Well There It Went...

[AmplexorJ]

Heading up a steep bridge doing 80mph and there goes the timing chain.
Having the damndest time getting the 10mm adapter to thread into holes to compression test before I get into the crankcase. If the heads are still ok then I hear that Im in for a helluva job.

Any tips or advice for this type of job overall?

[Motofool]

Originally Posted by AmplexorJ

..........and there goes the timing chain.

How do you know?

Check this thread:

http://www.ninjette.org/forums/showthread.php?t=118986

[AmplexorJ]

yeah I was actually reading it now lol and DL'd the vid series that was posted Thanks Tho

Im only assuming its the chain at this point given past exp. It could be something else but wont really know till I open it up soon as I run a compression test.

Of course if it is the chain I need to figure out why that broke.
It does have 23k on it.

[Motofool]

Originally Posted by AmplexorJ

.....It could be something else but wont really know till I open it up soon as I run a compression test.

I would open the cover of the head first.

If the chain is broken or has jumped, any compression test would give a wrong reading.

Cranking the engine for the test may cause more internal damage.

[AmplexorJ]

ok so I got around to the bike this morning and found that the cam chain jumped a few teeth on the intake cam. I assume its the tensioners fault?

So I reset the timing chain and the tensioner. chain felt tight everywhere.

So I threw a little oil in it and did a compression test. 139 & 143. seemed good enough to me.

Put it all back together and started it up.

Heres where it gets weird..... the bike immediately had a slight knock in the
heads and would die when I gave it gas. so I pulled the valve cover to see what was up and HOLY **** my oil was white.(the cam chain was still tight though and cams are still in position)

Pulled the drain plug and filter. probably a cup of water in the engine. WTF
pulled the plugs and there was a water droplet in between the contacts.
have no idea how water got in there. I think I may have left something open or uncovered while it was raining the other day

So now I dont know what to do other than change filter and oil a few times turning over the engine, drying plugs, clearing bowls.....

[Motofool]

Open the radiator and check if there is oil floating on the coolant.

Also check the coolant expansion tank (under the left side cover) for lost coolant.

If so, you may have a leaky head gasket.

Yes, the chain jumped because the tensioner failed.

Normally, the rockers break or the valves get bent or damaged by the pistons when something like this happens, but having compression is a good indication that the valves are OK.

[AmplexorJ]

ok after 6 oil changes and a little work the water issue is gone. I chalk it up to human error on my part.

So the bike sounds great at idle. starts right up and purrs. no noises whatsoever. however....

Give it gas to about 4k and up and I start hearing a rattle coming from the heads that increases as I throttle up.

same noise on a test ride around the block and felt like a serious loss of power after 4k in any gear. didnt go over 30 mph(didnt want to do more damage)


I doubt it would rev past 8k at full throttle.

All Rockers are intact and in place. decent and consistent compression. no noises at idle. timing has been set to specs and the cam chain is still tight.

[alex.s]

sounds like you did what i did... smoked a crank journal bearing

or maybe your timing is wrong

[AmplexorJ]

oh and its a higher toned rattle. not like a piston knocking

[alex.s]

did you measure the cam chain? maybe it's stretched beyond service limit

[AmplexorJ]

Originally Posted by alex.s

did you measure the cam chain? maybe it's stretched beyond service limit

no but I set the EX and IN cams at spec to 2T re-installed the chain w/33 pins from EX to IN reset tentioner and the chain is tight on all 3 sides. Ive checked it each time I test ran the bike in the last 2 days.

It shouldnt be stretched out of serv limit after 22k or so I hear. and if it were off by even 1 tooth wouldnt the engine idle a little rougher than usual? and this all happened stressing my bike going up a bridge at 80mph (im 6'4" 270lbs)

anyways. im scratching my head wondering WTF

[alex.s]

i doubt going up a hill caused it. my cam chain was 5mm over service limit at 25kmiles. don't assume anything especially after catastrophic failures.

i hate to say it but as far as i see, all signs point to a busted crank.

like you said if it was timing or compression, it would idle poorly. if it was a bent valve or a leaking ring you would be burning oil out of the exhaust. the tapping you hear doesn't come from nothing, something is hitting something... what would make something hit something when above 5k and not below 5k? what changes between there? how fast the pistons are going up and down... loose chains make a lot of noise at idle, same with clearance issues. too much clearance between the rod and the crank means once it passes a certain rpm, the moment of inertia will be strong enough to overpower the compression of the piston and the rod will bounce between the two sides of it's attachment to the crank making a sweet high pitched ticking noise (not like the low pitched thump of a piston hitting the top end)

[alex.s]

if you want, pulling the head off to check the pistons and cylinders and crank and rod is actually very easy... set to tdc 1, take off the water intake and the oil feed line on the head, take the valve cover off, take the cams and cam chain off, unscrew the 7 (9?) 6mm allen bolts. pull out the ex. side chain gaurd. the in. side chain gaurd is bolted to the bottom so you'll have to slide it through the head/cylinders as you take them off... after that you should be able to pull the head and cylinders up and off... there should be no vertical play on the rods... you'll also be able to check your piston rings/cylinder walls and your valves and the seats and all that

[Motofool]

Originally Posted by AmplexorJ

no but I set the EX and IN cams at spec to 2T re-installed the chain w/33 pins from EX to IN reset tentioner and the chain is tight on all 3 sides.

That is not sufficient to verify if the chain is worn out.

This writing explains some details about engine's noises:

http://www.supramania.com/forums/sho...gnosis-and-FAQ

If a bearing went bad, you may be able to find metal particles in the oil.

[AmplexorJ]

OK so if the chain is stretched... it could present the symptoms described?

Guess its time to split the case and measure that damn chain

[Motofool]

Oh no, don't need to split anything for measuring that chain, just uncover the head.

See how to do it:

http://www.ninjette.org/forums/showp...5&postcount=25

http://www.ninjette.org/forums/showp...2&postcount=27

[AmplexorJ]

WHa whats this you say? I thought I had to split the case to remove the chain and then measure.

[AmplexorJ]

nevermind. Im an idiot. I found it http://www.ninjette.org/forums/showthread.php?t=104334

[AmplexorJ]

So i measured the chain and it was ok... on one side.
The second section was at service limit and 2mm over service limit on the opposing side of the "good" section.

Changed the chain. (wasn't as hard as I thought it would be.) Now its running good again.

SOLD it for $1200 to a friend of mine.

THANKS GUYS for the advice and insight

[Motofool]

Originally Posted by AmplexorJ

Changed the chain. (wasn't as hard as I thought it would be.)

THANKS GUYS for the advice and insight

You are welcome.

Did you split the bottom of the engine?

[AmplexorJ]

I did. but only after I measured the chain.