125-200cc Plugs loading up

Having a small issue ATM ladies & gents. Plugs keep loading up in low rev tight single. Fine when on the pipe. Newish piston & ring, squish at 1.2mm, new plug with correct gap, reeds good etc. this ishappeeninf after both going from 165 back to 125 & also from Castrol TTS to Rock Oil Synthesis 2 Injector 2T oil(both at 32:1). Both oils are similar as in full syn oil injection compatible. Reckon it'll be ok to run 40:1? Does anyone know the flashpoint of this Rock Oil Synthesis 2 Injector? Can't go leaner on lectron as it starts lean bogging. Was fine as in not fouling plugs as a 165 so I'm assuming it's a higher flashpoint oil but can't find specs.

the only real reason for a plug to load up is a rich condition, which it sound like you have under control
or a weak spark, don't assume the plug is fine, ever, could have been a box that was poorly handled
check your spark, make sure it's bright and can hear it
I would not be afraid to get a spark plug from a different source if I wasn't absolutely sure

I've tried 3 plugs now & spark seems good.

I'm inclined to try some TTS on same track it's been fouling on but that's another $30 I gotta spend plus I've got 15L of the Rock Oil to get through! I might try 40:1 & see if any different. Reluctant to go any leaner on oil for a 125!

Oh yeah it's an MS3 rod in a 38mm Lectron. I'm sure I ran same settings a coupla years back with no change to performance when briefly went back to 125 from 165 with no issue which was leading me to think the oil may be the culprit

Nah very little spooge & dry black carbon when ridden hard on the pipe(plug light cocoa brown after WOT run!). Yeah think I'll try 40:1 with different fuel see how she goes. I just worry when riding it hard.

40:1 shouldn't be a problem unless you're WFO all the time. I just 60 hours on the 165 using Dominator @ 50:1, no probs or noticable wear except the ring.
I'm betting it's the new oil or some shit petrol

Wow 50:1 on the little motor! I do some racing which can be flat out for long periods so guess I'll just chuck 32:1 in for them & I'll try 40:1 tomorrow for the trail its neen fouling plugs on. Got some different fuel too!
Is 1.2mm squish about right? I know a few run them at 1mm

Yeah, and just got confirmation it worked fine. Sent the top end back to Dr WB:
"Hi Steve,
I pulled your top end apart. The cylinder has so little that you might as well call it no wear." And that's @ 110 hours total on the 165 kit. Raced it 6 times last year, 12 hours or so, twice in the sandy pines of SC.

Not sure on the squish for 125, I think 165 is supposed to be 1mm. I'm getting ready to find out.

If I was racing flat out for long periods, I'd be on the 300

125 squish should ideally be not more than 1mm.
Did you use the correct 125/144 base gasket? The 165 uses a much thicker gasket.

Yeah used skinniest(& last) gasket I had which was 0.5mm. I'll order a gasket kit when I put a new piston in in another 10-15 hours that hopefully will have a 0.3 gasket in it. I might but a 1L bottle of TTS to varify if it is indeed the oil.

Keep in mind our fuel is crap compared to you Yank fellas so 1mm might be a bit tight & cause pinging/det. 1.05-1.1mm I think is what Wally sent my 165 top end over for due to fuelling issues on previous Aussie bikes. 1.1-1.2mm I'd be happy with

Nah none of that shit Noobee unless you really look for it!

Ride faster ... Try 40 :1 with synthetic . I liked more natural Maxima Castor oil.
125 should be able to run a closer squish too

Yeah I've ordered some 0.3mm base gaskets so that should get it down to 1-1.1mm. Castor blend smells nice but I've found fouls plugs easier than normal full syn unless you riding hard.

Our octane rating is lower/different than yours Noobee so our 98RON premium is similar to your 85-92 I believe

Are you still running the MS3 rod Shawy ? If so I would think thats the problem.
The 165 for what ever reason seems to want a load more fuel in the mid range area hence the need for the MS3 rod, The 125 needs a thicker rod in the mid section from all my testing with both engines BUT for the life of me without pulling a rod from a carb I cannot remember what I used on the 125 setup

Yeah still MS3 mate. Anyone ełse running a lectron on WR/CR125 care to share what rod they have in?