PROJECT 900

Don't take the pith. :roll:

 

"THE ZERO COMP STAKES"

LATEST BETTING

1-HOLE IN PISTON----------6-4
2-BROKEN VALVE------------2-1
3-HEAD GASKET-------------5-2
4-STUCK RINGS-------------7-1
5-CRACKED HEAD-----------9-1
6-CRACKED BLOCK---------10-1

50-1 THE FIELD.

TOTE OPEN.

 

A honest bookie is hard to find.........

 

Warped exhaust valve.

 

Other than having more coke than a power station, I'm none the wiser. :?

 

Those cylinder walls don't even look that bad; you might have got off lucky. Probably nothing more than rusted/stuck rings.

 

Will pull the block this AM & carry out the normal tests.
Fitz, in the pic' above, 006, right side of the frame you can see one of the YICS ports, the hole is the size of a pin head.

 

That's it- - Those need to be drilled out !!
But really, is that about 2 MM ??

 

Yes 2mm would be about right, it does make you wonder how much effect they have.

 

Wow. They're bigger on the 550s. Very interesting.

 

First test results:
Piston skirt 68mm
Top & second ring end gap .020 (0.50mm) limit 1.0mm
Bores are unlined with no ridges.
Book says stock bore is 67mm, so this has been rebored to oversize 4, unless Len can tell me different.
Given the info' to date, what is the general prognosis guys ?

 

Well, 67mm is stock bore for the 853cc "900" engines, while 68.5mm is the standard bore for the 891cc "900" engines, which is what your bike should have, correct? (the 891cc version).


So 68.0mm would be a 4th oversize (wow!) for an 853cc engine, and not be possible for an 891cc engine, and gosh knows what else it might be if it's not one of those...........what size cc's are cast into the front of the jugs?


I think it's quite unusual to see an engine with a 4th oversize set of pistons in it.........I've never seen one.

 

I will go & see what is on the block, Len, but I'm begining to feel better. 8)

 

U have to remember Chacal that he measured the piston skirt not the bore. Although I haven't been into the parts nearly as much as you I have never seen somedody do a 4th bore even in the days of two stroke dirtbikes you when 1 and maybe 2 and got a sleeve put it.


I'd say time to buy a new book hehe..

 

It says 891 cm3, so we have a whole different scenario.
There must be a part of this manual that I havn't found.
What do you think, a hone & rings, perhaps?

 

As long as the piston to bore clearance is within spec, a hone and new rings will do it.

There should be a piston to bore clearance spec in your manual and it wouldn't be any different between the two engine sizes.

 

Found the right section of the book, now, Hillsy.
Piston clearance = 0.03-0.05mm. Limit 0.1mm
Would I need just standard rings?

 

wiz to answer that I would hone or have the cylinders honed then you will have to measure them and the pistons you are going to use. It just has to be we can't tell you the rings you need until everything is cleaned up and measured properly. Then it will be apparent by the measurements as to what you need.

 

Yep - what he said ^^^

 

I will re-use these pistons, they are well in spec'
How's this for a clunk test.

 

Urk. Also, way off topic but an interesting indicator of our "global economy" I have the exact same electronic dial caliper. The display and placement/color of the buttons are EXACTLY like mine except mine came in a black plastic case. Sold by a different company I'm sure, but sourced from the same Chinese manufacturer no doubt...

 

I'm an analog type of guy myself............

 

Wiz,

I have sent you a message re piston/piston ring sizes based on my experience.

We have 891cc bikes...when I re ringed mine I just got standard rings...even after a light hone they work perfectly. 4th Oversize could cause problems.

 

Wiz,

I have sent you a message re piston/piston ring sizes based on my experience.

We have 891cc bikes...when I re ringed mine I just got standard rings...even after a light hone they work perfectly. 4th Oversize could cause problems.

Any oversize rings will require tailoring to the piston. I think Rick might have a detailed posting here on fitting an oversized ring to a piston so that it sits neatly on the piston with appropriate gaps as per specs.

Let me know if you need further information.

Cheers.

 

So am I, I just bought an analogue multimeter & I had to ask Polock how to use it.

 

Make sure you zero it before each and every ohm test.........and also, if the internal battery is weak, they tend to read incorrectly.........

 

Some rust off the holding down bolts dropped into the crankcase when I was lifting off the block, what's the best way to make sure that it doen't cause a problem?

 

Tips for cleaning pistons, any?

 

Common issue rebuilding an old motor. Fill the crankcase up with cheap 10W or 20W motor oil by pouring it down on the crank/conn rods and flush it all clean; then drain the oil and replace with "real" oil before you start the motor. I don't like to use solvents in a bottom end because you can never be sure it's all out; and a thinner liquid can carry crud INTO places you don't want it.

