Valve tapping and backfiring

[robelst]

<!--quoteo(post=23692:date=Sun 3rd Dec 2006, 10:18 PM:name=dandywarhol)-->QUOTE(dandywarhol @ Sun 3rd Dec 2006, 10:18 PM) <{POST_SNAPBACK}><!--quotec-->Before you remove the tensioner it is imperative the timing is set to TDc on cylinder 1 (left hand) otherwise the timing chain will jump I found out the hard way by setting it up on cylinder 2 <!--QuoteEnd--><!--QuoteEEnd-->
I am not sure what / how it could jump if refitting the tensioner "pre-loaded" (or does a cam kind of turn around when no longer under pressure, potentially skipping a tooth or sumthin?). I will turn the crank a few times manually anyway to see if anything blocks before firing up. I have revived the Africa Twin again for travelling to work on, so I am tempted now to bite the bullet and change the chain / check timing and valves etc now that the TDM is halfway taken apart; I mean, that 1 click extra tension probably won't do much anyway, at least not for long, and I want to check the TPS too which doesn't seem accesible with the carbs still on the engine.

BTW: After working on the horribly inaccessible V-twin of the Africa Twin I'd hoped the TDM parallel twin would be a doddle to work. I must say I am rather disappointed Still, it could always be worse hey?

[dapleb]

<!--quoteo(post=23712:date=Mon 4th Dec 2006, 09:22 AM:name=robelst)-->QUOTE(robelst @ Mon 4th Dec 2006, 09:22 AM) <{POST_SNAPBACK}><!--quotec-->(or does a cam kind of turn around when no longer under pressure, potentially skipping a tooth or sumthin?).<!--QuoteEnd--><!--QuoteEEnd-->

EXACTLY.

[Histamiini]

<!--quoteo(post=22619:date=Wed 22nd Nov 2006, 11:32 PM:name=robelst)-->QUOTE(robelst @ Wed 22nd Nov 2006, 11:32 PM) <{POST_SNAPBACK}><!--quotec-->Roit, I think on my TDM it's definitely the cam chain rattling and not so much the valves: The noise clearly comes from the right-hand side of the engine where the chain runs. It's also quieter when cold (oil still thick), while valves are usually are at their noisiest when cold (clearance is biggest).
I see there's a cam-chain spanner (bolts on the outside), does that need inspection or is it replacement only? Or does it simply need a new chain (seems a bit early at 33k)? Or is it just a matter of "they all do that sir"?
I am not overly worried, it's just that the rest of the bike runs so incredibly smooth; this engine is truly something special, being such a big twin.<!--QuoteEnd--><!--QuoteEEnd-->

I have never really listened to TDM engines other than my own but it sure is noisy. When I bought it it had done about 35000 km, so the valve clearances had never been checked. There was a clear ticking noise coming from somewhere in the valve gear. Clearances on the exhaust valves were a bit small but adjusting them didn't change the noise at all.
At around 70000 km I rebuilt the top end becouse of high oil consumption. I also changed the cam chain hoping it would cure the ticking/rattling noise. Even with a new cam chain it still sounds the same.
I think the spanner is pretty fool-proof design, can't see how it could fail. If I were you I'd check the valve clearances anyway and while at it remove the tensioner just to see if it moves freely and the spring isn't broken.
So based on my experience I don't think the noise is anything to worry about. Mine has been ticking for 60000km and it's still going strong. The clutch is getting noisier though, I guess there's play in the clutch springs and they rattle back and forth.

[Tarmac]

<!--quoteo(post=23946:date=Wed 6th Dec 2006, 04:47 PM:name=Stink-Foot)-->QUOTE(Stink-Foot @ Wed 6th Dec 2006, 04:47 PM) <{POST_SNAPBACK}><!--quotec-->I have never really listened to TDM engines other than my own but it sure is noisy. When I bought it it had done about 35000 km, so the valve clearances had never been checked. There was a clear ticking noise coming from somewhere in the valve gear. Clearances on the exhaust valves were a bit small but adjusting them didn't change the noise at all.
At around 70000 km I rebuilt the top end becouse of high oil consumption. I also changed the cam chain hoping it would cure the ticking/rattling noise. Even with a new cam chain it still sounds the same.
I think the spanner is pretty fool-proof design, can't see how it could fail. If I were you I'd check the valve clearances anyway and while at it remove the tensioner just to see if it moves freely and the spring isn't broken.
So based on my experience I don't think the noise is anything to worry about. Mine has been ticking for 60000km and it's still going strong. The clutch is getting noisier though, I guess there's play in the clutch springs and they rattle back and forth.<!--QuoteEnd--><!--QuoteEEnd-->

It's comforting to know that I'm not the only one with a noisy top end! Definitely goint get eff-off noisy cans, that will cure it completely! Not even going to check clearances until 40k-km not arsed now. . . . .<i>TDM's. 'oh, they all do that'</i>

[tdm-in-weymouth]

<!--quoteo(post=23112:date=Tue 28th Nov 2006, 03:45 PM:name=Ashton Masher)-->QUOTE(Ashton Masher @ Tue 28th Nov 2006, 03:45 PM) <{POST_SNAPBACK}><!--quotec-->Mine ticks as well, started at about 7000 miles and has gotten prgressively worse, on 13000 miles now. I haven't had any back firing or trouble starting so I don't think it's the clearances and the noise does get worse when the engine is warm, but I am told <b>'they all do that'</b>.

I changed the cam chain tensioner (£45) easy to do, but still no better. (If ticking sounds are coming from the right side it's probably this.) I am starting to think that the cam chain itself is the source of the noise. Earplugs cure the problem completely!

It's driving me crackers though and I'm on the point of taking it to aYamaha Dealer for an opinion! <!--QuoteEnd--><!--QuoteEEnd-->


Did the tappets which were easy on a MK2 - due to tapping - still got a slight misfire at 70 - any ideas would be appreciated - have seen emulsion tubes mentioned but don't know what they are - supposedly in carbs?

Andy

[dandywarhol]

<!--quoteo(post=24197:date=Mon 11th Dec 2006, 02:26 PM:name=tdm-in-weymouth)-->QUOTE(tdm-in-weymouth @ Mon 11th Dec 2006, 02:26 PM) <{POST_SNAPBACK}><!--quotec-->Did the tappets which were easy on a MK2 - due to tapping - <!--coloro:#FF0000--><!--/coloro-->still got a slight misfire at 70<!--colorc-->
<!--/colorc--> - any ideas would be appreciated - have seen emulsion tubes mentioned but don't know what they are - supposedly in carbs?

Andy <!--QuoteEnd--><!--QuoteEEnd-->

They are in the carbs Andy......info HERE, click "Mikuni VL1500"

When I get to your age I'll probably have a slight misfire too..................

[Guest]

<!--quoteo(post=24203:date=Mon 11th Dec 2006, 02:44 PM:name=dandywarhol)-->QUOTE(dandywarhol @ Mon 11th Dec 2006, 02:44 PM) <{POST_SNAPBACK}><!--quotec-->When I get to your age I'll probably have a slight misfire too.................. <!--QuoteEnd--><!--QuoteEEnd-->
Only 2 years to go, eh wee man?