i have carbon plug fouling - the fouling is flat black, not slick to the touch - its chalky/dry

both plugs are fouling*
(i thought i had turned the corner but after adjust the timing i went back to foul city)

ok here is the current setup:

needle (NEW) 2c3

needle clips (NEW) set in the upper most notch (lean)

needle jet (NEW) 105

main jet (NEW) 210

pilot jet 25

enrichers (NEW) seat properly - did the push test - no change

slides (NEW) 3.5

float/needle - functioning correctly - level is correct

throttle cables (NEW) - set with proper amount of play etc

plugs (NEW) NGK B6ES (gap .025) getting good visible spark

coil (NEW) Harley 3ohm (when i purchased the bike it had an accel super coil - Harley - i have no idea if was functioning properly put since i was in process of eliminating possible issues i decided to replace it - it was not new)

plug wires (NEW) metallic

battery- load tested etc - passed, charging/holding charge - its not new but according to the tests is functional

charging system - checked - charging - correct voltage

ignition - stock electronic - not Boyer

if i have forgotten anything please read my other threads

after i installed the new carb parts - i had the local expert over for a house call - he set up the carb screws, sync'd the carbs, checked the valves etc

the right carb functioned perfectly ie the pilot air screw was almost set dead to spec and the plug read perfect

but the left side was another story there was a leak at the bowl gasket (issue has been resolved) and plug fouling - CARBON FOULING

the fouling was almost immediate - from idle thru out the range it would foul and be useless within 5 minutes of ride time

so before i switched the carbs from left to right i decided that i would check the timing

and the timing was off!!!!!!

i adjusted it at 3,600 RPM - set and secured

installed fresh plugs - started first kick and took it for a test ride around the block

from idle to quarter throttle all systems go

anything above approx quarter throttle to full was a NIGHTMARE

the bike ran rough and sporadic, detonation deteriorated, bogged, blat, burp, backed off the throttle and all systems returned to normal...back on the throttle = nightmare

brought the turd home, pulled the plugs and they were both carbon fouled!!

did i just take a step backwards...is this bike cursed..am i cursed??? i know i am broke!!

should i have just bought new JRC carbs!

sigh...HELP!!

mr. tooth

Well...sounds like really healthy rings\bore fit..ports to carb match\et cet..and major pull on the #25 pilot=too rich..get you some#20,and #15 and see which gives you the Tan plugs...

I would think ..... IF.. the local expert is the person you bought the carb parts from...AND is the one who rebuilt the top end ...And is an expert (in the opinion of other experts) I feel if you approach him he would offer to sort it out at little or no cost..a customer who pays and pays and pays and is rewarded with a "TURD" does not reflect well on his reputation, or the viability of British bikes as reliable transportation.
Note the differences between triumphmike's jetting and yours.
In what position in the carb is your pilot jet and undrilled plug situated??
Rick

i bought the carb parts on-line and installed them myself

and yes he and the crew did the top end....they have the experience

i am confident they did the job right .without them this project would have been a complete lose... BUT they are not in the business of restorations and focus on early model - engine overhauls and chops....and if it don't work - replace it.

the pilot jet is in the top of the bowl. i sprayed it with carb cleaner, removed, inspected and made sure it was seated correctly

What sort of pipes are you running? I would think the standard size main jets should be 200 and 210 a bit rich if you are running stock mufflers. 210 is for megaphones.

Also, check to see if your chokes are seating properly.

You numbers are fine. It should run. They will idle with a #15,#20 or #25 idle jet.
220 may be large but you have not reached WOT yet to worry about it. I run a 2C3 needle and it's fine. So...
The enrichening rods on the MKIIs came in two sizes.
The early ones had a shorter brass housing at the bottom holding the rubber seal. The later ones came with a longer housing. Compare the old ones to the new ones. You can push down all you want but the longer ones don't seal the fuel port AND they don't, by virtue of size, seal the side port in the body. This is because they are too big to fit in the recess that you can't see.This might explain the problem.
----
And now for a long shot. This happened to someone I know who consulted an "expert". Are the slides installed upside down? It has happened.
HTH

no mufflers...1.75" open pipes

air filters are ok

oh and the slides are installed right side up.. : ))

No mufflers, 1 3/4" pipes...might suspect your neighbor sugaring your gas tank.

Saw,
Mine:
79 T40D
#15 idle jets
#35 choke jets
3 1/2 slides
2C3 needles mid position
106 needle jets
220 mains
floats .020' to .030" below bowel top
1 3/4 " TT pipes w/ 6" baffles
UNI foam filters
---
I am scratching my head on this one. You are too near my settings. I am back to enrichening rods
or bad needles/seats in bowl. I'll scratch some more.
HTH


HTH

Try removing the air cleaners.

If that don't do it, just keep leaning out the jetting.

Remember, though, whenever you're sure it's the carbs, it's usually the ignition.

Nick writes

Good point. Do you have new condensors?

Swap the carbs over temporarily to be certain it is the carb.

