As Copemech says, be careful opening up plug gaps in bikes, especially magneto ones like ours, they don't have great reserves of "grunt" like a battery/coil system does. Modern Battery/Coil ones like in your car can successfully hit 50K plus volts at a very high current (7 amps or more). This is to fire the very lean mixtures (15.1+) required by road cars. Most cars these days in fact use 1 coil per cylinder to help accommodate this.On the bikes however the system is limited in current and voltage by the source coil which makes relatively low output to drive all the ignition. Its like fitting a resistor plug cap to early systems, this can take the CDI out as a result of drawing more current than the system can safely handle. A wide plug gap has the same effect, the voltage required to ionise the gap and commence spark increases massively with wider gaps. Yes, its true that a wide gap can sometimes mask off a misfire or other symptom but this is temporary as you may well be driving your gear into extinction. Also, keep in mind that spark plugs rarely fail on their own (I know this as I have been fitting them for nearly 30 years now, for a living by the way) Problems are generally caused by some other issue like overly rich mixtures (Carb issues, air cleaner issues) and oil fouling (in 4 strokes mainly, poor oil control - rings, valve guides/stem seals) so if your plugs are failing on a daily basis, don't blame the plug, look for the actual cause! (Think about your car - do you change the plug every time you drive it? If you do you are looking for a problem somewhere as most modern cars and road bikes get 40 000km plus from a spark plug. Considerably more life than we expect from a relatively limited-use trials bike). All plugs are pretty much good these days, of course I have my favourites but that is based on 30 years worth of daily experience seeing what works well and what doesn't. Given that all else is OK with your engine any "correct" spark plug will do the trick for you.
Hope that all makes sense,
Cheers,
Stork
Any way of telling if its a rich mixture, or burning oil, thats killing plugs ?
It still is - no less so for the mapping feature which is no different to other major improvements such as better designed suspension, lighter materials, tyre technology et al.....
I just enjoy riding my duel stage mapped modern bike the mostest.
I cant wait for ABS and traction control, some of the other "improvements"
Warranty claim. I wouldnt be spending money on a 4 week old bike to cure a problem like this, if you hav'nt touched the carb and done anything that could have caused the problem.
I ran at 32:1 for 20 years, same piston, same main bearings. You have to make the decision if the nano second in engine response is worth changing bearings/pistons if you run at 80:1.
Get any reputable brand, fairly tight and stick some plastic shin / knee protectors down the inside. In my opinion, if it isnt hard plastic it wont really do anything.
that is almost as much as a stupid idea as changing from a 4 stroke to a 2 stroke then back to a 4 stroke during a multi day event and hoping no one notices......
This is my 5TA in a heavily modified B40 frame that I shortened and tightened up the steering head angle. I originally bought it off a mate as an unfinished project 24years ago. I lowered the compression, dropped the primary and secondary gearing and fitted an electrex ignition system, apart from that the motor is standard.
I have since given it 2 facelifts, the last one included nickle plating the frame and anodising the rims and parts dark green, probably not popular with the purists!
As for the 350 or 500 debate, although people say that the 350 is smoother, the 500 is so much fun and will pick the front up anywhere in any gear. Even after owning it for so long I still look forward to riding it, and wouldn't swop it for the world [/img]
Most of that is very nice (purist) How does it grip ? Whats are the tank and forks ? Really like the nickel frame, ball park cost and who did it please.
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Iridium Plugs
in General Trials Talk
Posted
Any way of telling if its a rich mixture, or burning oil, thats killing plugs ?