Fresh motor trashed

[Crazy lil punk]

I did a top end on my 87R, as soon as I was done rebuilding it, I started heat cycling it, but could only do the blimping the throttle part, 2/3 weeks later I take it to the track to break it in, runs good, then feels like its maybee lossing compression? it has to be pulled to started by another quad because it wont start with the kicker? then it locks up? some one please help me

[kiesta00]

maybe someone messed up on the bore/hone job...? pull the head and see whats goin on in there

[Crazy lil punk]

yeah, I plan on tearing it down the weekend, I am so stunned by this, thanks for the quick response

[kiesta00]

I can imagine what a pain in the butt that is. How was your rod clearance when you took the top end off? Mine was at about .060, so I definitely replaced it...hope nothing is wrong in your bottom end.

[Crazy lil punk]

I think it is the bottom end, because my rod had a little clearence in it, but I didnt think anything of it till now

[86 Quad R]

really hard to make an assessment of things without having a visual of the carnage......

there could be a number of things that could have caused the engine to take a dump.

[daman02]

Your rod can have some clearence on the crank end side to side, but i'm not sure what the tolerance is but should have 0 up and down play. It's semi difficult to check but you can slide the rode to one side against the crank and while pushing to that side try movin up and down. The side to side clearence can make you think you have up and down slack sometimes so look carefully

[wilkin250r]

With so little run-time on it after a fresh rebuild, my guess is a piston seizure.

[daman02]

the crank wasn't new though so i would think the bottom rod bearing is the culprit since he didn't check it for clearance when he put it together

[Crazy lil punk]

Originally posted by wilkin250r
With so little run-time on it after a fresh rebuild, my guess is a piston seizure.

why would it seize? I was breaking it in as the directions in this forum say to. Also, can a 250r be broken in by just riding around slowly like I did my 400ex? or does it have to be heat cycled? because I am obviously not to good at heat cyclcing

[Crazy lil punk]

Originally posted by daman02
the crank wasn't new though so i would think the bottom rod bearing is the culprit since he didn't check it for clearance when he put it together

I will let you know tomorrow when I tear it apart with my pop

[daman02]

the only other thing i can think of that would mess your top end up so fast would be if you got one of the rings out of its notch when you installed the cylinder onto the piston.

[Crazy lil punk]

TEAR DOWN REPORT-

the crank bearing decided to shread itself, then spread it self all over my fresh top end.......

[koh0001]

Man that sucks, Sorry to hear it. I guess the bright side to it could be... Now you can do some of that stuff you've been wanting to do to it!!:D

[Crazy lil punk]

Originally posted by koh0001
Man that sucks, Sorry to hear it. I guess the bright side to it could be... Now you can do some of that stuff you've been wanting to do to it!!:D \

what would that be? throwing all my money at it? lol

[u_want_some]

Just wondering if you done any work to the bottom end? Have you looked at the Service Manual for instruction on how to work on these motors? Just like they told me....Slow down and take your time....It will be much better in the long run!!!

[86 Quad R]

Originally posted by u_want_some
Just like they told me....Slow down and take your time....It will be much better in the long run!!!

couldnt agree more. :cool:

[Crazy lil punk]

I started the break down today, and I got to where the fly wheel is off, and the trans is showing, but can't get the cases to split? I need a manual!!

HOW OFTON DO YOU REBUILD YOUR BOTTOM ENDS?

[u_want_some]

Hey i you can take a pic of both side of the motor...the way it is right now and I will try and help you as much as possible, you can either post them on here or send them to my e-mail: windows_cleaning@yahoo.com. Also, if you check the top of this forum you will see there is a manual, read chapter 8 it will help you alot!!

[Crazy lil punk]

Originally posted by u_want_some
Hey i you can take a pic of both side of the motor...the way it is right now and I will try and help you as much as possible, you can either post them on here or send them to my e-mail: windows_cleaning@yahoo.com. Also, if you check the top of this forum you will see there is a manual, read chapter 8 it will help you alot!!

Hey man, thanks for the help, but the motor and quad are at my pop's garage, and I am at my house, I plan on picking up the manual, and going back to battle with it this weekend.

[atvmxr]

if you got the motor completely broken down and ready to split the cases, usually sticking it in the oven at low temp (~200 or less) for 30 minutes to an hour will help it come apart easier. Although it seems only us single guys can get away with that. For some reason women dont seem to like the smell of burning gear oil in the house.... :devil: