Jump to content

Blown top end, why?

By HONDALOVER17,
in Kawasaki 2 Stroke

 Share

Recommended Posts

Enthusiast

HONDALOVER17

Posted
Posted

Hey guys so I did my top end on my kx250 and I did the first heat cycle then realized that that my crank seal was blown so I took apart the bike and took the new piston out. Then I got new cranks seals bearing ect put the slightly use piston back in and then I started up the bike on the stand, it ran for a 5min and then it died I tried to kick it on but nothing, then I checked the compression it was at 90 and ya just never turned on. Btw I got the cylinder honed too. HELP ME!!

Link to comment
Share on other sites
Enthusiast

HONDALOVER17

Posted
  • Author
Posted

Hey guys so I did my top end on my kx250 and I did the first heat cycle then realized that that my crank seal was blown so I took apart the bike and took the new piston out. Then I got new cranks seals bearing ect put the slightly use piston back in and then I started up the bike on the stand, it ran for a 5min and then it died I tried to kick it on but nothing, then I checked the compression it was at 90 and ya just never turned on. Btw I got the cylinder honed too. HELP ME!!

Link to comment
Share on other sites
Proficient

Swes

Posted
Posted

Crank seals normally don't require crank removal .

Take the thing apart and the answer is there . All I can thing of that would kill it that fast is

Piston wrong size

Didn't hone properly

Or honed a nikasil

Didn't oil when putting together

Dirt!!

Piston in wrong

Really lean and burned out

Most likely it's a combo of these

TBH most of the time something that fast is normally either user error or something was worn out and didn't get replaced with the rest of the stuff

I'd just take it apart and see what sort of damage you got and be more careful rebuilding .

Who honed it ? How ? Did you measure everything ?

Btw if you honed a nikasil jug that would do it

Link to comment
Share on other sites
Enthusiast

HONDALOVER17

Posted
  • Author
Posted

Crank seals normally don't require crank removal .

Take the thing apart and the answer is there . All I can thing of that would kill it that fast is

Piston wrong size

Didn't hone properly

Or honed a nikasil

Didn't oil when putting together

Dirt!!

Piston in wrong

Really lean and burned out

Most likely it's a combo of these

TBH most of the time something that fast is normally either user error or something was worn out and didn't get replaced with the rest of the stuff

I'd just take it apart and see what sort of damage you got and be more careful rebuilding .

Who honed it ? How ? Did you measure everything ?

Btw if you honed a nikasil jug that would do it

I dont know how but I got it running I just kick it about 100 times lol and it started right up and idle
Link to comment
Share on other sites
Proficient

Swes

Posted
Posted

shut your face if you dont like it dont look at it

With all due respect there's a good reason for this rule and being hostile about it is a good way to get banned or have your posting abilities taken away

Link to comment
Share on other sites
Grand Master

Ud_Luz

Posted
Posted

shut your face if you dont like it dont look at it

You won't be posting much longer with this attitude. 

 

Read and follow or you're out of here.

 

What are the rules concerning the use of this site?
 
No personal attacks. If you debate, attack the topic, not the person.
 
No unauthorized commercial/promotional use of ThumperTalk. Members must not use the discussion forums and/or private messaging as a vehicle to promote or advertise the products, services or events of any business that they are directly or indirectly associated with. If you'd like to reach our members with your message, contact us.
 
No trolling. Trolling is starting threads or replying to posts with the purpose of getting a rise out people. For example, starting a thread titled "Yamaha Riders Suck" in the Yamaha bike forums.
 
No non-sense posting. If you don't have anything of value to add to a thread, don't reply just for the sake of posting. It's just more fluff readers have to weed through to find the information they are looking for.
 
No posting for sale, free, wanted or trade ads in the forums. Ads are only permitted in the classified section or your profile signature.
 
ThumperTalk is a PG13 community. This means no excessive profanity, vulgarity, graphic or sexually explicit content.
 
No cross-forum posting (creating the same thread across multiple discussion forums).
 
Moderator conflicts. Should you have a conflict with a moderator, work it out with that moderator. If that fails, contact the site administrator.
 
No unauthorized group buys.
 
We reserve the right to monitor, delete, edit, move or close any post, thread or private message for any reason. In addition, we reserve the right to block or restrict any user from access to ThumperTalk for any reason.
 
If you post something that ThumperTalk deems unacceptable, that post/thread will be deleted and you will be told why via private message. While we don't expect you to agree with any particular action we take, we do expect your cooperation and acceptence. Any bitching, whining or pissing & moaning about it will result in your immediate removal from ThumperTalk. This includes taking your case to the streets (public) in an effort stir the pot and disrupt the community.
 
ThumperTalk is a private club and we reserve the right to determine what is and is not appropriate for our discussion forums. If you don't like what we do or how we do it, please exercise your freedom of choice and find something that better suits your personal tastes. If you have a suggestion as to how to improve ThumperTalk, post it to our suggestions box.

 

Bottom-line, treat others as you'd like to be treated yourself, use common sense when posting/replying and have fun! 
Link to comment
Share on other sites
Grand Master

turbo dan

Posted
Posted

Did you take it apart yet?  90 psi compression means you have a serious problem.  Either the rings are stuck or the cylinder wall is damaged.  Rings can get stuck if you have a foreign object in the cylinder that gets mashed against the cylinder head.  This can collapse the rings lands and stick the rings.  If something got into the motor while you had it apart that would do it.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

ThumperTalk

Register a new account Sign In Now
 Share
Go to topic listing
×
×
  • Create New...
Terms of Use
Copyright
Privacy Policy