Plug read help & questions

[Rickrod3]

http://s910.photobucket.com/albums/a...t=DSCF2905.jpg

What do you guys think?

I'm having 2 issues:

on #3 the spark plug gap gets smaller. I'm using Mikes green coils so I'm gapping them @ .035 and when I pulled the plug the gap was considerably smaller.
Running Champion plugs 3415 which my auto parts guy said was the replacement for stock plugs.

I checked the dimensions and they are the same as the stock NGK plug which # escapes me at the moment.

Issue #2:
from around 3K have a real flat spot. Real pain some times letting the clutch out. some times its not so bad.

BTW running stock jets, stock air box and 4 into 2 slash cuts I've been tring to Identify. Closest I've come is Mac 4 into 2 they have no baffle.
So I was going to go up one pilot size and 2 main jet sizes.

Synced carbs with carb sticks a few times. I'm pretty comfortable that they are in sync.

above 3500 RPM takes off like the space shuttle.
Never took it past 90mph at 6k but don't really plan to and on a thirty year old bike that sat for 24 years that I got running myself 90 is plenty fast
seemed like it would go more tho.

Tia
Rick

[dbeardslee]

If it is burning the electrodes off, you need to widen the gap to .040. I run the iridium plugs with the green coils, and those I leave gapped to .035. Iridium is very hard and has high heat resistance, so they work really well with the hot green coils. Your plugs do not look bad, (maybe a little lean) but it takes time for them to fully color. You can probably reduce the sooty ring by going 1mm higher (when carbs are upside down) on your floats. How are your carbs jetted?

[Rasputin]

I am not so sure you have the correct plugs in there. When I go to

http://www.sparkplugs.com/results_ap...D=16337&mfid=2

the 3415 is not listed as a choice. The 3415 also does not cross reference to the correct NGK plug. When I look at applications for the 3415 it does not show the XS1100 either. The only way that the gap can possibly get smaller is if something is hitting the ground electrode. I would try a different set of plugs to see if there is a physical difference. Just my 2 cents.

[XS1100 Newbie]

First thing to do is get rid of those Chinese Champion plugs, and get NGK back in there. Some plugs just don't work well in certain applications. You said the gap was getting smaller!!!. Only a couple of ways for that to happen. If you bumped it going in, or you have something hitting it. The reach is to long, and very bad for the pistons. The right plug, the right gap, then check it, but get NGK plugs. I quit using Champion back in 1979, and don't use it on anything except our PT Cruiser, and that is only because the electronics are set up to use Chanpions. Even in racing, i only used NGK, and the lawn mower, and, etc etc etc.

[MrOzz]

First thing to do is get rid of those Chinese Champion plugs, and get NGK back in there. Some plugs just don't work well in certain applications. You said the gap was getting smaller!!!. Only a couple of ways for that to happen. If you bumped it going in, or you have something hitting it. The reach is to long, and very bad for the pistons. The right plug, the right gap, then check it, but get NGK plugs. I quit using Champion back in 1979, and don't use it on anything except our PT Cruiser, and that is only because the electronics are set up to use Chanpions. Even in racing, i only used NGK, and the lawn mower, and, etc etc etc.

Same here. I use the NGKs for everything, except in my PT where I also use only Champions.

[Rickrod3]

Okay new plugs

With mikes Coils can I run the stock NGK's ?

Back to jetting.
Am running 137.5 Mains and 42.5 pilots
I was planning to go to 145 mains with 45 on the pilots

Want to address that flat spot @ 3K

[randy]

Rick,

145 is a BIG jump from 137.5. Do you have an aftermarket exhaust or intake mods, like pods? If not, you may be able to correct the flat spot by relocating the needle clips or adjusting the idle screws. See below my setup for my 79F. Keep in mind, the stock cams don't 'wake up' till 3000-3500 rpm.

[dbeardslee]

Yes, you can run the stock NGKs (BP6ES) with the green mikes coils. Gap should be between .035 and .040.

[Rickrod3]

My bad

Rick,

145 is a BIG jump from 137.5. Do you have an aftermarket exhaust or intake mods, like pods? If not, you may be able to correct the flat spot by relocating the needle clips or adjusting the idle screws. See below my setup for my 79F. Keep in mind, the stock cams don't 'wake up' till 3000-3500 rpm.

I was planning to go to 142.5

I'm running pipes that I'm not sure what they are.
They look like Mac 4 into 2 with a slash cut or turn outs.
They have no baffles.

[Rickrod3]

Rick,

145 is a BIG jump from 137.5. Do you have an aftermarket exhaust or intake mods, like pods? If not, you may be able to correct the flat spot by relocating the needle clips or adjusting the idle screws. See below my setup for my 79F. Keep in mind, the stock cams don't 'wake up' till 3000-3500 rpm.

What pilots are you running?
I'm running the 42.5's with the pilot screws 3 and 1/2 turns out and some times taking off I have to double clutch to keep from stalling.
It gets alittle dangerous merging in from a stop the bike doen't want to go till I get over 3k.

[randy]

I kept the stock pilots, whatever number they are? How about your floats? have you tried adjusting them for a richer mixture. I have mine set 1mm richer (higher in the bowl)

[dbeardslee]

If you are running without baffles you may find it hard to tune. Motor needs a little back pressure. JAT

[WMarshy]

Hey Rick,

Nice looking bike you have. I second everyone else, NGK are my choice in plugs. Here is a great video on the proper way to read your plugs. It took me a few times of watching it to fully understand everything... I have nearly the same problem with my bike but not as bad, I have stock air box with K&N filter,a 4-1 Jardine exhaust, and 42.5 and 137.5 jetting. Its just flat on bottom end and stumbles at about 3000-3500 in 55 degF weather and below. No problems with stalling/idling though. For me, its worse on colder days and near 35 degrees F it leans out and will pop a little and doesnt want to idle. I have to run it with the enricher partially engaged on days like that, you can tell its just too lean on the low speed circuit. Once its into the 60's there is no more stumble and not as flat on low end. I plan on changing to 142.5 mains and giving them a try. If that dont clear things up I will try a 45 pilot too... Are you using your stock airbox and filter with those slash cut Mac's?

[jwhughes3]

What is the cylinder order?

1-2-3-4 left to right sitting on it?

4-3-2-1 right to left sitting on it?

In the second case I have sooty plugs on 1 and 3 and if I remember these fire off same coil, right? So maybe I have a weak coil?

Seems to run fine - just poor mpg.

John in San Antonio

[bikerphil]

1-2-3-4 left to right sitting on it?

That is correct. 1&4 fire on the same coil and 2&3 on the other.