Topic: Need advice reading these spark plugs? Pics Included.

[elquenada]

So I pulled my plugs yesterday and took pics.  This just a preliminary test and I was not riding when I pulled the plugs.  I plan to get fresh plugs in there and do a better test this week.
I just got my bike back together the other day after pulling the carbs for cleaning.  I set the air screws where the PO had left them (approx 3 turns out) and then I synched them up. (ignition timing and valve clearences were set previously).  The bike runs well  but the bikes feels powerless in 1rst and 2nd gear.  I think the mixture is a too rich in cylinder #1 but Im not sure about the other plugs.  Here are the pics what do you think? 

Spark #1



Spark #2



Spark#3



Spark#4

[w1sa]

Were those plugs clean before you put them back the last time, (before the photo)?.
They sure indicate a good degree of all over rich (esp #4,could also be oil fouled), but the real (plug) picture of mixture strength depends on how the engine was being run prior to last shutdown. That's why a plug chop is so useful.

Looking at those plugs and considering you have the air screw out to 3, it could be a few things. The first things i'd look at next are the spark strength (with clean/new plugs), and possible exhaust restriction...........

[grumpy]

All look rich but #1 is awful - is that oil on there? It looks shiny in the photo but it's hard to tell.

[elquenada]

thanks for the responses.  These plugs were cleaned up a little when I did a compression test weeks ago but since then I have not touched them and the pics were taken yesterday. The littlle oil spot seen in pic#1 is because I sat the plug down for a moment on the engine case and it picked up a little oil; it wasn't on the plug before that.

Im gonna get some new plugs today if I can and adjust the mixture screws to make a slightly leaner mix and then take a look at what I get.

[BVCB650]

1 is definitely too rich. The others.......probably not as the color you are looking for is anything from tan to light grey. But, they certainly aren't the cleanest burning plugs I've ever seen.

[w1sa]

Sooty plugs are only an indication of poorly ignited fuel, not necessarily mixture setting.

I'd still check the ignition and be satisfied there is no exhaust restriction before leaning the mixture.

[elquenada]

ok what part of the iginition would you test?  the coils, the spark?  The PO installed a Dyna S electronic ignition.  I check the timing and its seems good.  Should I just check the resistance of the coils or should I check spark or both?

[BVCB650]

Yes, you could do all that, or do like I do and swap know good parts. Since #1 is sooty, maybe swap a good plug wire for it and see if things improve. Same thing for the #1-4 coil. No need to go anyfarther than that since #4 is better than #1. Look at the spark. Is it fat and blue? Is one plug better spark that the others. Switch them too.

[Duke McDukiedook]

Both. Check the wires and boots also to make sure they are not leaky/bad connections.

Did you check your valve clearances also?

[honda750k]

The actual SPARK is the biggest thing.   if you dont have a fat blue spark its not going to ignite the mixture well and you get what you've seen.

[elquenada]

i did check the valve clearences about a week ago.  I will check out the spark next chance I get out of curiosity but truthfully it is a moot point because my engine gaskets are leaking oil and im about to pull the whole thing apart.  I just got my vesrah gasket kit and Im ready to go.

[TwoTired]

I set the air screws where the PO had left them (approx 3 turns out) and then I synched them up. (ignition timing and valve clearences were set previously).  The bike runs well  but the bikes feels powerless in 1rst and 2nd gear.  I think the mixture is a too rich in cylinder #1 but Im not sure about the other plugs.  Here are the pics what do you think? 

3 turns out on the air screws is too much.  I would expect, when you get things ironed out, that you will have poor throttle response with that setting.
Are you using the stock air filter and exhaust?
Is your air cleaner clean as new?  Or, is it choking the engine? 

Check spark plug deposits with new plugs not old used ones and certainly AFTER the carb sync.

[BVCB650]

I set the air screws where the PO had left them (approx 3 turns out) and then I synched them up. (ignition timing and valve clearences were set previously).  The bike runs well  but the bikes feels powerless in 1rst and 2nd gear.  I think the mixture is a too rich in cylinder #1 but Im not sure about the other plugs.  Here are the pics what do you think?  

3 turns out on the air screws is too much.  I would expect, when you get things ironed out, that you will have poor throttle response with that setting.
Are you using the stock air filter and exhaust?
Is your air cleaner clean as new?  Or, is it choking the engine?  

Check spark plug deposits with new plugs not old used ones and certainly AFTER the carb sync.

His jetting may not be stock. I am at 2.5 turns out at 8000' in elevation. Light grey plugs, snappy acceleration. It all depends on how you have it set up. These are my pilot screws, not air screws which I have none.

[TwoTired]

The 650 has accelerator pump carbs (Or CVs) the 550 does not.

It is true he hasn't told us enough about his bike, though.  Leaving us all to make wild guesses, or assume it is in stock configuration.

[elquenada]

sorry heres more info.  Bike is pretty much all stock.  75 cb 550 (check out the avatar)  I have a dyna s electronic ignition installed with stock coils.  I am running the stock air filter (which looks pretty new to me) and my jets are stock as well.

[TwoTired]

Honda maintains the stock paper air filters must be replaced every 6000 miles or six months.  I have made them work for a year, but then they soot up the plugs, as they get more restrictive with time.

This was too costly for me.  So, I changed to a UNI NU-4055 foam filter that can be cleaned and reused.  The first one lasted 15 years before the foam began to crumble.

Anyway, I don't think you can tell the flow characteristics of the stock paper filters by appearance.  I theorize that the humidity softens the paper fibers and the suction they are subjected to make them collapse and become more restrictive with time and use.  Adding restriction is similar to applying partial choke.

If you don't know how old your air filter is, I suggest you replace it.  If it doesn't help your problem, you can always put it on the shelf to reuse when the replacement gets too restrictive to use.

[elquenada]

thanks for the tip.  i think i'll check out that uni filter cause it seems like it is a worthwhile investment.