Hey guys.

im speaking to you from the uk

so, I have this x2, it's been a PITA for the few months I've owned in, various mechanical faults, I'm now on engine build 3 and I think it lean seized the other day so now I need to tear it down again.

i won't post pics of the damaged bore at this time but if it helps I will.

anyway so I finally get the ski running properly a few weeks ago and it's like a bat out of hell, absolutely delightful throttle response from idle to flat out, so crisp I couldn't believe it and no hesitation at all.

plugs looked reasonable so it's well tuned and working I'm thinking. I was happy.

then on day 2 I was WOT for about 20 seconds and I felt something go bad, so I slowed down and pulled in, thought I had maybe fuel starved so I filled up but then it wouldn't restart.

after lots of messing about finally got it going but it wasn't right, sure enough, no compression on rear cylinder.

being on dual carbs, I suspect a carb fault.

i am running bn38s

the spec of the motor is

westcoast stacks
bn38 duals
westcoast inlet
stock bottom end
weetcoast ported cylinder
pjs head
westcoast header
coffmans pipe
pjs water box
jetinetics total loss

heres some pics

anyway so I opened up the carbs for the first time last night

both were basically the same with popoff at around 8 psi but the rear carb had a Viton needle so it sealed all the way up to a crisp pop whereas the front carb leaked from 1psi onwards with no real pop

needle and seats are 2.0

Main jets are stamped 10

i will need the help of a round body expert to tell me what the 10 stamp means, I think it might be 0.10mm but I don't know

Most of you guys talk about jets being 120s or 150s etc

does that mean 0.120mm etc??

which means might might have 100s, which is ok running dual I guess

high speed screws were 1.5 turns

low screws were 1.0 turns

i really really hope some of you guys can help me please, I don't really know why it seized if it ran so good, also I don't know what you will make of the carb setup

any help really is appreciated

love from rainy England