146cc BBK Problems.

[Dabomb]

what have you tried?
have you tried a thicker or twin base gasket?
shaved the top of the piston?

 

[East50s]

Dabomb.
The head gasket looks like it is not located properly on the dowells.It looks to be offset to one side.Looking at the gasket opposite the cam chain side the gasket appears to be encroaching on the cylinder bore.
Do us a favor and take a pic of the opposit side of the cylinder looking down at the piston crown [The top of the piston !]...You may find the piston crown is coming into contact with the head gaket causing the knocking sound !!
If the piston has been coming into contact with the headgasket there should be telltale marks on the Piston crown or the underside of the head gasket fire ring [The stainless steel sealing ring part of the head gasket !]

Hope this helps .
Cheers Brian Welcome To EAST 50s

 

[Dabomb]

wen i took the head off it didn't look like the pistion had hit the head gasket.
i spoke to Andrew at Big50 and he shed some light.
the oil gallery seal and metal ring must be removed (between the head and cylinder) because there is no recess for it to sit in.
also said that the tapping noise could be from the auto decomp on the stock cam.
going to get a metal head gasket from him

will take photos of piston and head gasket on weekend when i tear it down again.

 

[themountain]

also said that the tapping noise could be from the auto decomp on the stock cam.
QUOTE]

but the akunar cam don't have that and the thing about the oil gallery seal was in the post I linked, if you ever read that , Einstein!

 

[Dabomb]

went back to stock cam.
thanks alot.

 

[coolmodee01]

see brother
ya just gotta ask the right people the right questions

and mountains right it was in that post

now wasn't the noise happening with the akuna cam in it ????

 

[Dabomb]

was/is happening with both cams.

 

[liljohn_92]

mine was hitting and it was the piston hitting the head gasket

 

[liljohn_92]

hey bro got it running??


i had mine goin yesterday sooo loud

 

[Dabomb]

hey man,

ive had it running but ive got that tapping noise still.
it made good power and that when i rode it but ye.
its down in the shop gettin fixed at eastcoast50's atm.
urs runnin good?

 

[liljohn_92]

i had it goin yestrday but it needs a mega tune and ii still cant ride cuz my bro stole my chain ahah ... guna get mine tuned by a mate probly this week

 

[Dabomb]

sweet as, i had 2 trim the bottom cooling fins to fit over the start motor!
hopefully mine will be done by mid week and will be all good 2 register.

 

[liljohn_92]

ye sweet as aye ..

hey what carby are you runing cuz i need a new carby but duno wat to run on mine

 

[Dabomb]

runnin the stock mikuni 25mm rip off, you?

 

[Dabomb]

hmmm was lookin at a genuine kehin PWK26 to match port, but mite just stick with the stock carby for now.

 

[liljohn_92]

yer in just guna try tune my molkt in and see if it works

 

[Dabomb]

ye it should run easy.

 

[liljohn_92]

it did when i went down the street before just gotta get the mixturer right ..

it only runs on choke and when you turn choke off it revs up then dies

 

[Dabomb]

let it warm up a bit

 

[themountain]

it did when i went down the street before just gotta get the mixturer right ..

it only runs on choke and when you turn choke off it revs up then dies

your carb runs too lean...put a bigger pilot in