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wet plugs

Started by jack02, June 07, 2011, 02:50:01 AM

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jack02

Riding to and from work last week,I gradually became aware of a dischordant note from the motor that I couldn't pin down. When I got chance I started it from cold and touched each downpipe near the head with a wet finger. All but number 4 was instantly sizzling hot ( though that too was getting hot,only less so). Whipped the tank off and swapped plug caps (no time to do more) but the problem remained. Got worse quite rapidly over the weekend.  Whipped the plugs out yesterday and all except No2 were wet - No4 was dripping wet with fuel. Any idea what's happening here chaps? This time last week it was running so sweetly...

Thanks,J.

irishluck

im only assuming here but check and see if its getting spark, if its not getting spark, it wont burn fuel which results in a wet plug.  pull the plug wire off that one, stick a screw driver in it and put it right next top the engine casing, turn the bike over and just see if its getting spark.


Mark Olson

keep it simple , install new spark plugs .
Mark O.
86 fj1200
sac ca.

                           " Get off your ass and Ride"

jack02

Thanks... I'll be putting new plugs in tomorrow. When I took them out at the weekend,I did install them in their caps and laid them on the head whilst cranking the motor. All plugs were sparking (they look OK,gap correct etc) but in the light of day the spark looked yellow and not very healthy. Is it possible/feasible that all four could go down at the same time?? Battery is fairly new and showing 12.8v after standing,bike starts on the button. I'll see what the new ones do but is there anything that springs to mind that could cause a weak spark across all four further up the ignition chain? I'm already contemplating pulling the carbs ( a job I hate - especially refitting the buggers) to check for stuck float needles and the like.

Arnie

Where is the battery showing 12.8 ?  At the battery or at the coils?
Check the voltage at the coils and maybe do a relay set up to get full voltage there.

As for your hate of carb removal, you do know that removing the upper sub-frame bolts and bending the subframe down to the wheel will give you some room to work, right?

Cheers,
Arnie



Quote from: jack02 on June 07, 2011, 03:33:16 PM
Thanks... I'll be putting new plugs in tomorrow. When I took them out at the weekend,I did install them in their caps and laid them on the head whilst cranking the motor. All plugs were sparking (they look OK,gap correct etc) but in the light of day the spark looked yellow and not very healthy. Is it possible/feasible that all four could go down at the same time?? Battery is fairly new and showing 12.8v after standing,bike starts on the button. I'll see what the new ones do but is there anything that springs to mind that could cause a weak spark across all four further up the ignition chain? I'm already contemplating pulling the carbs ( a job I hate - especially refitting the buggers) to check for stuck float needles and the like.

jack02

Arnie,the missus hasn't been to collect my new spark plugs yet (!), but I've checked the voltage at the coils as you suggested and... I'm getting 9.5v from the white connector block and 0v (that's right- zero) from the yellow one. Now I know I'm tired and stessed - finished my night shift five hours ago and still four more before I get chance to get my head down,but even I can recognise that somethings not quite right here! What's going on?? The bike was running ,albeit badly when I put it away. I split the 'bar switch cluster while I was out there and got 11.8v at the kill-switch. The mere mention of electrics makes me shrug my shoulders and look more gormless than usual (being colour blind doesn't help) but I can run to fitting a relay. Do you perchance have a link handy for instructions,and have any idea why I'm getting the results outlined above? I can really feel a migraine coming on over this. Oh,and thanks for the tip about refitting carbs, I had a look for the bolts you said and can see how their removal will aid proceedings greatly - did not know about that trick!

Thanks,J.


jack02

Thank you andy - just what I was looking for. Just so happens that I have a new relay lying around  and I'll fit it tomorrow all being well and report back with the results.

RichBaker

Quote from: jack02 on June 07, 2011, 03:33:16 PM
Thanks... I'll be putting new plugs in tomorrow. When I took them out at the weekend,I did install them in their caps and laid them on the head whilst cranking the motor. All plugs were sparking (they look OK,gap correct etc) but in the light of day the spark looked yellow and not very healthy. Is it possible/feasible that all four could go down at the same time?? Battery is fairly new and showing 12.8v after standing,bike starts on the button. I'll see what the new ones do but is there anything that springs to mind that could cause a weak spark across all four further up the ignition chain? I'm already contemplating pulling the carbs ( a job I hate - especially refitting the buggers) to check for stuck float needles and the like.

I'd put money on the fuel inlet valve(needle seats) o-rings leaking...... Have you ever replaced them?
Rich Baker - NRA Life, AZCDL, Trail Riders of S. AZ. , AMA Life, BRC, HEAT Dirt Riders, SAMA....
Tennessee Squire
90 FJ1200, 03 WR450F ;8^P

andyb

Start with plugs.  Strikes me that at least one was fouling out.  The next question then is why is it fouling.  A crap connection, weak power at the coils, or a huge excess of fuel.  Also simply old plugs wearing out.

One thing at a time though.  New plugs, the relay mod isn't a bad option to improve things a pinch, and if you're continuing to see horrifically bad mileage, crap power, and/or leaking gas, then it'll be time to start looking at the carbs.

jack02

Well,a day late but I got me new plugs this morning,but before fitting them I installed the ignition relay. Being utterly incompetent with all things electrical,the job took me three hours and I'm afraid the new wiring around the headstock ain't too pretty. Functionality over aesthetics, I say...

Anyways before I started I got me voltmeter out again to check that there was no power at all going to one of the coils - twas still the case so the wire twixt kill-switch and connector must be broke. Not to worry as I only needed the feed from the other coil wire to operate the relay. When I'd done I laid the shiny new plugs onto the cam cover and gave the motor a twirl before fitting them. BIG,FAT,BLUE sparks! Fitted the plugs,pressed the button and the ol' girl fired up instantly. After the realization that she hadn't burst into flames as a result of my hamfistedness I went into the house for a smoke and a brew to get over the shock while she warmed up. Five minutes later I went back out and again applied the went finger test to the downpipes - all were uniformly hot. To confirm that my fingers weren't lying I applied a match to each to see how long they would take to ignite. They all did just that on contact! At that moment it started raining,the timing of which I find incredible since we've had barely a drop (a drought order just been issued here in the UK) since,oh it's so long ago I can't remember. So I didn't go for a ride but I can say that the tickover is amazingly steady and throttle response is instantaneous and utterly glitch-free. I thought it was ok before this trouble but apparently not,compared to how it is now.

Thanks for all your help,without it I'd probably still be scratching my head now. I'm really happy about not having to pull the carbs but at least I've learned a trick to make that future inevitability much easier (cheers Arnie!).

irishluck

awesome!

we actually had a friends bike that wasnt getting spark at all, had a bad ignitor. expensive little things. Good luck with riding!