stuttering issue - with video

[xjwmx]

It's interesting. To me they don't look oily, but whether they are or not should be obvious to him there holding them... After just 70mi. hmmm.

My best guess would be insanely rich or a bad coil. But if you had a bad coil it wouldn't idle well with plugs in that condition, like you say it does. So that leaves insanely rich. I would go back to stock jets and needles and make sure I didn't put the carbs together wrong previously. Like maybe wrong needles and seats or bad measurement techique on the floats. Check that the rubber plugs are in and so on. Check that you have the right mix screw if they aren't capped off.

The TCI has been known to cause high speed stumbling that seems to be tracable to a weak rotor magnet. Don't think it would have the plugs looking like that though if you ever ran it at a lower rpm where it wasn't missing...

 

[deadchef]

Hate to use the O word and would like to see a sharper pic but those plugs look oily.... how does the spark look? If it's fat and blue the coils probably fine. Never hurts to run it in a dark area and look for high voltage leaks. Spritzing with water from a spray bottle will show them up in a hurry

how can i check the spark? i am assuming that i keep the plug attached to the plug wire but hold the plug against the engine somewhere instead of having it screwed into the head? does it need to try and run or just turn over quickly to watch spark?

as for the h2o spritz, any place in particular that i should focus or spray?

what is the O word? oil? as in my rings are shot? maybe, and i'll find out more tomorrow when i check the compression but i haven't seen or smelled any blue smoke out the exhaust.

 

[deadchef]

It's interesting. To me they don't look oily, but whether they are or not should be obvious to him there holding them... After just 70mi. hmmm.

My best guess would be insanely rich or a bad coil. But if you had a bad coil it wouldn't idle well with plugs in that condition, like you say it does. So that leaves insanely rich. I would go back to stock jets and needles and make sure I didn't put the carbs together wrong previously. Like maybe wrong needles and seats or bad measurement techique on the floats. Check that the rubber plugs are in and so on. Check that you have the right mix screw if they aren't capped off.

The TCI has been known to cause high speed stumbling that seems to be tracable to a weak rotor magnet. Don't think it would have the plugs looking like that though if you ever ran it at a lower rpm where it wasn't missing...

the only jet i have changed is the main. currently i have 135's in there. the plugs aren't oily, just black carbon. which is odd also considering, as i understand it, should suggest a rich condition.

i've had these carbs apart several times. each time trying something a little different with no change. a week ago i even had the floats set at 27mm before it was pointed out by 5twins that the manual is incorrect so i set them at 22mm. made absolutely no difference. i've tried the cap off the tank with the petcock set at prime, on and res with no change.

i'm starting to go bonkers!

 

[gggGary]

Well you sure have tried a lot of things! How about one more easy one? cap off the vacuum port and run the petcock on prime. Just to see if it makes any difference. As you seem to be on this like a dog worrying a bone. Here's another thing to mess with. Try the stock airboxes, tear the rest of the mouse hair off the filters and wrap some foam from a lawnmower filter around them? If you have hte carbs off shoot us some pics? Just clutching at straws I guess. Something allowing an enrichener to stay open?

 

[xjwmx]

i'm starting to go bonkers!

Well I had a situation where the coil was bad, measured good but must have had internal high voltage pathways. It would run ok with new plugs but they would quickly foul and not run. The breakthrough was when I realized it had to be the coil, because it was acting fouled before they started to look fouled.

But - it ran better at high speed than low, wouldn't idle in fact, and with plugs like yours wouldn't have sparked at all But if you're 100% sure the carbs are in the ballpark, including stock main, then the coil is a possibility. Doesn't hurt to have a spare one around anyway.

 

[gggGary]

On spark test, yes plugs out laying on engine is fine, just crank the starter. Or you can leave one in and watch the other with it running, which might reveal if one cylinder runs better than the other too.

 

[deadchef]

ok, figured i'd tear the carbs down while everyone watched...

diaphragm test

carb slide

slides & needles removed
needle identifier - 5hx12

float height - sorry, only had standard but it's about 7/8" or 22mm

needle jets - 270 y-0

float valve body - new

bowl view

pilot jets - 42.5

air mix screws - now i did notice one of them is missing that tiny little black seal but i can't believe it would cause the kind of problem i'm having.

slide view

i forgot to get a pic of the main jets but they were 135's. everything is clean and ready to go back together. see anything off?

thanks for all responses!!

