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[bullethead]

For the 3rd time I've had a problem starting my classic 500 bullet - resolved when I changed the spark plug. I changed the carb prior to all this so any suggestions what the problem might be?

[ChrisD]

Assuming the carburettor jets were correct, how about the slide?
ChrisD

[Craig]

Many Posts ago People where On about Duff Spark Plugs (Of Many Makes)all i Know is This: Never Had a Problem On ANY £%) I have Owned or ridden But I had a 2003 500 in about 2009 and It would Sundenly stop (A Bit Like running Out of Fule) Cleaning the Spark Plug Led to either Lumpy running or NON Start..BUT! Bang a New Plug in and "As Good as New" Some Lasted weeks others Month's Old Rusty Indian MINDa Years....Carb Was a Micarb,Most Plugs where NGK..But I did Try Others "Artical Some where Blamed Modern Fuels Contamanating Modern Porcelin on the Plugs...BUT To repeat Never Had this Problem on a 350???? But Have Heard of More than a Few 500cc Lot With it..NEW PLUG Varooom No Prob (Till Next Time) Enjoy..Craig

[Tim NZ]

With out seeing the bike and looking at the spark plug...
Too rich, too lean, too large a gap (what happens with a .018" plug gap?) 'rotted' end of the HT lead in the coil, too much resistance in plug cap/lead, dirty points, failing coil, loose earth wire, damaged condencer, incorrect timing...
ALL can have an effect

[Norm]

Drop the needle in the carb 1 notch, I found that my crossbred would kill a plug if I the bike was under load, climbing a sligt grade and I opened the throttle a little too quickly, kill the plug and no cleaning of it would get it to work properly again

[simon]

It's very tricky tuning old fashioned carbureted bikes for modern lead free fuel. The carbon that is deposited on a rich mixture is incredibly conductive. Tuning the Bullet for the big 389 AMAL was tricky but nothing like getting the 32 mm Delortos to work properly on the 860 Duc. The trouble is that you only get one shot and then the plug is dead. Despite cleaning them with with all sorts of methods the carbon is so fine that running them up on a megger they all seemed to have lost resistance. And it's not like the damn things are cheap! The most interesting sign that the apparently spotlessly cleaned plug was still fouled was putting it on a mains powered merger and turning it up until the plug started to arc between the insulator and the body. It produced a tiny but bright white light like a carbon arc lamp and once that had burnt out the plug was fine. Not too good for the megger though so not a solution. I did get both bikes working fine in the end but I do have a large box of Seemingly perfect looking spark plugs waiting for a method to clean them.

[Norm]

Simon, exactly right, the Honda Supersport boys are suffering similar problemsin fact a bloke in Sydney was complaing about plug problems this morning, and he has spent thousands on his motor and now he is collecting boxes of dud plugs. Problem with these bikes you can kill 4 plugs at a time

[simon]

I've got a mate who has a neon light transformer somewhere in his collection which would produce sufficient voltage. It would seem burning them clean might be the answer but the actual electronics are beyond me. He (the chap with the transformer) is a bit of a clever bugger and has made many useful things. His capacitor discharge re magnifier for the old magnetos is a case in point. I'll see if I can get him on the job.

[jaffa90]

Problem starting, after trying is the spark plug wet with fuel? Also have you a blueish spark with a little crack noise?

[Craig]

YES "I Think Simon" is right on the Button ..Good Tech report & Norm... But My 350s Left down the Bottom of the Garden (GB: so in Rain,Snow &Flood)Start One or Two Kick's after Years of being Left Inc Old Fuel..While the Pamperd 500s (Shead & Lean to ,Daily use etc) Quite a few Start Prob's over the years (All Bikes Have Mix Carbs Amal/Mycarb & NGK/Other Plugs) and IF IF Carbon Build up efects Bikes my old Lawn Mower has not had aplug Chop or clean in 20 years and runs (Sort of ) fine....(The Bikes I leave for Years I do Fill Carb with WD 40 and they do Start easy after LONG Lay ups in the Open)...Cheers all Craig