FZRSupport: the FZROnline Archive

This covers the same problem as the carb thread, but I have a spark plug question.
I changed the gas tonight, made sure the carb boots were on tight the set befor the carbs and after the carbs.
I decided to take her out on a very short run. Well she felt like she was running on only 3 insead of 4. I pulled the plugs, I will hopefully find some replacement in the am. I know that you can tell alot from a spark and how the engine is running. I have never replaced the spark plugs since I have had the bike, almost year and half. So what do the spark plug gurus think from the looks of my spark plugs?
Thanks guys in advance.

Does autozone carry our type of plugs. I really don't want to go to the stealership, they should right?

Just check online autozone sells them. Anyone know the gap of hand.

look here we talked about spark plug and who has what and from were
viewtopic.php?f=38&t=820&st=0&sk=t&sd=a&hilit=autozone

Too rich.

Looks too rich to me

Thanks Guys

ALMOST wrote:Thanks Guys

Almost,
The guys are saying too rich BUT actually that is not saying much as the plugs are too old and used for a GOOD diagnosis as to where the bike is rich.

I can make plugs look like that by idling the bike on choke for too long, idling along at 5 mph in heavy traffic.

Suggestion for you buy precious metal plugs, be sure to gap them correctly (across yours they look to vary, but that may be camera ). Warm the bike up with a ride, then change to one set of plugs.
start the bike NO choke and set the idle leave for 10 mins. pull the plugs and thay should be alight coating that is dark tan not black. You do this thro out the rev range to see the plug readings.


When you test you ride up to that throttle level stay at that level for 5 -10 mins then shut the engine down pull the clutch & stop (called a plug chop ) & check the plugs.

For details of plug reading see :-
http://www.saltmine.org.uk/jennings/spark.html

written by Gordon Jennings

The reason for using precious metal plugs (iridium plugs) is the center electrode will stay cleaner for longer, not require such good spark current to fire and allow the plugs to be indexed easier.

OK who is the wise guy who can tell me what that "indexing" is about ?

OK who is the wise guy who can tell me what that "indexing" is about ?

Indexing is marking the plug's gap direction and then installing the plug to see which way the gap faces when installed. And then choosing plugs which point the gap in a specific desired direction. Useful in some engines where the plug may be subject to dynamically different 'wash' conditions. It especially pays off in two strokes. Squish banded four strokes also benefit from proper plug indexing.

On our bikes' tight little pentroof combustion chambers one would be hard pressed to find an 'ideal' index, imho.

Yeah, plug chopping is the best way to make a call as far as 'rich' or lean. But, in my experience, plugs that look like Almost's are never getting to their self cleaning heat. He's definately not lean at the middle ranges where most street riding is performed.

reelrazor wrote:On our bikes' tight little pentroof combustion chambers one would be hard pressed to find an 'ideal' index, imho.

RR,
right on the nose, just wondered if anyone had actually tried it on the FZR. was worth a little extra on the Yamaha SECA that the Venemoto Yamaha engineer did for us unofficially


as to Almosts plugs one of his plugs is cleaner than the rest in the last pic centre one.............may be newer ??

as to Almosts plugs one of his plugs is cleaner than the rest in the last pic centre one.............may be newer ??

I was wondering about that one myself. It almost looks as if it is a different brand...seems to have a different ground electrode. I was actually thinking older as the edge of teh center electrode is rounded off a bit more. And it doesn't look as if it was properly tightened as you can see it is discolored the full length of the threads and the other two (? where's #4?) , not so much. It not being able to shed as much heat may account for its' cleaner appearance (getting closer to self cleaning temp).

RR,
right on the nose, just wondered if anyone had actually tried it on the FZR. was worth a little extra on the Yamaha SECA that the Venemoto Yamaha engineer did for us unofficially

I would think that regarding spark/ignition I think more would be gained by eliminating the waste spark, thereby allowing denser saturation of the coil and a single path across ONE gap to ground.

reelrazor wrote:

RR,
right on the nose, just wondered if anyone had actually tried it on the FZR. was worth a little extra on the Yamaha SECA that the Venemoto Yamaha engineer did for us unofficially

I would think that regarding spark/ignition I think more would be gained by eliminating the waste spark, thereby allowing denser saturation of the coil and a single path across ONE gap to ground.

RR,
I must admit that "waste spark" has always been a bit of a niggle but having asked several Yamaha JP & venemoto engineers all I got was shrugs and economics as an answer. It seem they thought the extra engineering of a having one shot per cylinder was too much. Thinking now about it it may have had to do with the limits of revs & the speed of electronics in those days as compared to the switching frequencies we can do now.

Lets face it 2 stroke bikes (street) had what 11K top end revs before they grenaded. now we see 4 strokes with 16K revs and no problems the world has moved on , do yamaha R1 / R6 use wasted spark these days ?
If they do it is probably to keep the coil numbers down for space saving ???

Well new plugs, still not running on all 4, removed the carbs and clean them again. not sure what next. Any idea yamaha george. Some thing simple, some thing I have over looked. Maybe it is the carbs and I just don't see it.

ALMOST wrote:Well new plugs, still not running on all 4, removed the carbs and clean them again. not sure what next. Any idea yamaha george. Some thing simple, some thing I have over looked. Maybe it is the carbs and I just don't see it.

Does it clean up anywhere in the rev range? Are the plug caps in good shape(one isn't arcing to ground?)? And, is the engine fundamentally sound(compression good on all four)?

Which header pipe(s) is cold? That is going to pinpoint your miss.