 

[gggGary]

It all looks good to me.
By the way I think you just won the "best pictures AND video by a guy asking for help while working on his carbs" contest!

 

[nic81xs]

i bet those uni's will solve your problem. mine had a similar problem with those cheap pods. uni's made a huge difference! i wasn't a believer until i got them.

 

[xjwmx]

i bet those uni's will solve your problem. mine had a similar problem with those cheap pods. uni's made a huge difference! i wasn't a believer until i got them.

Except he already said it does it with nothing on at all.

In the float height pic, you have your finger on the float. Needs a re-do. Also - I don't see 22 anything on the scale. Are you converting it to inches or something?

 

[deadchef]

Except he already said it does it with nothing on at all.

In the float height pic, you have your finger on the float. Needs a re-do. Also - I don't see 22 anything on the scale. Are you converting it to inches or something?

i have my finger on the float holding it up so the tang just touches the little spring button on top of the float needle. the ruler is in inches and i was converting. 7/8" is pretty close to 22mm. also, when i had the floats set at 27mm there was no change.

 

[deadchef]

It all looks good to me.
By the way I think you just won the "best pictures AND video by a guy asking for help while working on his carbs" contest!

well i certainly appreciate all the help! got the carbs back on and ready to go but it's late and my neighbors don't appreciate me farting loud let alone revving my bike. first thing tomorrow morning i'll let you know the outcome.

 

[xjwmx]

You hold the carbs upside down when you do the measurement, and you absolutely do not put your finger on anything while measuring! I don't know how close 7/8" is to 22mm but 1/2mm makes a big difference. 2mm richer than 22mm would cause what you're seeing on your plugs.


But if it makes no difference if it's at 27mm and if you measured that accurately, which is a big if, then you have leaking needles and seats - if it's fuel related.

But I repeat - you aren't measuring right!

 

[deadchef]

You hold the carbs upside down when you do the measurement, and you absolutely do not put your finger on anything while measuring! I don't know how close 7/8" is to 22mm but 1/2mm makes a big difference. 2mm richer than 22mm would cause what you're seeing on your plugs.


But if it makes no difference if it's at 27mm and if you measured that accurately, which is a big if, then you have leaking needles and seats - if it's fuel related.

But I repeat - you aren't measuring right!

i followed this from littlebill

 

[xjwmx]

^I don't know what it says there, but if it differs from what I said, it's wrong! Really.

 

[weekendrider]

xjwmx
Look at the picture again. He is measuring upside down.
Unless in his world the main jet pointing at the rafters is upside down.
His finger keeping the float from depressing the sealing pin.
Or the nephew slipped something in my Prince Albert can again.

 

[xjwmx]

^All I've got to say then is keep the finger off! Let gravity do what it wants with the pin.


Something is very messed up. What do you think it is, Weekendrider? BTW, we will have to get together on my sojourn back up North.

 

[plattey]

Try unplugging your regulator/rectifier. If that clears the stuttering, then the trigger magnet is weak and the pickup coil can't find the trigger magnet's field in the rotor's field. This happened to mine whenever I tried to change lanes because the electrical load caused by the turn signals would demand more power from the charging system. The regulator would send more current to the charging rotor which would increase the strength of the rotor's magnetic field. The pickup coil couldn't find the trigger magnet in the rotor's magnetic field and the ignition timing wouldn't be correct and caused the engine to stumble and sound like a 18 wheeler with the jake brake on. What I ended up doing was cleaning the surface of the trigger magnet and jb-welding a small rare earth magnet from radioshack and that cleared up the issue.

 

[xjwmx]

^When that was going on with you, did your plugs look like that? I doubted it could cause that and that's the only reason I wasn't emphasizing that possibility.

 

[plattey]

wheww that was a while ago, but pretty sure that they weren't black like that. well, like what was said earlier in the thread, check the float height and make sure the floats don't have fuel inside to make them sink.