950 noisy engine

[hudson6161]

I have an 04 with 9800 miles...same noise, same amazingly fun ride...

[Gustavo.Ramos]

Rebuilt the oil pressure valve. The spring was a bit compressed, extended it to the 47mm's, checked the piston, no scoring and put everything back in. Started the engine.... major clatter! Laying the bike on it's side might have bleed the oil off the channels and air got in. It took a bit to quiet down. Still noisy as before, a bit shaky, tried to balance at 4k, but no visible improvements.

Have some pictures of the rebuilding, might do an animated gif file someday.

It looks like indeed is part of it's character being rattling all the time... if only we could find someone who knows what parts were changed to quiet it down...

going for a ride now..

[Dustodust]

my high mileage 04 motor rattled like crazy but I fixed it with a low miles 2007 engine out of a crashed bike , nice and quiet now

I have a theory that the noise could be coming from backlash in the cam gears but cant prove it cause i sold the old motor before I thought about it
I came up with the idea when I was replacing the head on my Toyota tacoma 4 cyl . the cam gears turn against each other (similar to the LC8) and it has shim and bucket valves. The toyota has a split spring loaded cam gear to take up the backlash noise and somehow it came unwound as I was assembling the cams. When I started it up it made a rattling sound like a 950. I preloaded the spring and the rattle went away

[Gustavo.Ramos]

Dustodust, what part in the schematic you are mentioning that *may* affect this clatter?

i'm up for some TLC.

thanks

[YOUNZ]

My guess, counter balance shaft issue!

[1stiski]

Originally Posted by Pantah

My 2004 gets real noisy from time to time. It has since new. My friend's does too. The older bikes would sometimes loose oil pressure in the hydraulic cam chain tensioners (I am told). Makes sense to me because it eventually goes quiet with higher revs, which suggests the pressure pumps back up again. It's fairly intermittant, but on a long trip can happen a couple timer per day. It can be particularly noisy when it is hot after stopping. Starting it up again can sound like it is coming apart.

It is so noisy that riding buddies have asked me why it's so rattley!

DITTO on mine too.. since new, It sure gets some looks when I start and the rattle can makes noise.. HA !

[Gustavo.Ramos]

Originally Posted by YOUNZ

My guess, counter balance shaft issue!

Haven't dig too much into the subject, but there aren't any (or close to none) metal chips in oil filter or magnet drain plug.

Isn't there a thread with valuable information on that too?

[KTMoto]

My '04 is not too loud on cold start up, but gets pretty bad when hot. I wear ear plugs. That seems to cut out all of the mechanical noise, but not the music of the Akras..

[YOUNZ]

Originally Posted by Gustavo.Ramos

Haven't dig too much into the subject, but there aren't any (or close to none) metal chips in oil filter or magnet drain plug.

Isn't there a thread with valuable information on that too?

Vibration/noise says the counter shaft is moving in ways it should not. Worn bearings, chain, tensioner?

[Dustodust]

Originally Posted by Gustavo.Ramos

Dustodust, what part in the schematic you are mentioning that *may* affect this clatter?

i'm up for some TLC.

thanks

I am talking gears 3,4 and 5 that drive the cam

gear #5 is driven by the cam chain , then the cam gears (3 and 4) turn off of of #5

if there is any backlash at all in these gears it could cause the rattle , as backlash at the gears could be transmitting intermittent slack at the cam chain as the cams speed up and slow down as they alternately load and release from the shim and bucket pressure,
and the gears could also be clinking against each other as the load releases at the cam lobes from the shim and buckets

my toyota motor made a very similar rattle when there was unintended backlash in the cam gears and a light bulb went off in my foggy brain and I immediatly thought of the noisy high mileage 04 950 motor

according to my theory , you could change the cam chains but the noise would still be there because the gear backlash would still be causing the cam chain to whip and also allowing the gear faces to slap each other

also according to my theory the cold oil will cushion the backlash in the gears, but when it gets warm and thinner the backlash would allow the gear slapping as the cams release from the shim and bucket loads
in other cases the noise could be worse at initial start up until the hydraulic cam chain adjusters fill up

[Dustodust]

I see a possible clue in the parts listing

between 2004 and 2007 the #8 "bearing bolt" where the needle bearing for the #5 timing gear rides, has been superceeded and upgraded
it is possinle that this could cause the backlash that I suspect ?

worth checking out

[Gustavo.Ramos]

Originally Posted by Dustodust

I see a possible clue in the parts listing

between 2004 and 2007 the #8 "bearing bolt" where the needle bearing for the #5 timing gear rides, has been superceeded and upgraded
it is possinle that this could cause the backlash that I suspect ?

worth checking out

Don't think so. #8 part is like an axle where a bearing is fitted. I suppose the backlash between gears that you mention would be affected if gear #5 moved a bit up to have the gears working closer.

I'm more inclined to the upgrade on this part might be related to material resistance to avoid premature wear.

Also, if the engine is running at constant speed the tension on these gears is also constant, thus it is not supposed to have any backlash noise.

The noise i'm referring is related to RPM's, does not sound like camchains. Camchain slack has a very distintive sound, moer like rattling. It's more of a clicking (guess work enter here) like the lobes of the camshafts hitting the valve shims.

However, i'll try to investigate that specific part superseed