Cam Chain Tensioner Checks on a 900

[Matlock]

Went out for a ride today, forgot to put my earplugs in and noticed a high pitched metallic rattle at about 4000 rpm under load and on the overrun. Could it be the auto cam chain tensioner? Can someone advise me how to check it is working OK please? The manual shows it removed from the bike for testing, but I'd rather not do anything this drastic just to check it, as I seem to remember someone on here had the timing chain slip when they took it out [img]style_emoticons/<#EMO_DIR#>/blink.gif[/img]

Cheers,
Chris.

[dapleb]

Be careful if you fiddle with it or you might "do a dandy". More info in linkydinks.

http://www.carpe-tdm.net/ipb/index.php?sho...mp;hl=cam+chain

http://www.carpe-tdm.net/ipb/index.php?sho...mp;hl=cam+chain

http://www.carpe-tdm.net/ipb/index.php?sho...mp;hl=cam+chain

[Gary]

I have the same problem and I have picked up a new tensioner to replace the old one with, £49.00 including gasket (part no. 5PS-12210-10 it has K070412A underneath in small font, gasket Part. no. 5JW-12213-00).

I'm going to fit it now and see what the deal is, hopefully I won't do a dandy 'cos I have to use it for work tomorrow [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]

EDIT: Went well no problems, seems to be ok but the commute will tell the tale [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

The new design tensioner body (as opposed to the finger bit) is about twice as long as the old one. Once the tensioner is out you can see that the finger actually seems to press on another plate, which I suspect the chain runs over. When I took mine out I was careful to note any movement of the chain or the plate and thankfully it stayed put. New one in and Allen bolts tight, remove the locking plate, finger pops out and the jobs a carrot.

[Matlock]

Thanks for that guys - but I'm still a trifle confused. Is it necessary to position the engine at TDC on cylinder #1 before removing the cam chain tensioner? Or can you just whip it out anywhere (if you'll pardon the expression).
Also, my bike has only done 12,000 miles, seems very low to be replacing the cam chain tensioner. What mileage is yours at Radio_am?

[Gary]

Mine is at 49,000 miles.

I don't think it's necessary to be at TDC but you could be unlucky I suppose. To be honest though, I think you'd have to be really unlucky for that to happen because there's 10 cam lobes so as one is coming on cam there's probably another just coming off cam and balancing it out.

From what I've gathered on Carpe, the early cam chain tensioners were badly designed and didn't put enough pressure on the chain making it slap. I don't think the mileage has much to do with it.

[dandywarhol]

NO NO NO NO NO...................DON'T EVEN THINK ABOUT TAKING THE TENSIONER OUT WITHOUT IT ON TDC LEFT CYLINDER!

If you did it otherwise radio you're one lucky SOB!

Even setting it on TDC wrong cylinder will have the inlet cam jump back 3 teeth - believe me I've done it.

Mine first rattled at around 15,000 miles. I still think Yamaha should be replacing them out of warranty - there's obviously a fault as they've changed the design as indicated by the -10 suffix number. It's a nonsense that a camchain tensioner only lasts 12,000 miles! [img]style_emoticons/<#EMO_DIR#>/ranting.gif[/img]

This post was last modified: 04-11-2007, 11:11 PM by dandywarhol.

[Gary]

Firstly Dandy, I completely agree that I seem to have got away with my ignorance four or maybe five times taking the tensioner out without setting any crank. I'd also suggest people do it your way!

However, I have a couple of questions to try and help me get my head around what I've gotten away with and one proviso of probably why I have gotten away with it.

I think I've gotten away with it because I've always done it on a cold bike, so it would just be the pressure of the buckets on the cams that would lead to any movement. Anyway, questions:

1: Why TDC on left only?
2: Why doesn't the chain jump a tooth when the cam chain is flapping about like a woman of the nights labia?

[dandywarhol]

1: Because that way the cams on number one cylinder are opposing each other keeping the chain taut. With the right cylinder on TDC firing the cams are facing each other and when you remove the tensioner - THWAAAAANG - the inlet cam jumps back 3 teeth.

