Kawasaki Sportsbike Riders Club - Australia - Online Forum

My fecking little 250 threw me another left hook (yeah, you weren't kidding about "just when you think you have it sorted" Gos!!) by leaking past the head gasket. However i am unsure if it is a problem with the head being warped, or if it was just me screwing the install up and possibly forgetting to pinch up a bolt to spec.

As it stands i've taken it apart (unfortunately I've gotten good at this, total teardown to having the head sitting in my hand was 70 minutes, tops), i need to clean the old gasket goop off the head and measure the head for any sign of twisting and then get it skimmed to suit if required. To be honest, thinking about it, from the score marks i've seen on the head from when i first took it apart, i suspect that there's a fair chance the deck needs to be skimmed..

If it comes to what i fear has happened, does anyone know of a good place in sydney that i can take the head (or maybe the barrels if that's the problem) to, to have it skimmed to spec?

Kings cross

z900/zx9 wrote:Kings cross

nah mate, you go there for porting and polishing...

machining is a whole different kettle of fish. maybe wait till sexpo is in town

Mike I have used Rams based in windsor many times & they do a really good job including porting honing etc
http://www.ramsheadservice.com.au
Highly reccomend them

+ 1 - it was a few years ago and it was a car head, but they were straight with me and saved me $$$$$.

Maybe ask Daisy where she found her Hed Mechanic

Mike take it to peak re-bores in barry ave peakhurst if u have any prob getting in touch let me know

i second mike's comment... everybody needs a good hed polish every once in a while...

Cheers for the suggestions guys, will clean the head and barrel up and see where i'm at & let you know. I was initially trying to word this so i could avoid the whole *snigger*head*snigger* laughs, but then thought cbf, they're big enough as it is.

As for the head itself, i couldn't fit the 0.04mm (thinnest feeler guage i have) between the ruler and the head, *ANYWHERE* no matter which way i measured it, diagonal or straight across without forcing it between the two. So from the sounds of it the head is very much true.

I then went on to measure the top of the barrel for trueness as well. It turns out that the barrel is 0.07mm depressed towards the centre (cam chain well), however aside from being insufficiently tightned together (one headbolt was well and truely too loose, hence i suspect i bodged the tightening) there's no reason why there was any leak between the barrel & the head. Also as the engine was leaking out through the area with "zero gap" my bet is plainly placed on my screwing up when i installed the head gasket (a lesson learned for when i re-reassemble this sucker).

Ok, some progress here.
It turns out i miss-read the manual as there were a few torque settings with similar descriptions. I used the loading for the incorrect bolt on the head, so did 8-10ft/lb instead of the 18-20ft/lb i should have with the head studs.

The fly in the ointment is when i was doing what i thought would be the final bit of tightening, one of the bolts decided to deform on me and break. I eventually got it out by pounding the crap out of it, the use of a butane torch and by a nifty new product called "Loctite freeze and release" to get the bolt out. Next up is using 2-3 nuts screwed against each other to force the remaining studs out of the motor & put the ones on order in asap.

Oh and a handy hint to anyone that uses this stuff, it needs way way way more than 30 minutes i gave it from the time you spray it to using anything with a flame near it. I got a lovely "WOOF" & a good foot of orange blue flame out of the crankcase, & scared the hell out of myself in the process.

( I was a skeptic, but that stuff actually works, it uses the principle that the compressed gas in the can has a significantly lower temperature when sprayed to shock freeze bolts to - a fair few degrees and hopefully releases them from a seriously stuck position)

thanks for the tip on the loctite product didnt know about this one

This is the last update in these threads from me as i consider this chapter in the headache of my little bastard bike closed.
Heads were good, no machining required,
Head stud SNAPPED on re-tensioning the head retaining nuts due to age, replacements obtained for all 8. Head hurridly re put o barrels, checked valve lash, bit loose, but within spec.
Started her up, managed to forget to nip tight one of the valve space adjusting nuts and heard the sound of someone smacking the case with a hammer, followed by a metallic smacking sound that later made sense when i discovered said adjuster and locknut were absent from the right hand inner valve assembly.
Much fartarsing around ensued (including the offending bits jamming the timing chain solid at one point) before the adjuster was removed looking worse for wear. The nut was flushed to the bottom of the strainer with me cycling the old engine oil through the casing at least a half dozen times. So it's not going anywhere.

Reassembled the timing & what not triple and quadruple checking everything was done correctly, and then checking again for good measure. Engine runs pretty well, slightly poor power at the top end, which i discovered when i took a trip home from work today and the bastard wouldnt start with a dead battery.

Now i've got charging/rectifier issues to sort. A pain in the arse, but a shitload less fucking about than the mechanical hell this bike has put me through previously.

Thusly this thread endeth here, i'll get the lucas wannabe electrics working pretty damned soon, what's the bet its a corroded connection putting this show on hold.

so much for the "last update". Turns out nothing is wrong with the electrics, the alternator or any ancillary equipment. It just turns out that with the new rings and when at a fairly high operating temperature the engine (and particuarly the rings) have expanded so much that the starter just doesn't have quite the grunt to turn her over, once the engine was cold again she turned over without a problem and started again! This issue should go away within the next couple hundred km or so.

Good to hear you got it sorted Mike..... now make the most of the higher compression you have at the moment it wont last long