Topic: Plug reading - Need advice

[joeyvans]

pictures 1-3 are awfully lean! Picture 4 is getting close to where i'd want to be.

Cal - I went out for a couple longer rides later yesterday... 65-ish miles each..... riding the same.  I didn't take pics of the plugs after the ride, but I will do that tonight.  All airscrews are currently at 1.5 out.  Any thoughts on where I should go from here?  Do you think there is anything to my exhaust theory?

Thanks for the response, man!

[flybox1]

pictures 1-3 are awfully lean! Picture 4 is getting close to where i'd want to be.

Cal - I went out for a couple longer rides later yesterday... 65-ish miles each..... riding the same.  I didn't take pics of the plugs after the ride, but I will do that tonight.  All airscrews are currently at 1.5 out.  Any thoughts on where I should go from here?  Do you think there is anything to my exhaust theory?

Thanks for the response, man!

pictures of plugs after a ride does nothing and gives you no information.
its just an accumulation of deposits for all the throttle positions you were in, and says nothing about any particular throttle position.
do proper plug chops please.
read below to understand why we do plug chops in a particular sequence. 
please ignore the particulars.  concentrate on the process.

Id say no on the colder plug. Stick with D7EA's...here's why
Because of the jet overlap in any given throttle position, Sam needs to concentrate on getting  WOT Main jet mixture perfect. First.
If you work on pilot jet or mixture screw settings first, you cant make carb adjustments for needle pos and mains without messing everything else up.

For example, lets say you have your pilot/mixture screw circuit perfect....nice tan plugs, but you are still lean at WOT....well, an increase of main jet size will and does INCREASE fuel levels at every throttle position below WOT.
You've just fooked up your perfect idle/pilot mixture by going richer on the mains.  
So Sam, do a vacuum sync with your current settings, and go do a WOT chop first.  Get your main jets (90/92/95/100) right first, before you move on.

2/3 throttle position chop is next, for needle clip location. lowering the needle clip a slot(towards the sharp end) makes it richer.  raising it makes it leaner. get it right before you move on.

Next, 1/4 throttle position for pilot jet size.  Get it right before you move on.

Idle chop for your mixture screw.  Set all screws to factory setting +1/2 turn(IIWM), and do another vacuum sync while you are letting deposits form on your plugs.  You should be running really well about now, and able to dial in vacuum near perfect.
As you tune this circuit, treat each carb separately.  They can and will all have slightly different screw settings.

[Deltarider]

I find it hard to believe with stock airbag and jets you're that lean? You're not at some crazy high elevation are you?

Wouldn't that high elevation enrich the mixture?
Are you sure the advancer works well?
BTW, personally I can't read new plugs but that's me.

[joeyvans]

I think Flybox encouraged you to go to 1.75 on your screws already, and I would too. I find it hard to believe with stock airbag and jets you're that lean? You're not at some crazy high elevation are you?

Regarding the low RPM stumble: horse hockey that its normal! Its a pure indication of poor carburetion and more evidence you're too lean. There will be moments when you have to hold that rev range in 1st or 2nd and the bike should definitely not stumble.

Your exhaust: its a thought about the imbalanced back pressure causing the disparity. But for that to be true, only #4 pipe is good? If pipes other than #4 are good, than that shoots that theory.

Before you swap pilots, I'd ask you to verify with clear tube method, the fuel level in the carbs. I would suspect that to be your culprit over incorrect jets. Or, your timing is whacked?

Fargo, ND elevation = 904 feet above sea level 

Air screws:  The pictures above are from a 1.75 out setting.  Sorry, I turned them in a 1/4 turn after my 1st 65 mile ride yesterday.  They are currently at 1.5 and I haven't taken pictures of the plugs at that setting. 

Float levels:  I'm glad you mentioned clear tube, because I didn't do that after I rebuilt the carbs... just set all floats to 22mm.  I have an extra drain plug on the way so I can do the clear tube easier.  Will do this as soon as I receive & rig up the tool.  Can you clarify for me?  If the level is higher than the 4mm below where the bowl mates the body... I need to go greater than 22mm float height, correct?

Timing:  Last I checked with a timing light, 1-4 & 2-3 are spot on at idle & advance.  I did snip off a coil on each advancer spring a couple months ago because the springs were a little worn.  However, since I think my tach is off... maybe the timing needs to be adjusted accordingly as well.  I think I will pick up a sensitive tach and get this checked & readjusted if necessary at 1000 rpm.

Fly:  Thanks for the tip on plug chops.  It was a stupid thought thinking I could just check deposits periodically after rides since I am running stock per the Honda service manual.  Wish we had hills around here so I could do a proper WOT chop.  Any advice on a WOT plug chop on flat ground would be much appreciated! 

