is this piston salp??? pics

[blaster82]

i think this is my problem(sarcasticly) is this what piston slap looks like and what is the most probable reason for this to occur

 

[regal81455]

your cylinder would appear to be " out of round "...hone it if it's not to deep or have it bored to be sure its " true "...your "washing" your piston becuz its not a truely circular bore...were you getting good compression still?

 

[blaster82]

yeah i was getting like 50-75lbs, but idk what it was supposed to be, it is already bored .20 over

so if i just get it honed i wont need to buy a bigger piston, just a .20over piston, or should i just get it bored to .3 or .4 just to make sure

 

[Jabes]

its supposed to be from 120-150 psi for the compression

 

[taekwondo dauber69]

you can just hone it.and maybe get by but the scratches go up and down so if you dont want use oil and possiblly lose some compression then go ahead and bore it.you will gain power do that any way

 

[Mootsman]

First of all, you need to have a qualified machinist check the cylinder with either a dial bore gauge (most accurate) or a telescoping gauge on both axes---parallel to the crank and perpindicular. This will tell you how far out of round you are and what the minimum over bore should be. Increasing compression ratio (milling the head) will go further towards making power than increasing the bore a couple of thousandths of an inch.

 

[newnick]

Does the piston have the score marks on four corners?

 

[blaster82]

if i dont have to bore it i dont want to, i want to keep it bored as little as possible and it is already .20 over so i dont wanna have to go up much if any at all

 

[regal81455]

as mootsman said you really should let a qualified machinist check the depth of the scratches in the wall ( does your fingernail catch them if you run it over them?? ) if the scratches are deep enough honing will not be enough...check with a local machinist, if he's a good guy he'll tell you for free what the minimum to get by would be...just looking at it I'd say bore it to the minimum thats required...this way you know the cylinder is true...bore should cost you only about $35-55.

 

[pittboss45]

If you have more that .004 thousandths clearance then it bore time. Those marks look a little like cold siezure to me.

 

[blaster82]

is that from just starting it and taking off when its not warmed up yet?? what does cold seizure mean??

 

[tjsdaname]

I wondered the same thing myself

 

[newnick]

That sums it up, not letting the motor warm up enough

 

[blaster82]

i always let it warm up enough, i let it idle for like 3mins(even in the summer) and then i pump the throttle to like 1/4 to 1/2 for bout a min and then i go, but i still take it easy for the first few mins before cracking on it