MOPED ARMY

yeah, i will definitely check it afterwards. just was wondering if i should have a richer jet ready to put in or not. sounds like i should be okay, i'll just order one afterwards if it seems too lean.

my friend says he may have a pipe from an old 125 lying around.. would that be too large in volume, or be tuned for too high an RPM to work efficiently on the pa50?

another question...

is it possible to swap heads without removing the jug? like.. is the base gasket generally stuck on there pretty well?

if the bore/ports look good (which they should be, it accelerates nicely and runs at 30mph no problem, all stock) i'd rather not have to mess with the jug/piston/rings while swapping the head.

awesome, thats what i was hoping to hear :)

i just bought a spree head on ebay, read on here that they bolt right on and bump the compression a bit. i havent had any issues starting without using the decomp valve, so i'm not too worried about eliminating it

when you say stock airbox...are you implying there's an upgrade?

Also, what are you doing to up the compression?

eventually i may use a hole saw to make a nice big hole right through the airbox so i can fit a small cone/foam pod filter on the carb. for now i'm sticking to the stock unit though... might remove that weird rubber inlet thing with the 3 holes in it though.

i read on here that the spree head bolts right onto the express and bumps the compression, and ive also read that PA50 big bore kits work on the express.... so the spree head should fit the PA50. i'll let you all know how it goes, it should be here next week.

also...

what if i didnt use a head gasket at all, and instead just used some of this stuff:

https://www.amazon.com/dp/B000HBNUDQ/

??

anyone? thoughts on the orientation of the head, and possibly eliminating the head gasket?

thats what i was thinking for the head placement actually. the only other reasoning i could come up with would be to line the fins up in the same direction as the ones on the jug... but i dont see that mattering at all.

i think i'm going to keep the head gasket in there. i want it to be reliable, and i feel like i'd just be asking for a leak if i left it out. maybe i'll make a new one eventually with thinner material.

jb weld?

but that seems to be my answer to everything. Let someone else come to that same conclusion before doing it.

the head was properly torqued, to 9 ft lbs.

i've been reusing the stock hobbit aluminum (?) head gasket, as it was in good shape. i had no compression leaks, but i definately had exhaust/air/fuel leaking out of that decompression hole (i could see/hear it). if you look at the picture of the spree head above, you can see how the sealing surface of the head isnt completely square... the decomp hole is left at least partially uncovered, creating the leak. the hobbit gasket does cover the hole completely, but the spree head does not clamp down over it.

when i get around to replacing that base gasket... am i going to need new rings and/or a cylinder hone to get things to seal properly when i reassemble? the cylinder walls appeared to be in excellent condition.. no scoring, and ports were not clogged at all.

as an aside, i must say that i'm having a lot of fun experimenting with this little two stroke. i have a fair bit of experience tuning high performance turbocharged/fuel injected 4 cylinders (in cars), and the simplicity of these mopeds makes things so much easier. you don't get to do much trial and error sort of experimentation when you're making 165hp per liter... things tend to blow up! nor can you swap the cylinder head three times within the course of a single afternoon to test various compression ratios :).

Hummm. Sounds like you're close then. Take Portland's advice then and JB weld it. If you fuck up the cylinder then I've got some extra ones, and so does every other Hobbit owner who's put a kit on. I'm wondering though if it's going to be really hard to start once you get the head properly installed.

i doubt it will be a problem, ive never used the decompression lever to start the thing, and its not exactly hard to start :P

is riding around with a little base gasket leak gonna hurt anything? i've still been using it to get around..