Another noise thread: 1997 Marauder VZ800

**rainman** · 4th January 2009, 21:04

I started my bike up today to go for a pootle up to Puhoi, and as I have been on leave for a few days and have not been riding, it was properly cold. There was a mild knocking noise, which went away after it had warmed up. This was combined with misfiring once or twice - which may be unrelated. This has happened to me twice before over the past 12 months, but has gone away - the first time I replaced the plugs, the second time I confess I did nothing...

Given I'm on leave at the moment I now have a chance to look at this, but although I'm a halfway competent rider, I'm a mostly incompetent mechanic. That said, I'm keen to learn, and happy to give things a go, but know my skill and tool limits. The bike is a 97 Suzuki Marauder VZ800V, coming up on 45000 kms. Last serviced about 6 months/6000 kms ago, so probably due for at least an oil change RSN.

Power delivery is fine, there's no major smoke blowing out the pipes, and oil consumption is negligible. The noise is not noticeable under load even at low speed, nor when I started up to return from the pub.

I have read my service manual, plus the last umpteen pages of this forum, plus another US site, for anything to do with engine noises and have reached the following conclusions:

Noises are effectively impossible to diagnose over the Internet
Engine noises may be located by using a screwdriver/garden hose - I'll do this tomorrow
Engine noises are not to be ignored! Even intermittent ones.
Top end noises can be related to valve clearances, cam chain tensioners, or cam chains about to pack in (among many others no doubt)
Cam chains have a typical life of about 45000 kms
Cam chains slipping and/or breaking should be avoided at all costs as this buggers up your valves and pistons
It's probably within my capabilities to check/adjust the valve clearances, although apparently Marauders are particularly fiddly so I should budget many hours and maybe multiple attempts for a first time.
Cam chains/tensioners are further down in the service manual after the bit about using a crankcase separating tool, and other scary things, and V-Twin cam jobs may even be extra tricksy, so.. I'm thinking all cam chain/tensioner work is beyond my capabilities
In any event it looks like cam chain tensioners aren't really adjustable, the manual says check and if sticky replace.
....
Therefore I need a spannerman.

Can you knowledgable folks please confirm that my reasoning is correct? I don't want to shell out cash needlessly - there's a recession on - and will happily have a crack at fixing this if it's likely to deliver a result, but it seems given the age of the bike that finding a trustworthy and competent mechanic is probably the best option.

TIA

**ManDownUnder** · 4th January 2009, 21:14

Valves or tappets. Clearances are higer when they're cold (giving a clicking or tapping noise - possibly what you described as "knocking"?

After a longish rest maybe one of them's sticking? An exhaust valve sticking open a fraction would explain the backfire (ignited fuel escaping past the valve and down the pipe), and this would be aggrevated after a long break from riding when ALL the lubrication would have drained out of the head and away from the valves.

Can only guess but an easy test to narrow down the source is to use a screwdriver as a stethescope. Handle to the lobe covering the opening to your ear canal, and the tip of the screwdriver onto the suspected area of concern - where the noise is coming from. You'll hear it if it's there...

**rainman** · 4th January 2009, 21:35

Ta, I'll do the screwdriver test tomorrow and report back. Do you reckon it's worth me doing the valve clearances regardless of the likely condition of the cam chain? Would a cam chain on it's last legs make a noise all of the time or just while warming up?

I've attached a brief snippet of engine noise as at tonight, a bit lumpy as the bike had cooled down again and I didn't want to drown things out with a heap of choke. Note this is not a PDF file, it's an mp3 with a PDF extension... just right click and save with just the mp3 extension and you too can hear what my engine sounds like! I'll do the same tomorrow after she's properly cold.

**oldrider** · 4th January 2009, 22:20

Before you do expensive (maybe destructive) spanner work, do the simple things first.

You say you don't ride the bike very often or very far.

You have already recently had the bike serviced and changed the plugs.

What octain fuel do you put in it? (we get dished up some crap fuel and it does go off)

Drain the tank and put in fresh fuel of the recomended octain and go for a decent run.

When you have done all the simple easy to do stuff and the problem is still there, take it to a reliable service shop to get all the tuning checked.

If that fails then get a reliable trustworthy mechanic familiar with the brand to check it out. Good luck John.

PS: Didn't sound too bad to me but then again I am losing my hearing now!

**rainman** · 4th January 2009, 22:41

Originally Posted by oldrider

Before you do expensive (maybe destructive) spanner work, do the simple things first.

You say you don't ride the bike very often or very far.

You have already recently had the bike serviced and changed the plugs.

What octain fuel do you put in it? (we get dished up some crap fuel and it does go off)

Thanks John.

I ride the bike pretty much every day, commuting in to the city, 25kms each way. I've only had the noise three times now in the last 12 months. The service and plug change were a while back, it's been about 6000kms since the last oil change and I'll do another this week while I'm on leave, unless I get professional attention for the noise. Fuel is 91, as recommended in the manual, it was regularly from Mobil but for the last few months at least I've switched to Pak n Save so I can pay at the pump. I'm just worried the noise is a wonky cam chain that will break the bike if I don't get it done, and I think cam chain work is beyond me.

Originally Posted by oldrider

PS: Didn't sound too bad to me but then again I am losing my hearing now!

That's my concern too - my hearing isn't that flash either so I hope I'm hearing all the odd noises that are there, not missing any... But anyway that recording was this evening when the bike was a bit warmed up.