2: The worn/fecked tensioner might let the chain slap but not enough movement to jump a tooth IMO. By the way, it's not necessarily wimmin of the nights labia which flap - wait til you see a prolapse..... [img]style_emoticons/<#EMO_DIR#>/blink.gif[/img]

This post was last modified: 05-11-2007, 11:35 PM by dandywarhol.

[robelst]

<!--quoteo(post=60266:date=Mon 5th Nov 2007, 01:11 PM:name=Radio_am)-->QUOTE(Radio_am @ Mon 5th Nov 2007, 01:11 PM) <{POST_SNAPBACK}><!--quotec-->1: Why TDC<b> on left only</b>?
2: Why doesn't the chain jump a tooth when the cam chain is flapping about like a woman of the nights labia?<!--QuoteEnd--><!--QuoteEEnd-->

1: If you can manage to position<b> <i>both </i></b>cylinders at TDC at the same time, a jumpy cam-chain will be the last thing to worry about [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] Iirc there is the least pressure on the cams in this position. I suspect on the older 360 degrees TDM it may make no difference whether you use left or right TDC but I've drunk too much wine to be sure about that.

2: The tensioner pushes against the chain-guide at the far side of the guide's rotation point. So when you remove the tensioner altogether you suddenly get a whole lot of additional slack in the chain, even compared to when the tensioner wouldn't lock itself correctly. What happens then is that the chain drops (almost) entirely from the teeth of its bottom drive and is at the mercy of the slightest movement caused by the valve-springs pressure.

You could be lucky, and you can of course manually turn the engine a few time afterwards to see if it rotates without locking but as I found out myself an engine can jump a few teeth and still seemingly run fine. It's like playing Russian roulette [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img]

[Gary]

Thanks guys, it all makes perfect sense.

Robelst, if it was a 360 degree crank I suspect both pistons would be at TDC [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img] I think you might mean 180 crank, all that wine must be making you see double degrees [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img]

Dandy.. I was just about to have dinner but I might leave it for a while. Thanks [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

[dandywarhol]

I'll let you tell 'im Robelst [img]style_emoticons/<#EMO_DIR#>/cool.gif[/img]

[Matlock]

Thanks for all the advice guys, I’m going to play safe and go with Dandy’s method, parts now on order. I like to know exactly what I’m doing before I get the spanners out, so I just want to confirm the plan. The bits I’m really not sure about (i.e. most of it [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] ) are in blue – your comments most welcome, as ever.

1. Seat, side panels & fuel tank off.
2. Remove the cylinder identification sensor.
3. <!--coloro:#0000FF--><!--/coloro-->Remove generator cover on LHS, or can I just remove the two inspection plugs to get at the centre nut and the timing mark?.<!--colorc-->
<!--/colorc-->
4. Remove spark plugs.
5. Turn engine (<!--coloro:#0000FF--><!--/coloro-->via nut at centre of generator which I guess must be direct on to crank?<!--colorc-->
<!--/colorc-->).
6. Put little finger down hole where cylinder identification sensor was onto the camshaft, turn crank anticlockwise until I feel a raised part on the exhaust cam approaching (<!--coloro:#0000FF--><!--/coloro-->this raised part looks like it has a square profile on the parts diagram, right at the end of the camshaft?<!--colorc-->
<!--/colorc-->).
7. Then turn the crank 1 FULL TURN anticlockwise from there and that's the left cylinder firing.
8. <!--coloro:#0000FF--><!--/coloro-->Do I still need to align the “T” mark on the generator rotor?<!--colorc-->
<!--/colorc-->
9. Swap the cam chain tensioner and gasket.
10. Start her up and check it.
11. Go to pub, drink real ale and feel smug.

I’ll take some pictures (cos I know we all lurve piccies) and do something for the knowledge base.

Thanks again,
Chris.

[dandywarhol]

I changed mine earlier on this year by doing this (no panels/tank off):

Removed 2 plugs from generator cover

Turned engine anticlockwise by the centre nut

Felt the compression as I turned it and the compression stopped just when the "T" mark aligned.

