broken piston

[ero blaster]

I took my engine apart and found my piston skirt broken and I'm not sure what happened to the rest of the piston...could it gone out the exhaust?the engine ran but didn't run long and smoked really bad,i also found that my bore was 66.70 and it had a stock piston what size piston should i get? Help please and thank you

 

[blasterkid1998]

Time to pull the bottom end apart and sent the cylinder out for a bore

 

[ero blaster]

Time to pull the bottom end apart and sent the cylinder out for a bore[/QUOTE
And just get a.30 over Piston?or a .40?

 

[Herpderplol]

Send the cylinder to KOR or bring to a reputable shop to have measured and bored. they will be able to order the correct piston (if they are reputable)

take the whole bottom end apart and will have to be cleaned, probably new bearings

its amazing it ran at all

 

[ero blaster]

And just get a .30 or.40 over?

 

[ero blaster]

Yeah i can't believe that it did either....how much does that cost?

 

[Larry's Shee]

I took my engine apart and found my piston skirt broken the engine ran but didn't run long and smoked really bad

The excess smoke is a good indication that the missing piston chunk may hav cracked or broken the engine case.
Only have the engine bored enough to clean it up. Virtually no difference between a stock bore and .100 overbore.
Highly suggest new crank seals while fixing it, cheap insurance.

As to price, bore, piston gaskets = less than $200

 

[speedyslyder]

how did you measure cylinder??
and how did you measure piston/or is it stamped on top??
sounds like improper clearance tolerances/between cylinder and piston
and the rest of it might have cracked your cases/and or is deff debris in bottom end.
http://www.wiseco.com/ProductSearch.aspx

 

[ero blaster]

It would smoke from the exhaust pipe only and i hope nothing else it's messed up but i think i will take it apart and check......and its that what Ken O'Connor charges?

 

[ero blaster]

I measured it with a digital caliper and the piston had a number on the top but i don't think that it could be right t has 75 stamped on the top but art in the inside and 37f01 and when i researched it it kinda lead to be stock but I'm not sure please correct me if I'm wrong

 

[ero blaster]

[GAL

 

[ero blaster]

 

[ero blaster]

 

[ero blaster]

how did you measure cylinder??
and how did you measure piston/or is it stamped on top??
sounds like improper clearance tolerances/between cylinder and piston
and the rest of it might have cracked your cases/and or is deff debris in bottom end.
http://www.wiseco.com/ProductSearch.aspx

any more input?

 

[tbrooks]

Your gonna need to split cases to inspect and put new bearings and seals

 

[ero blaster]

Your gonna need to split cases to inspect and put new bearings and seals

Why new bearings?there is no play on the rod and it rotates really easy

 

[Awk08]

broken skirts result in a few things.....

* the simplest is the skirt gets caught before it enters the bottom end and locks up the rod/crank
(if the full piece is found, you may gamble)

* the broken piece being chewed up into a million tiny pieces by the rotating crank (miss even one small piece and it may wipe out your main/rod bearings and the new top end = more $)

* it enters the bottom end and pieces are forced thru the cases into the counter balancer or transmission areas
creating a huge air leak (which will also quickly ruin a new top end = $$$)

since you didn't find the broken piece, chances are very good it got chewed up by the crank, you need to split the cases to clean out any and all remaining pieces, inspect the rod bearing, and for case damage/cracks, and while your in there replace the main bearings and seals.

unless you win the lottery weekly, don't gamble with this, you will lose.

 

[jus_me]

You will have to split cases to get the rest of that piston out. The skirt most likely broke because of excessive piston to bore clearance. It was slapping around in there. It is best to split it and do the bearings while you are in there because there would be chunks of metal all through the bottom end. Maybe not trans side because it is sealed from the crank case but since you said it was smoking bad leads to believe either you cracked the case (trans side and or anywhere) or the trans side seal is bad. either way you need to split it and find out.

The littlest pieces of metal take out bearings. Better to be safe than sorry. There is not much clearance between the crank/crank webs and the cases. The thickness of the piston skirt itself is more than enough to take a case out.

 

[jus_me]

^^ Im a half a second late.

 

[ero blaster]

broken skirts result in a few things.....

* the simplest is the skirt gets caught before it enters the bottom end and locks up the rod/crank
(if the full piece is found, you may gamble)

* the broken piece being chewed up into a million tiny pieces by the rotating crank (miss even one small piece and it may wipe out your main/rod bearings and the new top end = more $)

* it enters the bottom end and pieces are forced thru the cases into the counter balancer or transmission areas
creating a huge air leak (which will also quickly ruin a new top end = $$$)

since you didn't find the broken piece, chances are very good it got chewed up by the crank, you need to split the cases to clean out any and all remaining pieces, inspect the rod bearing, and for case damage/cracks, and while your in there replace the main bearings and seals.

unless you win the lottery weekly, don't gamble with this, you will lose.

Ok thanks......would it not be Better to buy another running engine?