildup you might lean it out one size and then recheck.

 

Hope that helps.

[sredish]

You might try a DEK needle instead of a DEL. That will richen up just off idle to 1/4 throttle. Then you could lean your pilot a touch and maybe eliminate your smoking while maintaining your 1/8th and up response.

 

Just a thought.