250-500cc Where do I start?

Rito went riding again today on wr300(2010). Ran ok for the most part but started missin again at WOT. I'm not sure wher to look first. Has done it last 2 rides since installing lectron bowl bracket. Was sure everythin was clean wen reassembled. Possibly bit of dirt in PJ tube? Seems odd that it only does it intermittingly tho? Runs fine for a bit then starts playin up. Other thing I was thinkin was the filter for fuel pick up? I have a spare filter n washer(I think it is) that came with the carb. Bike runs sweet down low but wants to foul plugs if doesn't get cleaned out with good rev. It's kinda like it's choking or sumthn(either not gettin enough fuel or too much).
Had new gapped plug today n it nearly fouled but managed to save it by revvin it's tits off for a few seconds n Ridin gear low. Havnt touched rod n only adjusted PJ 1/8 turn leaner ride or 2 ago(at 5/8 from seated which wher it's bn give or take 1/8 turn for years). No spooge out exhaust which is stocker pipe n fmf pc2.
32:1 full syn 98 octane. Will try 40:1 but bn runnin 32:1 for years so don't think it's that. Mayb 1/8 turn leaner? It's winter here now n pretty cool but normally u richen for cold weather don't ya(due to thicker air)? Unless it's gone rich due to temp drop(10-15 degrees C from 30-40 in summer).
Float seems ok as in level in bowl looks the same. Flow outta tank is normal in on position but may try a ride with it in reserve to eliminate that. Unless it's plug cap/ignition/coil/stator?

Sorry for long post but jus tryin to get my head around this. Got enduro sunday was plannin on usin this bike for but may hav to use 165 if can't fix

Your tank breather not blocked? As soon as it starts doing it crack the fuel cap and see if that cures it.

Il double check but don't think so. Bit hard to crack the cap at WFO tho!

Should mention piston still looks good thru exhaust(which is well sealed) but economy seems to have dropped by around 20%! Bike still goes hard no loss of power

It's she any easier to kick?
Could be rings on there way but usually it screams more up top.
Have you got an inline fuel filter?
Your coolent not being sucked through your o ring again?

Nuh coolant sweet(got new rad cap 1.1 bar which lower than stock but not a drop lost). Nuh she still got plenty of compression!
No filter.
Wonder if condensation in tank could be it? Fuel was coupla months old. Can't see anythin in bowl tho

Don't know if that is helps http://www.cafehusky.com/threads/lectron-carb-tuning-guide.32064/

Love to help ya out more as l don't have a Lectron; on my Keihin carbs, your first comment "Bike runs sweet down low but wants to foul plugs if doesn't get cleaned out with good rev. It's kinda like it's choking or sumthn(either not gettin enough fuel or too much)" bothers me as this indicates that the bike is running rich in the middle and therefore way too rich at WOT causing fouling - it's building up (richness) which is the cause of the fouling. Do you have a baseline setting to work off?

PS..don't fall for the trap of changing ratio's...if the bike's been fine running at 32:1 then it aint that!!

Inspect the vent pipes as well

Old gas First thing to eliminate before you chase your tail too much. Does sound like carb tuning with the plug fouling My 300runs so much better with 3-1xl rod (and fresh rings), starts right up, idles easy, runs clean bottom to top. Actually a little rich on top, but that's ok.

Will check vent hoses n tank breather(blow em out) today but fairly sure they're ok. Ran tank near dry yday so will get fresh fuel n try it. Runs same with gnarly or stock pipe. Still starts first kick n idles ok. Wen I say it was ok in bottom end I mean it was runnin ok in single track wher luggin in 2/3 gear at 1/4-1/2 throttle but could feel plug loadin up n wen tried to open it up it was stuttering like tryin to clear it's throat. Felt like lack of fuel(like wen runnin out switchin to reserve) more than too much fuel but doesn't explain plug loadin up. I'm shit house at diagnostics so may very well have been too much fuel. If I go a half turn leaner on PJ I'm half turn out from fill lean which I ran it at for a while with no issue so maybe try that? Never ran like this before was pretty clean from bottom to top?! Winter u normally go richer don't u as air thicker?

Nah no ethanol mate, not that I know of anyway!

Juicy I havnt touched rod since u were here maybe 1/4 turn łeaner if anythin so unless temp drop has affected it(not much of temp drop tho) then I'm beat. Fuel blockage would make it leaner

Wouldn't be an ignition or plug cap issue would it?

PJ is from 1/2-WOT isn't it? So if it's loadin up Ridin singles at low throttle openings that would indicate too rich on rod wouldn't it? Then wen go WOT the plug is oiled up n takes a bit to burn it off hence the stuttering/missing? I did up the idle a bit could that affect it on idle n downhills(like too much fuel gettin in n not bein burnt)?

Ahh these things shit me n I don't wanna get an hour into a 4 hour enduro(with 6 hour round trip) n hav to nurse it or swap plugs out every lap!

Shawry remember that in hot conditions and then elevation changes causes the air to be thinner meaning you need to adjust the air screw out too allow more air int the carb (leaner), the opposite is true as well cold conditions.
If in doubt:

1. Turn in the air screw and count the number turns to close point and turn it back out to this point i.e 1 1/2.
2. Start and warm up the bike.
3. Set the idle adjuster so the bike is rev'ing a little high (around 1200rpm)
4. Now, turn out the air screw until you hear the bike start to increase rev's (count the turns!!)
5. Turn it out a bit more and the bike should start to flutter or slow.
6. Turn it in until you hear the bike increase rev's and steady again.
7. Turn in again and the rev's should slow.
8. Go back to Point 4.
9. Shut the bike down and count the number of turns in.

At certain points you will need to blip the throttle but always make the adjustment when the idle settles however, that point where the bike started to rev higher (Point 4) is the correct air/fuel mixture for that temp and level.
If the air screw is out more than 2.5 turns then you need a smaller pilot jet, if it' only 1 turn out then a larger pilot jet.
A weak spark can certainly cause fueling issues up top but it doesn't explain your fluttering at 1/4-1/2 throttle...generally a weak spark will cause misfires.

PS. Again, l don't know how to tune these Lectron cos l don't have one but the above is basic carb tuning.

I think PJ is 3/4-WOT. Stock is 1 turn out on the PJ. If mine is rich on the bottom it's harder to start. I didn't have to adjust my 300 for winter/summer.

Yeah got me buggered as didn't adjust it last year. Mite jus pull the bowl n check it's clean(pick up filter, PJ tube) n rod is facing the right way!

Yeah she all nice n clean so I'll pull tank n check it out. Il get photo of plug too

doesnt apply to lectron at all...no air screw, no jets

pj operation depends on how far tube extends into venturi. when slide rises enough to allow flow across tube, the pj flows. pretty sure most lectrons are set up to be 1/2 and up, i have swapped in a shorter tube so mine is about 2/3 and up. you can get different tubes from lectron to make the begin at any throttle opening.
shawbagga, next time you are able to look in carb, look at how long the pj tube is. this will tell you exactly where your pj operates and will help you tune.

Right, but pretty sure Dave at Lectron told me PJ was 3/4 and up stock. I was wrong once before though