B12 camchainy noises and limit of stock tensioner

[Shill]

Hi all,

General question on top end noise. I'm getting quite a rattle on my mk2 1200, mainly noticeable if you give it a small amount of revs in neutral. It's not a harsh knock, just a general rushing chatter that sounds to my ear like camchain, and a same kind of whirring when you're on the move. Also getting quite an angry rattle from somewhere at about 2k revs, but this passes as you rev past it, I reckon might be just something loose resonating at that speed so might be a red herring. Annoying around town though.

Anyway, the stock tensioner is pretty much fully extended, I think it had like 2 notches left when I refitted it a month or so ago, and gave it a gentle poke when I put it back in to help the spring. Definitely quieter now but still noisier than I'm happy with (my only reference for 'normal' is the original 750 engine I took out of it about 3 years ago, so memory is hazy and that had less miles on).

I've already picked up a manual CCT off eblag which I think has more travel on it... but question is am I daft to ignore it and  just try to take up the slack? I really don't want to do a chain replacement right now if I can avoid it. Going to re-check valve clearances too - I'm off on a Scotland trip next week so keen to have peace of mind for that. Thing is when it's moving it's hardly noticeable, performance is great, so I dunno if I'm just overreacting. I guess a 20 year old engine isn't going to sound like new. Maybe I just need to ride it for 2000 miles and chill out 

Edit: Reading that back I'm thinking 'yeah... that's what engines sound like'. But the tensioner question is legit!

Edited April 26, 2023 by Shill

[TonyGee]

they are generally noisy engines, out of the 6 ive owned only 2 where quiet. 

[Shill]

That's good to know - I should get myself to an event see what the others oil boilers sound like. When I had the top end apart last year everything looked pretty much fine and within tolerance. I'll fit the manual tensioner and keep an eye on it, maybe save my effort for when something actually needs fixing!

[wraith]

The cam chain tensioner spring go weak and you'd be surprised how much different they make, new spring is about £10 

[george 1100]

If you are at the limit of your tensioner then your chain is operating beyond the manufacturers spec

Edited April 27, 2023 by george 1100

[fatblokeonbandit]

1 hour ago, george 1100 said:

If you are at the limit of your tensioner then your chain is operating beyond the manufactures spec

hes right you know

[Dezza]

Camchainy is a great new word

[Upshotknothole]

Any idea how many miles are on the engine. 

[wraith]

Mist that bit of the tensioner at limit. 

New cam chain or/and blades needed

[Shill]

Cheers all for the input! I took out the old tensioner and it still had a few notches on it, so replaced it with the manual but happy with it for now. Good thing for my learning was putting the manual in there and being able to back it off a bit, hear the chain rattle come in and then tighten it back up. Upshot is the thing I was hearing seems to be something else around the front end just resonating at around 2k, I've checked everything it could reasonably be mechanically, rechecked the valve clearances, and suspect it's just something around the instrument cluster, mudguard or something. Got new exhaust gaskets and sealed up the connector box joint with liberal amounts of exhaust sealant. Hard to find the sound when it's not moving. I did about 150 miles up to Yorkshire yesterday, everything seems good, and setting off tomorrow on a trip up to Skye, across to the Cairngorms, then back down over the course of a week, should be about 1500 miles all in. Going with a mate on a 675 Street Triple, I'm glad to have the B12 lump for the motorways  Think I'm just paranoid about noises.

I think the engine is about 55-60k, but history is a bit of an unknown. When I did the top end last year, one cylinder was at the wide end of the tolerance on front-back direction, but not outside of it. I think mechanically it's sounding fine. Just smokes a bit out the breather when it's hot, which I guess is related to that cylinder. Will re-check things at the end of the year and maybe do camchain then. If it ever needs a rebore I guess that's a chance to big!

Is there much of a downside to using a replacement with a rivet link vs doing a full stripdown with an endless chain? I've riveted a drive chain before, I guess cam chain is essentially the same process just smaller and more fiddly?

Pic because everyone likes pics. Warning, contains one non-Suzuki.

[Gixer1460]

Double fiddly with the Hyvo chain - I've done rivets with a normal chain, not sure about a hyvo!

[TonyGee]

yes Hyvo's are fun !!!!!  I have a little splitter for them which has a small pin. the fun bit is putting the very small plates in when you are working on the head, the big danger is to drop a plate down the cam chain tunnel !!!!!!  use a shit load of rags in every hole just in case  

[Captain Chaos]

20 hours ago, Shill said:

doing a full stripdown with an endless chain

full stripdown is not needed.

Remove engine, remove rocker cover and camshafts, turn engine upside down.

Remove bottom crankcase half, remove crankshaft, swap camchain, rebuild in reverse order.

No new headgasket needed, no base gasket, no fighting the piston rings on reassembly.

[Shill]

On 5/2/2023 at 5:38 PM, Captain Chaos said:

full stripdown is not needed.

Remove engine, remove rocker cover and camshafts, turn engine upside down.

Remove bottom crankcase half, remove crankshaft, swap camchain, rebuild in reverse order.

No new headgasket needed, no base gasket, no fighting the piston rings on reassembly.

Awesome, thanks CC will bear that in mind. Trip went without a hitch, got back to the midlands yesterday, probably closer to 2000 miles all in. Bike pulled well all the way, used a bit of oil but no problems. We were really lucky with weather and the roads up in the North West are as good as they said they are