GSXR750 noise

[FruitLooPs]

Hi guys,

My old 1987 oil boiler is giving me grief in spades, got ~80,000kms on the clock. Got it with lowish compression on cyl one, and intermittent 3/4cyl running.

Traced it down to leaking exhaust valve and remedied that, had good compression across the board after that, and some money later :bleh:

so once it was sorted, I stuck the head etc back on redid the valve clearance and bobs ya mothers brother, went like a cut cat and I was a happy chappy. :eek:

Now one week after this, I was letting a friend try the bike out and I pulled up next to him on moorhouse ave after going round the hills (on my other bike) and noticed a loud metallic pinging/grinding noise from the engine :oi-grr:

He said it was still running fine, powerwise etc not sure what was going on. So we got it home and it sounded terrible. Imagine like a stone has made its way into the inside of the frame and is rattling about - or the exhaust baffle was gone.


But it's neither, after checking those out i was getting a little worried - I rode it to my parents (5mins away) to show my dad a week or two later and noticed it was on 3cylinders once again :doh:


Drained oil, after pulling starter motor (got that refurbed as it had just died) and noticed a small trace amount of metal paste in the bottom of the oil - only a few mils and not concentrated, more spread thru the oil finely. :no:


Noise is def from down low in the bike, top end is fine - I pulled the rocker cover again to check the cam chain wasn't loose somehow and mashing about, it's not.


Big end bearings, clutch somehow eating itself? where should I begin gixxer gurus??

Exhaust and sump will be coming off at somepoint in the nearish future now i've got the starter back

[BigG]

Flick it off and buy a Yamaha. Just so happens I no some one got an R6 for sale.

[FruitLooPs]

Haha, rather stick with what i've got. At least by the end of this crap i'll have a known good engine. Nice bike though mate.

Any mechanical advice welcome guys :headbang:

[FilthyLuka]

metallic pinging... yeesh.

If you suspect its coming from down low the first place to start is to whip off the crank side covers and have a looksee. Might be big end... Take a look at the XS650 engine rattle thread on how to check your big end bearings without tearing apart your engine.

[marty]

that's the problem with tidying up the top end and not the bottom and at the same time.

a bearing is more ngunga ngunga ngunga.....

sounds more like oil pump disintegrating or wet clutch falling apart. pull it down and look - it won't get better by itself.

[FruitLooPs]

Oh yeah for sure guys, it'll be getting pulled down or at least not ridden until its fixed one way or another.

I might be able to get a recording of the sound, but that would require starting which im not super fond of. Might go see if i cant get partway thru getting the exhaust off or something tonight

I'll go check that 650 thread now, thanks guys!

[FruitLooPs]

Right well i've got my starter back in, checked compression on cyl.1

Seemed pretty good considering the it was cold so I don't think thats related. Noise was still there so I got a clip of it, I've got the mp3 and also video of it.

I'll attach the mp3 file as something thats allowed :bleh: just remove the .doc off the end of it or drag it into your player of choice.

Ideas?? Now the starter is back and i've satisfied myself for the cyl.1 I think i'll pull the sump off in the coming weekend. Anything that can lead me to the correct direction is appreciated though, if you've heard it before or similar I wanna know!

79832

[FruitLooPs]

For those who were wondering
I pulled the head, checked valves and not leaking. I then noticed that TDC for cylinder 1 was 0.5cm lower than for cyilnder 4 :eek: off with the jugs, no bearing play but a nicely bent rod instead. :Oi: :pinch: engines out the bike now, so i'll just have to find a replacement and see. Sump pickup had a freaking washer in it too, which was probably the rattle - god only knows how it made its way in..

[Squiggles]

but a nicely bent rod instead. :Oi: :pinch:

Ah well at least it wasnt poking out of the casings :shutup:

[xwhatsit]

Jaysus! How'd that happen? Somebody put an iron door-stop in the combustion chamber?

Can you just get a new con-rod, or do they have to be a matched set with multis?

[FruitLooPs]

Another gsxr enthusiast just happens to have a spare rod that I can get very cheap off him, and yes they are interchangeable.

Will need to resort bearings etc and I too wouldn't mind knowing how I managed to bend it. Hydrolocking would be the most common way, but I don't recall that happening and cyl.1 carb doesn't flood fuel anywhere. Will get new one and my other three crack tested.

[ElCoyote]

.

a bearing is more ngunga ngunga ngunga.....




I just love it when you talk dirty. Lol :bleh:

[jonbuoy]

It doesn't have a couple of valve dents in the top of it?

[FruitLooPs]

Nope, which was the first thing I was looking for since I'd just had the heads re-done for a leaking exhaust valve.


Doesn't look like its contacted since the head was put on with the new valves, and they seal just fine. The noise (and presumably the rod) started making the noise out during a ride around the port hills, by my friend - which wasn't very spirited either, I was tagging along on the RG150.

[tommorth]

bit strange was it pinging detonating etc?

[AllanB]

Those spare washers left over after a engine pull down are meant to be left in the jar - popping them in the oil filler hole does not count as 'fitting' them. :oi-grr:

[FruitLooPs]

bit strange was it pinging detonating etc?


nah mate nothing, plugs are on the blacker side of things. No signs of deterioration on the head, pistons or bore but i'll have a closer looksie at the pistons when i pull them off the rods. :no:


haha yes AllanB they are, strange all the parts I took off fit back on with no spares first time round.. drats. :pinch:

I've given the frame a good scrub down while waiting for the other rod(s) to turn up and have them inspected. :)

[FruitLooPs]

Well according to the gixxer forum thread I've created, some fellow with 'over 100 performance gsxr engine builds' to his name reckons with almost certainty the crank will be shot as well if it's hydrolocked in his experience.

:crazy: Time to consult some engine builders over here I think, see what I can see.

[FruitLooPs]

Thread resurrection! :lol:

Figure I might as well update this finally, well got it all dismantled got a good second hand rod and crack tested crank, rods & pistons okay and put it back together myself start of this year.

Has a different set of carbs now + jet kit and I *never* forget to turn the gas off if I stop even though the floats seem fine on this set, not doing that again!

Got maybe 3,000km's on it since putting it back together doesn't seem to do anything improper so I'm pleased with myself. :banana:

[robinm]

that the rod I send you worked out ok.

[FruitLooPs]

Not half as pleased as I am believe me mate :Punk: :done:

Thanks again!