Hitchcocks Forum

So after finally getting my bike finished after almost a year out, I've been experimenting with the jetting on my Carb recently. First up I had replaced the the exhaust down pipe with a free flowing one and mated this with a reverse mega phone type, I liked the look but certainly didn't like the sound so I replaced the mega phone with the standard OEM exhaust till my new shiny replacement from our hosts arrived. Whilst I waited the few days I tried out different combo's of jets and tested with short runs and checking the spark plug etc. Too rich, too lean then back to being too rich again but it was all valuable experience gained on how my carb was working. Anyway new exhaust arrived and was fitted which suited the bike perfectly and another round of testing began. This round was a complete bitch, first of all it backfired through the exhaust (ok too rich) made a few adjustments and it started to back fire on start up through the carb( too lean?) a few more adjustments, just as I thought I had a handle on the whole process things went badly. Whilst taking her out for a run around my local town she was running pretty good, a bit lumpy lower down in the RPM's followed by smaller pops coming from the exhaust ok some more tweaking required no probs I thought, it was at this point as I was waiting to turn right at a junction the engine just died. So engaged neutral and pushed it to the side of the road, for the next 2o mins or so I tried everything to get her going again, battery was drained by constant turning over, tried kick starting her but nothing. I basically gave up and started to push her to a mates house, at this point whilst going down a slight down hill section the bike slowed and I jumped off to start pushing again, as I did this and my right leg hit the ground there followed a small pop from somewhere deep within my right calf followed by a large amount of pain, bugger. How I managed to keep the bike upright I don't know but after pushing the bike to my mates a lot slower and with a definite limp, I took a trip to A & E.
I've torn my calf muscle, 6 weeks at least till it's fixed and I'm on crutches too. I was hoping to get some riding time in this year but it seems the fates have other ideas. As you expect I was a bit upset but what I want to know has anyone else experienced issues with the engine just cutting out like that?
PS my mate jump started the bike fine and rode it back to my house, said it was struggling at idle and kept stalling, I also checked the spark plug and it's slightly sooty which after reading the various posts on this forum I'm lead to believe what we are after?
Any idea's?

Yes having gone through a very similar process without the leg damage I would suggest that you have fouled the plug. There seems to be an extraordinarily conductive soot produced by the modern unleaded fuel when it runs too rich. I've put plugs that I cleaned carefully on a mega only to discover they are still at a dead short. I would question what jets you are changing in the carb though. The idle and mid running jets should not be dramatically altered by a change in exhaust flow. I know there is a common practise of changing the main jet on the older iron Bullets when they are opened up and this I would suggest will only affect the running above half or three quarter throttle. My suggestion would be go back to the original carb set up and then enrich the main jet by small degrees from there. I await a storm of contrary advise

Broke my hip doing much the same thing, Electra facing down hill, going to try roll starting it, went to get on, leg got stuck behind the single seat, tried lifting my leg higher, bike moved forward slightly, sidestand folded up and I was under neath it. Another reason why I hated my Electra

@ Simon
I've checked the Spark plug m8, it's slightly sooty and giving out a cracking spark as its virtually brand new (1week old). I basically took the advice from the Hosts Catalogue as to what jets to use. I fired her up this morning and she started straight away but then started spluttering and died on me again after an initial warm up period. I changed the needle jet setting back to where it was with the washer now second from the bottom and ran her up again, this time she behaved better once I tweaked the Air/ throttle screws but I noticed the exhaust fumes were slightly black/ sooty so I'm guessing that its still too rich.
I have a colour tune device which has also confirmed its running rich, if I replace all the jets back to the original ones then I actually get the colour tune to a nice blue colour which is perfect but the spark plug runs very clean ie no soot or blackness showing after a run.
Next question is do I trust the Colour tune device and run it as it is or do I aim for running slightly rich as others suggest on the forum?
Sorry for the noob questions but being a complete novice on anything Carb/ Royal Enfield related I am just wondering which is the best set up to go for.
@ Norm
Sorry to hear about the broken Hip, I guess I'm lucky to get away with just a ripped calf.
I have noticed a massive disadvantage personally with the foot pegs on the Enfield as they seem to stick out so far and I keep getting my legs/ feet caught by them when I'm stopping or manoeuvring in a tight space. I actually chopped an inch off the left side which seems to have helped and my foot now sits snug under the gear change too.

If the plug runs clean and the bike revs out without spluttering and it doesn't spit or turn your header blue after a fast run then I'd say it's set right. I don't think setting it rich is a good idea at all as it will increase bore wear and use excessive fuel. Remember though that the idle adjustment is a totally different circuit than the fast running so a sooty smoke at idle is just a matter of dialling back the idle mixture screw not changing the needle height or the jet sizes.