coils

[bagmaker]

Hey all-
What options are there for replacing coils - anything cheap, free, better or "be warned" - info would be good.
I am suss about one of my coil packs after the shenanigans with the resistor in the plug cap, still not running 100% and I advised replacing the resistor may be band-aiding a real problem with a coil or lead.

So what do I replace them with, best option?

Thanks,

P.S.
I would like to thank all you out there in this great world who have helped me with playing about all things TRX. You are a helpful mob and its heartwarming to me to log on every now and again and link up.
Thump on.

[bagmaker]

could I replace the stockers with something like these??

http://www.ebay.com.au/itm/Yamaha-YZF-R ... 2572ce1b36

[Con Rod]

stick coils are a good option, no idea which ones you would want, have not looked into it

[bagmaker]

has anyone in australia got a spare coil I can try?
The problem could actually be a lead or the CDI, I want to try before purchasing if possible

[M.V.]

has anyone in australia got a spare coil I can try?
The problem could actually be a lead or the CDI, I want to try before purchasing if possible

There's a couple on my bike that work ok, we could swap one out & see how it goes.

Would give me an excuse to do a few other things to the bike that are piling up

[bagmaker]

still battling away,
may take up that offer MV (if the sun ever comes out again)
Could it be a pickup? Has anyone any knowledge of faulty ignition timing pickups?
Seems a strange set of problems for a coil is all, some bloke reckoned "could be your pickup" so thought I would ask the collective

[alextrx850]

still battling away,
may take up that offer MV (if the sun ever comes out again)
Could it be a pickup? Has anyone any knowledge of faulty ignition timing pickups?
Seems a strange set of problems for a coil is all, some bloke reckoned "could be your pickup" so thought I would ask the collective

Havent really heard of any problems with the TRX coils or leads before Bagmaker...have you a heap of Kays up there,? or a corrosion issue...
You are on the right path with a swap over of parts..had a same situ with a TS 185 suzuki once..might go over your EARTH contacts to the coils too..sounds like a gremlin there..[salt over the shoulder]. good hunting

[bagmaker]

its driving me berserk, this problem.
Coils come up OK to spec on resistance, primary and secondary.
Pickup coil in spec as well.
Anyone done a CDI before?

Symptoms
runs fine cold,
misses, farts back through the carbs, etc when warm/hot. Idles fine anytime, runs OK above 3500 rpm.
Carbs replaced, now FCRs
valve shims done (twice)
new plugs (seemed to improve it for an hour)
replace plug cap resistors (seemed to improve it for a day)

a very frustrated bagger

[Con Rod]

are the exhaust headers seated properly and sealing? sounds like a fueling/exhaust problem, not electrical

a rich problem will worsen as the bike heats up

[Mincehead]

its driving me berserk, this problem.
Coils come up OK to spec on resistance, primary and secondary.
Pickup coil in spec as well.
Anyone done a CDI before?

Symptoms
runs fine cold,
misses, farts back through the carbs, etc when warm/hot. Idles fine anytime, runs OK above 3500 rpm.
Carbs replaced, now FCRs
valve shims done (twice)
new plugs (seemed to improve it for an hour)
replace plug cap resistors (seemed to improve it for a day)

a very frustrated bagger

Have you tried swapping the vaccum fuel pump for another or rigged up a gravity feed from a bottle higher than the base of the fuel tank?

[bagmaker]

thanks Mince, but

I dont think the problem is fuel at all-

if it were fuel starvation,
1 - it wouldnt run OK cold / cool. Motor runs well until 60-70 degrees on the gauge.
2- it wouldnt run well over 3500 rpm
3-the sypmtoms are EXACTLY the same with the new carbs, even though they arent jetted spot on.
4- I have a little fuel filter in-line with clear plastic cover, always seems to have plenty in it.

Appreciate the theory though, its what I first thought was the issue and led me down the FCR path.


cheers

[Mincehead]

You`ve done the valve clearance checks so it`ll not be a valve `blow by` issue when hot, mind you could still have compromised valve seating due to past blow by.
Are ALL the component parts of the wiring involved with the ignition circuit clean and free from corrosion?
The running well once past 3500 rpm troubles me, I reckon a weak link in the ignition circuit would make itself known even more at higher revs.
So, I`m erring towards a valve seating problem and you cannot ascertain that easily but here`s what you could try.................

When the motor is up to the `problem` temperature, whip the FCR`s off, then turn the motor over by hand till all the valves are closed on one cylinder at a time, while the valves are closed tip some petrol down the inlet tract and see if it `bleeds` past the inlet valve and seats. They SHOULD hold fuel back at least for a few minutes even if the seating is a tad compromised. If the valve faces and seats are badly compromised the fuel will run past quickly.
Do both cylinders and tell us what you find?

Don`t forget to whip the plugs out and turn the motor over for a while on the starter to clear any excess fuel from the bores before you try to restart it though.

[alextrx850]

Dosent sound like the ignition...im the same as mince..the low speed idleing would be the first to be affected..that and you say the plugs helped for a time...seems like a fueling problem.cam timeing..?...what about the TPS on the side of the carbs.//[timeing position sensor]..do you know how to set it up.??.and are your FCRs new or second hand..??

[Kenny]

If its taking out plugs so fast and runs terrible over 3500 sounds like its way way rich to me. Test it by taking it up high rpm on a the lowest possible throttle positiopn and then come back and tell us at what throttle position it gest bad as jetting isnt all rpm related its more throttle position.

[bagmaker]

Thanks all, appreciate your advice

Mincehead,
It definately gets worse with temperature, but we are only talking cool to warm standard running temperature. As soon as the gauge shows movement the issue becomes apparent.
Between idle and 3500 it just wont pull, any load causes the misfiring. Seems to be from 1 cylinder only but I cant confirm. Serios popping back through the carb (s). Moving off from a standing start is a clutch wearing experience.
Over those revs though, it pulls like a train. I just can't beleive valve leakage would come good over a certain RPM.
AND the idle is perfect at any temperature. Vexing.
The actual head was off a few months back and the valves were all re-seated
I can coax the revs through the problem range veeeerrrrrry slowly (no load) and it will run clean through.
I will put your valve seat test in the basket of things to try, thanks.

Alex,
I agree, doesnt sound spark at all.
Thats why the top has been off twice and the carbs replaced.
Now no TPS on the bike, FCRs straight and CDI modified to bypass advance.
Cam timing triple checked OK, new cam chain less than 2000k ago.

Kenny,
The plugs seem fine, its not "taking them out" I replaced the plugs for the hell of it and "whoa - thats better!" but for a short time only (2 hours) -not fixed, just better.
One plug (left side, I reckon the problem side) was darker than the other, both showing rich but both were on the OK scale of color.
Then went down the plug cap resistor route, replacing them with solid billets of brass. This fixed the problem for an afternoon, now returned with a vengeance though.
I went with the fuel probability for a long time, seems obvios. The old CV carbs were corroded and I couldnt adjust some screws so I figured them the problem.
Replaced!
But with all the carb changes (its not jetted right, now, to be sure - but it was jetted well with the old CV carbs), air filters completely different, FCRs not running TPS, different ends of the clearance spectrum on the valves, different fuels, different ambient temperatures and moisture levels there was NO DIFFERENCE in the symptoms.

The only improvement came for a short period from plugs and plug cap resistor change.

Cheers all