Overall, she runs really strong, but I am just concerned about seizing the motor with the current readings. 

[flybox1]

look back at your 'around town' plug color in your earlier post.
the bottom one, #4....that's what i'm looking for on all plugs in all plug chops.
if those plugs were done at 1.75 turns mixture screws.  leave it there.  1.5 will further lean out the idle circuit
its better for your engine to run on the rich side, than lean.  as-is, you are too lean. 

load the engine and you will be fine. 4th gear WOT. uphill, headwind, etc...do the best you can.

[joeyvans]

look back at your 'around town' plug color in your earlier post.
the bottom one, #4....that's what i'm looking for on all plugs in all plug chops.
if those plugs were done at 1.75 turns mixture screws.  leave it there.  1.5 will further lean out the idle circuit
its better for your engine to run on the rich side, than lean.  as-is, you are too lean. 

load the engine and you will be fine. 4th gear WOT. uphill, headwind, etc...do the best you can.

Thanks Fly... I have definitely been trying to achieve a richer status. I was thinking turning in my mixture screw (087a carbs - screw on airbox side of the carb) would richen the mixture, which is why I tried 1.5. Am I wrong about that?

[flybox1]

look back at your 'around town' plug color in your earlier post.
the bottom one, #4....that's what i'm looking for on all plugs in all plug chops.
if those plugs were done at 1.75 turns mixture screws.  leave it there.  1.5 will further lean out the idle circuit
its better for your engine to run on the rich side, than lean.  as-is, you are too lean. 

load the engine and you will be fine. 4th gear WOT. uphill, headwind, etc...do the best you can.

Thanks Fly... I have definitely been trying to achieve a richer status. I was thinking turning in my mixture screw (087a carbs - screw on airbox side of the carb) would richen the mixture, which is why I tried 1.5. Am I wrong about that?

My error. yes, you are correct.  in to richen. 
(two other threads dealing w PD carbs in my head  )

[joeyvans]

New plan of action:

1) hook up sensitive tach, so I can get an accurate 1000 rpm idle. Then recheck timing and adjust if necessary.

2) clear tube method as soon as my plug & brass tube stock arrives.

3) ditch the exhaust (unfortunately, because I love the look) for the MotoGP Werks 4-1 that is sitting in a box eagerly awaiting install.

4) up mains to 105's and needle clips to middle position as a good starting point.

5) plug chops

6) hopefully set it and forget it. Sh%t... I probably owe Ronco some coin for using that slogan.

[flybox1]

[joeyvans]

Haha! Memes are fun.

[joeyvans]

Your exhaust: its a thought about the imbalanced back pressure causing the disparity. But for that to be true, only #4 pipe is good? If pipes other than #4 are good, than that shoots that theory.

Actually, #4 seems to have the most holes in it, the worst being where the header meets the muffler. All other pipes (1-3) have some exhaust exiting where it is supposed to. When I hold my hand up to #4... I feel nothing.

Anyways, No reason to hash this out. Hopefully float heights are the culprit for leanness on 1-3.

Thanks again, guys! We'll get this one figured out sooner or later.

[joeyvans]

Well, over the course of the past 2 weekends, I clear tubed all carbs. They were all set at 22mm, now one is at 25, one at 24, and two at 23. While carbs were off, I popped in 105 mains and moved my needles to middle position. New Honda fuel line without inline filters and reinstalled carbs. Put new in tank strainer on petcock, refilled tank.

This past weekend I fitted a MotoGP Werks 4-1. Tightened and cleaned with acetone before firing. HOLY #$%*E... what a difference the new exhaust has made! Zero stumble off idle, strong through all throttle ranges. Still might be a tad lean with some decel popping, but will adjust mixture to get some darker readings. Aside from floats being off before, I believe I found the issue with #4.... exhaust leak at the head. Found carbon around the collars from the original exhaust. Why didn't I check the collars before? Oh well. She runs like a top now! 

[flybox1]

Nice work JV! 

[joeyvans]

Thanks Fly.... I appreciate your and everybody else's guidance on the matter! Best MC forum on the net!

[Redline it]

Stumbling...If it's an older bike with original factory parts, it can at any time have some stumbling. Was it sold like that? Probably not. Can it be like it was when new? Possibly but more than likely not. Try to remember when you were 13 or 15 yrs old. It'd be bad ass to get back there, and maybe you can, for a short time. The one range I shoot for is the Wide Open range to be on the money. Most of these bikes are 6 speed high revving engines, if I have stumbling...I start from first gear doing 10,000 rpm going out the driveway!

[joeyvans]

if I have stumbling...I start from first gear doing 10,000 rpm going out the driveway!

That explains your forum handle quite well!   