Carb cleaner and a toothbrush for cleaning pistons. If the tops are all coked up, use a wooden or plastic scraper; you can use a tiny brass wire brush in your Dremel too but be careful around the ring grooves. Even a brass wire brush can "soften" (round off) the edges.

 

. . . and then polish the crowns and combustion chambers !!

Spring for the 3 angle valve job too. Course then you'll need to re-shim.

 

Inside the pistons is a number, in this case it's 8500, is this the date of manufacture, or just a coincidence?

 

No. That's the work of a Japanese Motorcycle Building Clairvoyant.

When they built that bike, the Clairvoyant had a vision of someone buying the bike to overhaul and restore ...

That 8500 is how much money the Person saw in the vision, that you'll spend before the project is completed!

 

Gee, thanks, Rick, you Jobs comforter. :cry:

 

We're all guilty!

When we need one Stainless, Metric, Phillips-head Screw to replace the one you'll find,upon your return, right where you put it, so as not to lose it while adding Brand New Fluid to the Master Cylinder, which you just bought, by heading-over to the Auto Parts Store to get, despite acknowledging to your wife that you heard her say dinner would be in ten minutes, head-off to the Hardware Store convinced you will be home within the ten-minute window, only to find your dinner already in the refrigerator, still warm and no cars in the driveway indicating the family has already left for the cinema leaving you home all alone with the motorcycle and the dog, looking at your watch trying to determine if you can get cleaned-up and to the theater in time to be with the family as you empty your pockets, only to find three stainless steel screws and a stubby screwdriver causing you to be distracted for long enough to lose the window of normalcy and have the deadline for when you must arrive at the theater in time to join the wife and kids for the move be blinking at you when you look at your watch to see how much time you have left after finding the missing screw that initiated the odyssey on top of the plastic cover of the coffee you didn't drink that you brought home from Duncan Donuts.

 

Dammit, Rick, sshhh. Let him find out if that's $8500USD or $8500AUD.

Don't worry Wiz; whatever you sink into a 900 it's 110% worth it. The movie will come out on DVD before Christmas anyway.

 

It might be YEN @ 0.010505 USD, then that would only be 93 bucks 8)

 

Did I miss something, Fitz, what movie?

 

yeah, so how does this work? if i bet 4 dollars ill win 6? (2 for 1, 5 for 2 etc...)

me to Wiz. i dont have ANY idea what Fitz and Ric are talking about...

 

You would win 6 bucks, Lt, but only if you get it right.
+1 with Rick & Fitz, I feel like I turned over 2 pages. :?

 

I think ist going to be an Oxidized Exhaust Valve face and Seat from being open for ages.

 

And I think you will win the dough.

 

Do you want to take to money now, Rick, or let it ride?
Picture #2 here's expediency for you Fitz, Coke can ring clamps.

 

When I rebuilt my Triumph some years back, I had bought some "real" ring compressors. After about three tries and a nicely gashed finger, I pitched 'em and used a couple of tuna-fish cans (twin, bigger pistons) with the top and bottom cut out and they worked better.

Give us some "after" pics before you reassemble the head just so everyone can see that even the worst motor has hope.

This poor 900 looks on the INSIDE like your Kawi looked on the outside. Urk.

 

Will do to the pics', I'm waiting for my honing tool to arrive, so I can't order new rings yet.
Got just 3 out of 8 bolts out of the carb boots, Rick might say don't undo the others, but I want to change out all the nuts & bolts on this bike, so there is no way I will leave these, even if the worst happens.

 

As Billy Crystal quipped in the Classic Cult Film: "The Princess Bride"

"This is not dead. Just 'Mostly dead.'"

"Waaay, Hive zeene mudge woice."

 

Carb boot bolts: of the 5 stuck, I managed to get 1 out with the blow lamp & candle wax method, 4 snapped, first one I drilled & easy out, broke the end off, hour later got the bit out, re-drilled it & broke the easy right off, bang went another hour, good job it wasn't one of the blind holes.
The ONLY way is to drill & re-tap.
I'm glad that is done.

 

Put some Neverseize on the new bolts wiz - same with your exhaust bolts (it's good stuff).

 

OK Hillsy, will do, I was going with the KY gel. :wink:

 

You can use KY on the carb / airbox boots to help install (.....you can....no joke... )

 

"The Princess Bride" - hilarious movie! So many good on-liners in it, and funny to look at the cast now in current roles and compare. ( at least those who are still alive)

Dave Fox - proud owner of 83 XJ900RK Seca serial #000117 (17th one!!)