Blapper

My 79 T140D would CONSTANTLY carbon foul my plugs for some ten odd years till I recently switched to Champion N5Cs and copper plug wires, no more problems since the switch. Seemed too simple a fix but it did the trick.

May seem over simple too but make sure your coils are 6 volt.

Rip-Cut Bicuspid -

I have seen two or three people suggest that you swap out the carbs and see if the problem follows....I don't see where you have done this....has this been done yet and if so, what are the results? You would be able to tell alot from this simple task.....

Is a Harley 3ohm coil correct for the stock points set-up? (I have no idea, myself.) What kind of readings are you getting from the coils?

"99% of carburettor problems are electrical in nature" unknown

HTH,

Steve

JT - He's running points....coil(s) should be 12V

er, JB, he's running a 1979 Bonnie to the best of my understanding...stock electronic not "Boyer".... would more then likely mean stock Lucas Rita electronic ignition not points. I may have missed something in the other threads but a 79 didn't run points ignition to the best of my knowledge unless he's converted back to points. If points are the case then make sure your running a 12 volt coils. If you are indeed running the stock Lucas/Rita electronic ignition appropriate for the 79 I'd ditch the "Harley" coil in favor a of two 6 volt units.

my ignition system consists of a coil, amplifier (original to the bike) and reluctor...the local paid experts insist i buy a Boyer (don't test it-replace it) but they could be right

i think 5ohm coil is for pints ignition

i have not switched the carbs left to right because after i adjusted the timing both plugs were fouling again

i've had the most luck with autolite plugs

so todays tasks are as follows

1. install the autolite 405's and pull the air cleaners - check the voltage from the coil (again) - test ride

2. take a closer look at that old amplifier

3. beg the wife for another $150 from the family budget to buy a Boyer

impacted wisdom

Sawtooth, my T140D has the original electronic igniton and I would never swap it out for a "Boyer" unless it was broken. I did have a 68 BSA Thunderbolt the PO added a Boyer to but left the stock 12volt coils in place and that thing would constantly foul plugs till the error was discovered and two 6 volts were added. My understanding is the Harley coil is a 12volt unit. I would suggest you move back to two 6 volt coils. All only IMHO.

I've never been a fan of Rita ignitions. A weak point is the insulator sleeves and washers where the four wires connect on the stator plate. wire eyelets corode and cause problems,
I would think it is running so bad now that an ignition problem would show up with a spark tester on the plug wire. It is a plastic sleeve with one end attaching to the plug and one to the s/p wire. The ends are turned in or out to adjust the gap the spark will have to jump inside the sleeve. Start with the gap about 40 thou and see if spark is constant as you rev it, then open it up to 80 thou and try again, If there is an ignition breakdown you should see the spark stuttering or stopping. These tools are cheap and useful addition to your toolbox.
Electrical components are never or very rarely sold on a, buy it, try it, return it,for refund if it does't cure the problem basis. If a paid mechanic determines an electrical part is faulty, the customer shouldn't be on the hook for it and the non faulty part reinstalled. Fortunately for brit bike mechanics, boyers are a universal fit unlike the computors and ignition boxes on new bikes that can cost many times the price of a Boyer. Rick

morning update: installed an old trusty set of autolite 405's.

and kicked the bike over...first kick

and its threatening rain so i figured i would skip testing the coil and the inspecting the amp and go for a quick test ride

got out the backroads and gave it some gas (ie opened the throttle up to 1/4+) and the turd choked, ran rough, miss fired aka nightmare

i backed off the throttle and the turd ran normal

decided to try it again (open it up) and it got a little better!

did the same thing..back off and then up...and again better! no sporadic firing...no pain

long story short...after a little while i could run thru the gears under heavy acceleration to wot without issue

(did however notice a audible whine coming from the head??)

drove around for approx. 15-20 minutes and brought the tud back to toliet

pulled both plugs and there was still some carbon but the insulators were off white and clean (which was better than when they started..despite my cleaning efforts the old 405's were plenty black)

i know i am not out of the woods...but at l;eat there is hope

the only thing i did this a.m. is go back to the 405"s

_

lets talk about that harley coil...using my voltage testor what sort ofn reading should i be getting from each poll?? 6v's??? or 12v?? I am getting confused..i am reading too much : (

OK, I'm confused. The 79 should have a Rita ignition. But I thought you said it had points?

The last bout of missing was due to fouled plug /plugs. Electricity will take the easiest route to ground, that being the spark will travel to ground on the carbon coating the plug rather than the harder task of jumping the air gap to ground electrode creating spark.
Spark plugs are cleaned of carbon while running the same way a self cleaning oven cleans its self,, by getting hot enough to burn of deposits. Engines not getting to operating temp will foul plugs as will one where the deposits build up faster than they can be burnt off.(burning oil)(rich mixtures).
One can heat the insulators with a propane (or Map Gas) to clean them back to a white condition. Be careful not to overheat the ground electrode. Rick