[joeyvans]

Well, much to Redline's chagrin... I am going to try to resurrect this a bit because I don't want to stop tuning until there is zero hesitation across all throttle ranges.  Noticed stumbing from 1/4 to nearly 1/2 (probably 3/8) throttle last night in 1st gear. But, man.... when it hits about 3/8 throttle the thing rips like hell!  1/4 to 3/8 in 1st gear is the only time I notice any stumbling, as I like to wind it up... so it isn't a HUGE deal, but I want as perfect performance as I can get.  With this symptom, am I correct in saying that I have a rich condition in low RPM's?  Here are my stats again:

MotoGP Werks 4-1
UNI replacement foam filter in stock airbox with all necessary hoses attached
087a carbs, clean as a whistle
Fuel levels verified to 4mm below bowl mating surface
105 mains
Needle clip in 3rd position (stock is 4th)
Air screw currently at 1.5

Last night, I played with the air screw going from 1.75 to 1.5 to 1.25 to see if there was any noticeable difference in the stumble.

1) It seems to me, there is less stumble at 1.75, but popping on decel is considerably more.
2) Starting at 1.5, the decal popping gets better, but seems like more stumble.
3) Decel popping is nearly gone at 1.25, but stumble is even more noticeable.

Side note:  I need to re-check my timing.  It was spot-on prior to the last carb removal, but I have neglected to check it since then, and I have definitely messed with my idle screw since, so I may be idling at a different RPM than where the last timing was set (bad tach).  And yes... I have performed a vac sync since the carbs were reinstalled with the 105's and clip change.

My question is.... should I be moving the needle clip back down to 4th position?  Then, play with the mixture screw?  Or, is it just a matter of miniscule mixture adjustments.

Thanks in advance, ya'll!

Kyle

[mrfish2]

Have you done any plug chops yet? Just based off of what you have said thus far I would say to move the needle clips back to the 4th position, but do a 1/2 throttle plug chop first and report back.

[joeyvans]

Have you done any plug chops yet? Just based off of what you have said thus far I would say to move the needle clips back to the 4th position, but do a 1/2 throttle plug chop first and report back.

Just WOT and was good there. Yeah, I'll work my way down the range. Do I skip 3/4? Thanks Fish!

[flybox1]

if stock needle position is 4th from the top, why did you go to 3rd?  going up a slot leans out the bike.
go to back to stock needle position, ride, and report back.

[joeyvans]

if stock needle position is 4th from the top, why did you go to 3rd?  going up a slot leans out the bike.
go to back to stock needle position, ride, and report back.

That decision was based on other reports I have read from other members. However, I went back last night to verify and found that those reports were probably premature to final settings. Oh well... I'll switch clip position tonight while carbs are on the bike. Not taking those SOB's off again if I don't have to. Thanks again, guys! Will report my findings.

[harisuluv]

I saw that your float settings were quite varied, which is fine as you clear tubed them (unless the geomoetry is altered so that they hit or now restrict).  Very common on the boards lately to have this issue:

http://forums.sohc4.net/index.php/topic,149845.msg1709910.html#new

[joeyvans]

I saw that your float settings were quite varied, which is fine as you clear tubed them (unless the geomoetry is altered so that they hit or now restrict).  Very common on the boards lately to have this issue:

http://forums.sohc4.net/index.php/topic,149845.msg1709910.html#new

Good call, James! I did make sure both sides of each float were identical height, but did not verify that the tangs were parallel. That will be on my "to do" list. Thanks for mentioning it, as I have not seen this thread or considered it.

[harisuluv]

Yeah there are two tangs, the float height, and the float drop.  Then the whole brass part needs to be straight.  A lot of floats I get are just a mess.  They have to be "dressed" or straightened out for awhile until the float height setting will even really be applicable.  As was pointed out earlier by calj the setting assumes OEM parts, floats that are untweaked, etc.  That's where clear tube comes in to verify if needed.

In that thread I linked though, the member might not have been able to clear tube though because the float was so mangled that it was actually physically hitting the carb body, any changes made to the tang would not change anything. 

[joeyvans]

Still haven't done all my plug chops, but 2/3 throttle is next, followed by 1/4 and idle.  Now I have an additional concern....

With regular riding, I have noticed quite a bit of carbon buildup on the #4 plug.  All other plugs are showing consistent deposits.  I have no idea if this could be decent theory or not..... but I believe I have more carbon buildup in the #4 head, due to the exhaust leak at the collar that I discovered when I removed the original exhaust.  Could this be an accurate theory?  More air introduced to that cylinder head over time could have caused more carbon buildup... which is why I am seeing deposits on the #4 plug? 

If so, should I consider decoking that cylinder head?

Kyle