more 250sx problems

[skidoo99]

hey all, ive finally finished my rebuild of my sx. i ended up using the top end from my 85 and the bottom end of the 87 motor. once i got it running i can hear a loud ticking noise from the top end. the top end is rebuilt and the valves adjusted properly to 0.03. the only thing i can think of is the timing chain. are there any differences that would affect it. the motor runs great and idles nicely. i noticed the chain tensioners were different so the leads me to thing the chain sliders may be different and allowin the chain to move around. please help

thanks

[Addicted]

My 84 200x has been ticking since 1991, it's been fully apart about 3 times, then in 96 I gave up, she's still running strong

[Headsup]

.03? Inch.? I am thinking thats to small.. If im not mistaken its like .05 or .06 maybe, Or maybe im thinking of teh spark gap... Idk ill have a look then get back to ya. u used teh top end of the 85 did u also use teh tensioner? That is self adjusting.

[skidoo99]

yes i used the 85 top end on the 87cooper lower. The tensioner between th two were different so I had to use the 85s on the top. Anyone know of any other differences?

[tri again]

yes i used the 85 top end on the 87cooper lower. The tensioner between th two were different so I had to use the 85s on the top. Anyone know of any other differences?

I guess you could check bikebandit since they have parts diagrams for each.
I want to know too, since I have some of each.
If it was mine?
actually i Had one with a 'tick' that made me sick from 50 yards.
Pulled the valve cover off and held a rag to the rocker arm and it STFU, thank god.

I guess there's a way to adjust the valves when the cam is NOT in the correct position.
Lobes want to be pointing UP.
I think mine got adjusted with the cam lobes pointing down so the clearance was huge.
TDC on the crank comes around twice as often as the cam so they say (not even sure about THAT) but
make sure both the cam and crank are where they should be.
Still thinking about the little one with leukemia from a previous post.
I DO hope it's something supersimple after all that work.

[skidoo99]

whats stfu?

[Headsup]

stfu means Shut the up. so when he held the rag there it didnt make the noise

[tri again]

stfu means Shut the up. so when he held the rag there it didnt make the noise

Thanks for the clarification.
Yeah, it was like a dream when it quit knocking/ticking when I
preloaded it with a rag.
I also notcied everything got shiney because of running it with the cover off.
Superfine oilmist drifted everywhere so be prepared.
PRETTY sure there's no chance of losing a finger with this UN approved procedure
but I got neurotic with mine (pristine 87) and counted exhaust pulses and determined it
may be in time with valve motion, and then pulled the cover, started it,
held the rocker with a rag,
gasped a prayer of thanks, adjusted the valves and have been in dreamland ever since.

Really hope it's a simple fix for you.

[dcreel]

whats stfu?

It's a close relative to GTFO, the official cousin to the SNAFU and friend of FUBAR

[Headsup]

Now thats just getting out of hand.. Lol I dont even know what SNAFU or FUBAR is lol

[dcreel]

[skidoo99]

haha thanks for the clarifications. ill try the rag on the rocker but i truly believe its coming from somewhere else. its a very loud knock, tick sound. i put a screwdrive up to the motor and listened through the end and it seems to be the loudest on the right side of the head where the chain is. you can actually hear a tick tick tick. has anyone ever had a problem with the sliders the chain runs in. thinking maybe they are loose enough they are allowing the chain to slap into the aluminum of they themselves are slapping back and forth. im willing to take it apart again cause this is bugging the hell out of me.

[tri again]

haha thanks for the clarifications. ill try the rag on the rocker but i truly believe its coming from somewhere else. its a very loud knock, tick sound. i put a screwdrive up to the motor and listened through the end and it seems to be the loudest on the right side of the head where the chain is. you can actually hear a tick tick tick. has anyone ever had a problem with the sliders the chain runs in. thinking maybe they are loose enough they are allowing the chain to slap into the aluminum of they themselves are slapping back and forth. im willing to take it apart again cause this is bugging the hell out of me.

I know that feeling.
It interferes with my sleep.
I see nuts and bolts whizzing around and picture caged rollers trying to escape too.

If it helps you sleep, go back thru it in your mind.
I doubt you left anything loose.
Did you even go near that stuff in the first place?

I'm supposed to tell you to double check everything to be safe and sure,

and probably shouldn't tell you that having worked on engines since before unleaded fuel,
I would've bet my tool box that my 250 knock/tap/click KNOCK!!
was a godbless'ed connecting rod or deadly critical wristpin.

I calmed a little, and counted the knocks to be in time with exhaust pulses.
I mean, it made me nauseous from 40 yards....sickening, disgusting, pristine 87 b red.
Someone had adjusted the valves with a rusted shovel or with the cam not at tdc,
I have NO idea, but that's what worked for me.

It would also suck to no end if it was something as simple as a chain guide rail that could come loose and ruin an otherwise perfect engine.

Hang in there. We're all right behind you.

[smvorndran]

Make sure you set the valves at .003", and not .030". .030" would make the rockers slap themselves silly.

[skidoo99]

yes i did set the rockers to .003. when the engine is running you can hear the rockers but also hear the louder ticking. i think im going to pull it and tear it down again. ive been using it but the noise is driving me insane. my neighbor actually came over and asked what was wrong when he heard me riding it. haha