Help! again

[hi_im_sean]

so i got the hybrid all put back together. did my heat cycles and break in yesterday, all went great, bike ran great, started right up.

i go out for a ride today and it quits a miles from the truck. was running fantastic, till all of sudden it just died. it died real quick, and locked up for a split second like a seize, but then loosened. i roll to a stop and check all the norms, gas on etc. go to kick it over and it feels like it has no compression at all, just spins free as hell. go back get a tow strap, friend tows me back, as we are towing back i tried to pull start it and it fires right up, just like low compression. it again seems to be running good, but wont idle, and cant kick start it. so i ride it around a little and it seems to clear itself out, will idle and start with the kicker, and the kicker actually has some compression resistance, so i think ok *** maybe ill ride it around the truck a couple miles to make sure its ok. right after i thought that it dies again the same way. real quick and locked up the back wheel for a second. fells like it has no compression again.

took it home and my buddy helped me look at everything and all seems fine. has spark, took the pipoe off and the piston looks good, its getting oil, has a few scratches in it, more than i like to see on a just broken in motor, but nothing that would keep it from running. everything seems normal, just no compression. i was gonna pull the head, but im so angry i just walked away and grabbed a 12 pack.

[N4TRBL]

Sorry to here about that.

Rings could be toast from a cold seize.

[martinfan30]

Whats the actual compression?

[no1clyde]

Take the head and then the cylinder off and look everything over real good. Just a question but did you check the ring gap before you put it together? Make sure your rings are free on the piston too. Check the reeds too, they can cause trouble with compression by letting the air out insted of making it go into the cylinder. Good luck.

Ed

[hi_im_sean]

i dont have a comp guage i was going to borrow one and get an actual reading before teardown, but i know compression is low, motor spins way too freely, and it only starts when you tow it.

yes i checked the gap, they were in spec. brand new reeds, but ill do what you said, complete tear down and inspection:foul: ? x a million, and some of this ??? ?

[hi_im_sean]

here si the complete build

https://www.thumpertalk.com/forum/showthread.php?p=7720833#post7720833

[no1clyde]

Also sean take a real close look at your lower rod bearing. It can cause it to lockup and then release and cause lower compression by noy taking the piston all the way to the top.

Ed

[Jeekinz]

That blows man. What piston are you running?

[Jeekinz]

Is the waterpump good?

Skirt looks dry in your install pic. I don't "bath" my parts, but I make sure everything has a coating on it.

[hi_im_sean]

Is the waterpump good?

Skirt looks dry in your install pic. I don't "bath" my parts, but I make sure everything has a coating on it.

skirt was dry, bore was oiled, water pump seems to work, and it should, rads get hot quick (well normally), doesnt make any noise, was rebuilt last top end, you think its getting hot? that was my only guess, im stumped here

in my defense (cuz i know this is coming) my drz has ran great for 2 years (10000 miles coming up soon, about 60% is dirt) only the kx has given me issues, the case cover breakage is my fault

[no1clyde]

I also had the thought that maybe a crank seal is leaking air and making it lean and then hot. These kind of things can drive one nuts.

Ed

[hi_im_sean]

I also had the thought that maybe a crank seal is leaking air and making it lean and then hot. These kind of things can drive one nuts.

Ed

thats what a friend said, i just didnt want to believe him, he wanted to get a leak down kit, maybe i can convice him.

[no1clyde]

sean have you looked at the pressure test your 2stroke stickey in the Honda 2stroke forum? Any way I made one a little differently by using a low pressure (like a blood pressure tester) pump through the spark plug hole and plug the intake and exhaust. A mighty vac that makes pressure works too and also a low pressure regulator works with a air compressor. You just need around 5 PSI. Good luck.

Ed

[hi_im_sean]

sean have you looked at the pressure test your 2stroke stickey in the Honda 2stroke forum? Any way I made one a little differently by using a low pressure (like a blood pressure tester) pump through the spark plug hole and plug the intake and exhaust. A mighty vac that makes pressure works too and also a low pressure regulator works with a air compressor. You just need around 5 PSI. Good luck.

Ed

ill check it out thanks

[hi_im_sean]

well i made that thing for $14 at home depot, and the plug from autozone for $7. did a leak down test, and the only leak is the kips shaft seal. i checked everything else except the tranny side crank seal, nothin else leaks. before the rebuild that seal was puking oil and leaking real bad and the bike ran great, i replaced that seal when i rebuilt, so i dont think thats the issue, any ideas? ill ake some opic of the doohickey when i find my camera, what a great idea

[Jeekinz]

Pull the head.

[makKX250]

Quick question and not trying to be an a-hole but why would you keep trying to ride it when you knew something was wrong?

You aren't going to know what is wrong till you pull the head and cylinder and see what kind of seizure the piston has had.

[hi_im_sean]

Quick question and not trying to be an a-hole but why would you keep trying to ride it when you knew something was wrong?

You aren't going to know what is wrong till you pull the head and cylinder and see what kind of seizure the piston has had.

i know, i know. in my defense i ran it for less than a mile, so i didnt really keep riding it

will puul it apart when i get time