Need HELP seized

[Ims Roll]

 lets start from the beginning, i bought a 2001 kx 500 about 3 months back, (my first 500) i rode it around the block in Reno and it felt llike it had all the power in the world and handled pretty good (me being a HUGE guy really helps) but when i brought it back to Las Vegas i ran it down the street and seized it up, im thinking oh i forgot to jet it. oh well least it will have a fresh top end now, it has a 52 pilot and a 160 main at about 2000ft above sea, needless to say it was a bit lean. so i rebuilt it about a month ago. new hone, piston, rings, wrist pin, needle bearings and gasket kit. i finially get the bike back and together and suddenly the suspension is so bad that it feels like riding a boat even on the street... i tried to fill with nitrogen but no help... soooooo

[Ims Roll]

so i finially get it back together last weekend, new suspension (gold valves race tech springs all new seals n bushing n rubber) as well as a brand new top end.   well i take it for a ride and while it's running it is spitting water out of the overflow... so i bleed the air out over night and it stops. so i assume im good. ride it down the rode do a spark plug test and i have it running good with a charcoal grey colored plug. yummy right. so the following morning i take it down to my favorite test area. a whooped up road full of g out's and other fun things to test desert stuff on. well it's about ehh 4 or 5 miles long. on the way back she seizes up on me again. not even 8 miles into the ride (not running it very hard, and yes i did break it in properly)  so i bring it back tear it apart and first think to myself, water pump? so i pull that apart and everything looks to be up and running fine. could it be the crank seals are leaking by and leaning the piston out>? and if so wouldnt that have made my plug test lean? any help pleaseeeeeeee?

[Motorrad]

What was jetting the 2nd time?

Float hight?

How was tranny oil level after 2nd stick?  Oddly low?

[cbrfrenzie]

What piston and PTW clearance did you run with the rebuild?  I know the forged pistons need a little extra due to their thermal coefficient.

[Ims Roll]

my jetting the second time was 58 pilot 165 main and about 2 turns out on air/fuel screw. float hight (nothing sientific) was pretty high i couldnt get the float bowl to stop leaking so i had to push it as far up as i could get it. the oil was full and looked great not milky or brown. i am cracking into the top end tonight to see what all is dead.                                   i bealive it was a wisco but i would have to check when i'm home but i had steve rezimwikky do the hone and order everything i just slapped it together, but he used to build stock car motors for my father in the 80's and 90's.   i have had a few people tell me k5's can only be sleved not honned, is this true?

[Danger4u2]

They should be plated.  Nickel Silicon Carbide.  Nikasil

http://www.mt-llc.com/

http://www.kawieriders.com/forum/kawasaki-kfx700-v-force/91562-nikasil-vs-sleeves.html

[Polar-Bus]

IMS roll, ya got me all confused,  you bought an initially good running bike, then immediately blew the top end, replaced it, then blew the top end a 2nd time, replaced it a 2nd time, and now you're on your 3rd rebuild ? How did the cyl look when you did the first top end ? Did your "buddy" mic the bore to see if it's in spec ? Did you at any time take compression readings ?  If you feel gouges in the cyl bore with your fingernail, you need to weld and replate the bore (OEM nickasil). If you have a Wiseco/ sleeve combo those can be over bored.  Seems top me like your simply blowing top ends, and slapping parts back together without carefully diagnosing to ROOT cause of the failures (which IMO is NOT your jetting) Yes you were a bit lean, but not lean enough to completely blow a top end...

[Ims Roll]

IMS roll, ya got me all confused,  you bought an initially good running bike, then immediately blew the top end, replaced it, then blew the top end a 2nd time, replaced it a 2nd time, and now you're on your 3rd rebuild ? How did the cyl look when you did the first top end ? Did your "buddy" mic the bore to see if it's in spec ? Did you at any time take compression readings ?  If you feel gouges in the cyl bore with your fingernail, you need to weld and replate the bore (OEM nickasil). If you have a Wiseco/ sleeve combo those can be over bored.  Seems top me like your simply blowing top ends, and slapping parts back together without carefully diagnosing to ROOT cause of the failures (which IMO is NOT your jetting) Yes you were a bit lean, but not lean enough to completely blow a top end...

i have only done one complete top end rebuild, the top end the first time just looked to be a little to lean and alot to hot. i just pulled the top end apart last night and it looks the same... spark plug is charcoal grey and the piston rings are melted to the piston and cyl walls scorred pretty bad. ill have opics up today

[Motorrad]

The motor I got to rebuild for usmc500 died (the reason i got it, not the one i built) because the previous owner just slapped a forged piston (wiseco)  in a cast piston bore (oem) ...  

Needles to say .0015" piston to wall don't cut it for forged


What's your piston to wall clearance


Also you can't trust plug reading if you got it that hot

[Ims Roll]

it was a cast piston in a oem bore just honned a little. i trusted the spark plug cause it was running amazing... maybe 2 good to be true huh... when it stopped i could hear water boiling but it sounded as if the rads were only half full but i bled the motor n rads several times an am 98% sure all the air was out of them. i did notice upon tear town yesterday that the air filter was ripped. could it have tore open even farther under powerband and leaned it out? or perhaps my fuel mixure was even toooooo rich? i mix 91oct with motul 800 at 32:1 an my kx250 loves it and it seemed as if the k5 did too.

[allan1353]

Could of it been  cold seized?

[jonny500]

check the coolant pump, maybe the impeller is damaged

[weymouth399]

I've only quickly read this, but I have not seen or herd of a leak down test being done during all this.     
I'm new at this, only 30 plus years. But I think it should be done to eliminate a few questions. Seizure from lean condition, out of the blue.Thats a good reason for a leak down test to me. 

Bob W

[Ims Roll]

leak down test i have not buddy

[Polar-Bus]

I've only quickly read this, but I have not seen or herd of a leak down test being done during all this.     
I'm new at this, only 30 plus years. But I think it should be done to eliminate a few questions. Seizure from lean condition, out of the blue.Thats a good reason for a leak down test to me. 

Bob W

I was thinking the same thing, overheated engine melted/warped crank seals sucking air ? Now we read about a "torn air filter"     Too many unknowns and stories with this engine issue to really help. Impossible to help without some type of correct 2 stroke engine systematic diagnosing...