Running 430 main, 27.5 Pilot and 6BEG9-69 needle 2nd rung from the bottom in a Mikuni flat sided 38 carb with a boyesen Rad cage and a works Pro Circuit pipe. From memory, the air screw's around 2.25 turns.
hey ive got a yz 125 2006 and im going to attempt a top end rebuild but just wondering what do i need to replace it has'nt had any work done since i got it (about a year) is it just the piston i need to replace?thanks
How does it run? if you're having problems (not running clean, rough idle, poor starting) then it may be time for e top end, but before you tear down run a compression test to confirm that it is time to re-build. All of the above symptoms can be caused by carburation issues, especially if the bike's been lying for a while. If you do have to re-build the top end you won't know what needs replaced until you open it up. You may need just a top end kit (piston/ring/bearing/gasket).
i carefully fitted an athena kit to 05 yz a couple of years ago and could not seal the cylinder head for long. the two piece athena head is a poorley supported and a flimsy affair and the o ring would blow between the studs.i ended up machining the yamaha head and using that .porting on athena is not brilliant. where bore is larger it has dropped ports lower especially rear transfer which don`t line up. i was wondering how others have got along with athena,is the head still two piece?
@jasonmccoll yeh, I guess you could call it a 'YZSKY' lol. The Athena kit makes a huge difference by the way, you should consider it when the wife's RM needs a new top end!
"a tin thread. Whatever the hell that is!?" XD words of wisdom man! lol. Nice build! how long did it take you to disassemble reassemble and start the engine?
@sideshow45 It was about 2 hours actual work time, but the parts took weeks to arrive. WTF is Tin Wire? I'm guessing it's American terminology for solder wire? lol
@banfordg you are correct it is solder wire maid out of tin and is real soft like lead but no one like to handle lead any more so they recommended tin wire
but you do not want to use silver solder it is allot harder cold and may damage the piston or head
what did u put in the engine so nothing will get in
crf150r99f 1 year ago
thank you very much helped me out alotttt!!
yz125rider194 1 year ago
what jeting u runnin and what needle position and air screw setting
yz125rider194 1 year ago
@yz125rider194
Running 430 main, 27.5 Pilot and 6BEG9-69 needle 2nd rung from the bottom in a Mikuni flat sided 38 carb with a boyesen Rad cage and a works Pro Circuit pipe. From memory, the air screw's around 2.25 turns.
banfordg 1 year ago
hey ive got a yz 125 2006 and im going to attempt a top end rebuild but just wondering what do i need to replace it has'nt had any work done since i got it (about a year) is it just the piston i need to replace?thanks
ReconSurfer 1 year ago
@ReconSurfer
How does it run? if you're having problems (not running clean, rough idle, poor starting) then it may be time for e top end, but before you tear down run a compression test to confirm that it is time to re-build. All of the above symptoms can be caused by carburation issues, especially if the bike's been lying for a while. If you do have to re-build the top end you won't know what needs replaced until you open it up. You may need just a top end kit (piston/ring/bearing/gasket).
banfordg 1 year ago
i carefully fitted an athena kit to 05 yz a couple of years ago and could not seal the cylinder head for long. the two piece athena head is a poorley supported and a flimsy affair and the o ring would blow between the studs.i ended up machining the yamaha head and using that .porting on athena is not brilliant. where bore is larger it has dropped ports lower especially rear transfer which don`t line up. i was wondering how others have got along with athena,is the head still two piece?
gilessmokey 1 year ago
Sweet! Is it a Husky with a YZ engine.I love that pipe and Athena kit 5 stars bro !
jasonmccoll 1 year ago
@jasonmccoll yeh, I guess you could call it a 'YZSKY' lol. The Athena kit makes a huge difference by the way, you should consider it when the wife's RM needs a new top end!
banfordg 1 year ago
"a tin thread. Whatever the hell that is!?" XD words of wisdom man! lol. Nice build! how long did it take you to disassemble reassemble and start the engine?
sideshow45 1 year ago
@sideshow45 It was about 2 hours actual work time, but the parts took weeks to arrive. WTF is Tin Wire? I'm guessing it's American terminology for solder wire? lol
banfordg 1 year ago
@banfordg you are correct it is solder wire maid out of tin and is real soft like lead but no one like to handle lead any more so they recommended tin wire
but you do not want to use silver solder it is allot harder cold and may damage the piston or head
dexter2433 1 year ago