spark plugs?

gday , just 1 question, last week i had the cam chain replaced in my xj650,it ran great at 1st but slowly started to loose power over the last week, anyway in 5th it struggled to get past 5500 rpm, i thought it may have been cam chain related some how???, anyway i replaced the plugs (old ones were gapped correctly and only about 2000k,s on them,good colour) and now the bike runs as good as new, now the question, what could make a plug just fail for no apparent reason? thanks in advance, ken

 

Plugs fail for no reason, Ken, you fitted new plugs which gave you a nice crisp spark, but maybe your problem was coils related & what is the condition of the battery ?

 

Plugs fail for no reason, Ken, you fitted new plugs which gave you a nice crisp spark, but maybe your problem was coils related & what is the condition of the battery ?

 

Maybe it wasn't the plugs at all but the related tugging and reseating of the wires/caps.

You might want to pull the plug wires and have a peek inside the caps; ensure the resistor cores aren't loose, unscrew the caps and lop a CM or two off the end of the wires to give the caps a fresh "bite."

 

thanks men, heres what ive deduced, battery needed help, cells on post ends were really low, and inbetween a bit better, about 5 weeks since i checked the battery, but have been caning it up the mountains as hard as it would go, could have diagnosed some more but with new plugs and batt serviced its as good as new, i have to admit when a bike of this caliber gives you a problem you expect the worse because they are so reliable.... im just not not use to anything other than turning the key and riding it untill i have to come home . once again thanks wiz and fitz.

 

I tend to forget the battery until it starts turning over slow, then I remember to check the water levels and

 

Cast out your distilled water pilgrim

http://www.motobatt.com.au/

 

just might do that when this ones had it, the one i have needs topping up every 2-3 weeks

 

2-3 weeks? Might be worth checking that regulator.

 

good point , but im doing around 500k's aweek at the moment as hard as it will take me, these are good bikes, ive tested it a few times while its running and it is working as it should,buying the cheapest battery i could doesnt help,,, ,been awhile since ive tested it while its running, may be more like 4-5 weeks between checks when i give it some more thought,,, , funny thing, ive just put another perilli night demon on the rear, (last rear 1 lasted nearly 20000k's and a new cam chain last week , but my new fj1200 turns up this week and the rego runs out on the xj in 6 weeks, so im really enjoying the xj at the minute(ringing its neck) knowing once the rego runs out i may not ride it much ever again , even though its in good nick (BETTER THAN GOOD NICK), i will not sell it though because its in great condition and its worth more to me to just look at it and polish it for the next 20 years, . it is a part of the family. i still dont understand why these bikes dont seem to have as much value as the other bikes from this era, ,,

 

I suggest putting the money into an AGM battery, like from Scorpion. The extra cold crank is nice.

Nice pic, love those XJs. The standards are the kind everyone likes to look at, but for some reason they all want to buy crotch rockets or cruisers. I don't mind, it's nice to have a rarer bike.