do these symptoms suggest I need a valve adjustment? Edit: or bent valve?

Started by Rudemouthsky, October 18, 2013, 02:29:01 PM

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Speeddog

Hard to tell from pics, those are good pics though.

Those plugs are very new.
Tough to tell due to that as well.
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koko64

Im looking at them from a long way away, so I need your opinion guys. ;D
2015 Scrambler 800

jjjrules

I'm seeing what looks like a grey pubic hair hanging off the end of the plug in the third photo!

Seriously tho Koko - I think your diagnosis is spot on - looks like burned oil on the end of the porcelain to me. There does appear to be a grey "velvety" texture to the bottom part under the oil glaze.

Howie

Some oil some glaze.  IMO, the glaze probably from partial misfire under load.  Like Speeddog said, hard to tell for sure in spite of the excellent photos.  To get a glaze like that I think the ignition has to be pretty good.  Was that "grey pubic hair" on the plug when it came out.

I would want to see what a set of new plugs does first before breaking the bank. 

Rudemouthsky

#49
The grey pubic hair is from carrying the plug in my (apparently grey pube filled) pocket.

That was a brand new plug, taken out after about a 5 mile blast down the hwy and a 6 mile return trip through stop and go traffic. Around 10 miles total on the plug. Then it sat in my car's ashtray for about a week and my pocket for a few minutes.

I know it's pretty much moot at this point, was just curious what the experts thought of it, if anything. This is what happens, the bike runs great for about ten miles or so, then this.
"while there is a lower class, I am in it, and while there is a criminal element, I am of it, and while there is a soul in prison, I am not free." -Debs

koko64

I would like to see the carbs tuned and jetted correctly. You know what Im going to say about that.  A too big slow jet can foul plugs and cause misfiring on the slow part of the journey. Too lean main jets can give the other misfiring, backfiring , flames out pipe symptoms at the faster part of your journey. How you are riding when the symptoms occur matters. A carb tuner for that job. Strange jetting high and low for pods could give you symptoms like you have. You can get strange plug patterns.  Globs of oil "washed" off the bore, etc can happen. An experienced carb guy with the bike in his hands will figure this out. If you can get the bike to someone like that. If not I can give you a base setting and you would have to buy some jets (inluding the 165s Brad suggested).

A question, how easily does the bike start? Need the accelerator pump to prime it?

There may be a case of an ignition component fail after riding awhile when it heats up (on the end of the journey?). I wonder what a test of ignition pickups, etc would reveal?.
Howie could walk you through that. The coils are strong though, as howie pointed out. Did the shop do that stuff?

As howie pointed out no expensive headwork until correct jetting is established and an ignition fault is ruled out.
2015 Scrambler 800

Howie

Quote from: koko64 on November 18, 2013, 10:25:09 AM
I would like to see the carbs tuned and jetted correctly. You know what Im going to say about that.  A too big slow jet can foul plugs and cause misfiring on the slow part of the journey. Too lean main jets can give the other misfiring, backfiring , flames out pipe symptoms at the faster part of your journey. How you are riding when the symptoms occur matters. A carb tuner for that job. Strange jetting high and low for pods could give you symptoms like you have. You can get strange plug patterns.  Globs of oil "washed" off the bore, etc can happen. An experienced carb guy with the bike in his hands will figure this out. If you can get the bike to someone like that. If not I can give you a base setting and you would have to buy some jets (inluding the 165s Brad suggested).

A question, how easily does the bike start? Need the accelerator pump to prime it?

There may be a case of an ignition component fail after riding awhile when it heats up (on the end of the journey?). I wonder what a test of ignition pickups, etc would reveal?.
Howie could walk you through that. The coils are strong though, as howie pointed out. Did the shop do that stuff?

As howie pointed out no expensive headwork until correct jetting is established and an ignition fault is ruled out.

[thumbsup]  Heat from lean can cause the glazing. 

koko64

I've decided to disregard everything from the Dealership tests except the dyno run (which I viewed the printout). Just too confusing.

With an overview of the symptoms, leaving out ignition for the moment. If the bike starts witout a/pump priming then jetting changes are required at both ends of the range. If the idle micture screws can be turned all the way in and the bike still runs, or idles faster, then this confirms too big slow fuel jets.
This could explain the uneven plug color patterns.

If I couldn't find a carb tuner I would buy a bunch of jets from sudco or Powerbarn as they are cheap as chips up there. With pods and a flip up tank it aint gonna get easier.

I pmed BN re jets to possibly buy if he has to do it.
2015 Scrambler 800

Rudemouthsky

Quote from: koko64 on November 18, 2013, 11:25:39 AM
I've decided to disregard everything from the Dealership tests except the dyno run (which I viewed the printout). Just too confusing.

With an overview of the symptoms, leaving out ignition for the moment. If the bike starts witout a/pump priming then jetting changes are required at both ends of the range. If the idle micture screws can be turned all the way in and the bike still runs, or idles faster, then this confirms too big slow fuel jets.
This could explain the uneven plug color patterns.

If I couldn't find a carb tuner I would buy a bunch of jets from sudco or Powerbarn as they are cheap as chips up there. With pods and a flip up tank it aint gonna get easier.

I pmed BN re jets to possibly buy if he has to do it.

[thumbsup] already have the 162 and 165's.
"while there is a lower class, I am in it, and while there is a criminal element, I am of it, and while there is a soul in prison, I am not free." -Debs

koko64

When you get the bike back, after throwing in the main jets, do this little test.

With the bike warmed up and idling, screw the idle mixture screws in all the way seating them gently. If the bike still runs, or the idle picks up speed, your slow fuel jets are too big. If it falters or cuts out they are in the ballpark at least.
If they are too big, I would get some 52s and 55s to try.
2015 Scrambler 800

Rudemouthsky


   Going back to the original query;

Bent valve(s) could possibly cause these symptoms?

thanks...

"while there is a lower class, I am in it, and while there is a criminal element, I am of it, and while there is a soul in prison, I am not free." -Debs

ducatiz

you have lint on your electrode.  that's your problem.

Quote from: Buck Naked on November 17, 2013, 04:26:26 PM
To be honest I can't tell. :/. But it looks like oil.

Ok, let's try again...







???


Check out my oil filter forensics thread!                     Offended? Click here
"Yelling out of cars, turning your speakers out the window to blast your music onto the street, setting off M-80 firecrackers, firing automatic weapons into the airâ€"these are all well and good. But none of them create a merry atmosphere of insouciance and bonhomie quite like a revving motorcycle.

Rudemouthsky

"while there is a lower class, I am in it, and while there is a criminal element, I am of it, and while there is a soul in prison, I am not free." -Debs

ducatiz

Check out my oil filter forensics thread!                     Offended? Click here
"Yelling out of cars, turning your speakers out the window to blast your music onto the street, setting off M-80 firecrackers, firing automatic weapons into the airâ€"these are all well and good. But none of them create a merry atmosphere of insouciance and bonhomie quite like a revving motorcycle.

brad black

Quote from: Buck Naked on November 20, 2013, 09:42:04 AM
   Going back to the original query;

Bent valve(s) could possibly cause these symptoms?

thanks...



if it had a bent valve it wouldn't idle.

sounds like it just needs to be tuned to me.  but a leak down test will confirm any sealing issues.
Brad The Bike Boy

http://www.bikeboy.org