Rechecked by turning another 2 turns anticlock - compression is only felt before "T" when the left cylinder is on compression. [img]style_emoticons/<#EMO_DIR#>/good.gif[/img] If no compression is felt then you've got the left cylinder at The end of exhaust/beginning of induction -DO NOT REMOVE THE TENSIONER IN THIS POSITION

Removed and replaced the tensioner and refitted the 2 cover plugs.

Job done [img]style_emoticons/<#EMO_DIR#>/good.gif[/img]

[Gary]

<!--quoteo(post=60386:date=Tue 6th Nov 2007, 12:44 PM:name=Radio_am)-->QUOTE(Radio_am @ Tue 6th Nov 2007, 12:44 PM) <{POST_SNAPBACK}><!--quotec-->Thanks guys, it all makes perfect sense.

Robelst, if it was a 360 degree crank I suspect both pistons would be at TDC [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img] I think you might mean 180 crank, all that wine must be making you see double degrees [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img]

Dandy.. I was just about to have dinner but I might leave it for a while. Thanks [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]<!--QuoteEnd--><!--QuoteEEnd-->

Can anyone tell me? [img]style_emoticons/<#EMO_DIR#>/rolleyes.gif[/img]

Were both cylinders running with the same crank timing? Surely not?

[stuartsharp]

<!--quoteo(post=60540:date=Wed 7th Nov 2007, 01:40 PM:name=Radio_am)-->QUOTE(Radio_am @ Wed 7th Nov 2007, 01:40 PM) <{POST_SNAPBACK}><!--quotec-->Can anyone tell me? [img]style_emoticons/<#EMO_DIR#>/rolleyes.gif[/img]

Were both cylinders running with the same crank timing? Surely not?<!--QuoteEnd--><!--QuoteEEnd-->

What Robelst meant by 360 was the number of degrees the crank rotates between each cylinder firing. A 180 degree crank is used in a 4 cylinder engine (or a 2-stroke). [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img]

[ChrisG]

Boxer twins are also 180 degree too, both pistons hit TDC together, but in oposite directions obviously.

[Gary]

Check... Thanks lads [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

[Matlock]

<!--quoteo(post=60173:date=Sun 4th Nov 2007, 11:50 AM:name=Radio_am)-->QUOTE(Radio_am @ Sun 4th Nov 2007, 11:50 AM) <{POST_SNAPBACK}><!--quotec-->I have the same problem and I have picked up a new tensioner to replace the old one with, £49.00 including gasket (part no. 5PS-12210-10 it has K070412A underneath in small font, gasket Part. no. 5JW-12213-00).

I'm going to fit it now and see what the deal is, hopefully I won't do a dandy 'cos I have to use it for work tomorrow [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]

EDIT: Went well no problems, seems to be ok but the commute will tell the tale [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

The new design tensioner body (as opposed to the finger bit) is about twice as long as the old one. Once the tensioner is out you can see that the finger actually seems to press on another plate, which I suspect the chain runs over. When I took mine out I was careful to note any movement of the chain or the plate and thankfully it stayed put. New one in and Allen bolts tight, remove the locking plate, finger pops out and the jobs a carrot.<!--QuoteEnd--><!--QuoteEEnd-->
My new Cam Chain Tensioner turned up today - been waiting a bit for it - Fowlers said it was out of stock and had to come from Yamaha. Anyway, I've attached a couple of pics showing the exterior end of the tensioner. Am I right in thinking that once installed, I pull out the 'locking plate' with pliers and fit the end screw & washer? Job then becomes orange & pointy. [img]style_emoticons/<#EMO_DIR#>/good.gif[/img]




I'll do the job at the weekend and try & remember to take some pictures.

[dandywarhol]

Yep [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

[stuartsharp]

Matlock, while ya have yer camera out, could you please illustrate the difference between the old and new part, 'cos I wanna see whether my 05 bike has it or not. [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

Ta