282 replies to this topic

[Catteeclan]

Was it a new chain? Wondering if it has a tight spot or maybe something in the bottom that should be there.
Think I'd have that pump out of the way to watch the bottom while rotating.

[dablik]

Not new on the rebuild Dave, but PO told it was'nt long changed so i kept it, anyway i'll probably have to replace i think ? i'll need to drop the oil to remove pumps and if i'm going to do that may as well fit new while i'm at it because

 

Struggled on me own a bit this morning as madame decided to pressure was the front of the house    after setting the timing marks using the cam bolt holes had a look at the timing mark and it had moved anti-clockwise by about 10mm, rotation dropped a tooth on the exhaust but i expected that, reset, snuggled into place real easy while getting swmbo to hold the timing mark in place, replaced CCT, rotated and gained a tooth on the Inlet and dropped 1 on the exhaust, cupla more tries with swmbo at the helm, offset a tooth but same as before, last try sees the Inlet gain 2 teeth and the exhaust drop 1 tooth, piccie a bit askew.

 

Is it possible for a chain to be mullered enough to cause this much agro ?? Dont mind fitting a new one but not sure if this is only chain related or summit amiss with the valve train, i can hear the valves gaspin when turned over, cant say i've noticed that before...

[Catteeclan]

You've got to go into the bottom for piece of mind I think. New chain too if it was mine.
If you don't find something in there then there must be fault in the chain or bottom sprocket.
If the prob was up top I'd have thought you'd have spotted it by now. You could make sure that either pistons aren't at TDC and with the chain off rotate each cam just to make sure nothings locking. You'll feel resistance as each lobe pushes the valve down but should feel smooth doing so. Hope that makes sense.

This bugga is def testing you but you'll get there in the end.

Edit, thinking more on this, one cam moves after setting, then the other moves after setting, got to be something wrong on that chain.

Edited by Catteeclan, 29 May 2021 - 05:32 pm.

[dapleb]

So next move examine chain/sprocks/tensioner carefully?

Can you hear oubt jump/catch on rotation?

I'm trying to think of good news.....maybe once this conundrum is solved the fopping and parting will be solved!!!

[dablik]

You've got to go into the bottom for piece of mind I think. New chain too if it was mine.
If you don't find something in there then there must be fault in the chain or bottom sprocket.
If the prob was up top I'd have thought you'd have spotted it by now. You could make sure that either pistons aren't at TDC and with the chain off rotate each cam just to make sure nothings locking. You'll feel resistance as each lobe pushes the valve down but should feel smooth doing so. Hope that makes sense.

This bugga is def testing you but you'll get there in the end.

 

Okay and i'll order up a new chain, i hope to christ there's nowt wrong with the sprocket on the crank,  not sure to be honest if it feels as smooth as before, i mean even with plugs out you notice some resistance as it's coming up to TDC, just trying to think if i can rotate the cams 360 without the chain in- situ..

[dablik]

So next move examine chain/sprocks/tensioner carefully?

Can you hear oubt jump/catch on rotation?

I'm trying to think of good news.....maybe once this conundrum is solved the fopping and parting will be solved!!!

 

Already examined daps but best check again, CCT had a quick go in the ultrasonic cleaner, it ratchets nicely and does'nt jump, i tested it on every tooth to be sure, so CCT seems good, cant really noticed a physical jump, was watching closely as swmbo rotated crank, but summits moving, maybe camshaft sliding (can it do that).

 

Also measured the CCT before starting today, the amount extended was 19mm, full length extended is 23mm, so a difference of 4mm but dont know if that's significant..

[dablik]

Just to mention, i have no problem whipping the head off, but really as a last resort, cant notice anything  detrimental to the valves as it's turning okay but am wondering when i first had that whopping bang with the carbs on initially if it's possible to have bent a valve slightly !! or would this be very noticable while rotating the engine.. 

 

Edit, righto i'm doing some homework, for anyone interested, boogered chain symptoms explained proper..

 

Well that's an interesting write up, down the page it's mentioned a new chain set on the cams (assume no CCT) has about 3mm slack up and down, seem to recall mine was solid perhaps suggesting summit amiss, time to drop the oil and have a look see now..

Edited by dablik, 29 May 2021 - 06:50 pm.

[Studley Ramrod]

Some good info there Dabs. Saved to my favourites.

[dablik]

Yep a good site, dont know if the info should crossover to TDM but the difference in CCT length old chain v new gives food for thought as well, mine 19mm extended when set and 23mm max length ?

 

I remember you asking if the chain was okay when i 1st rebuilt, well it worked furra while anyway.

[Studley Ramrod]

Could well be the chain needs replacing going off the CCT measurements.

 

Be good to get some measurements of new chain v old wan iffin you decide to fit new.  I don't remember asking about the chain, your memory is obviously better than mine.

They're pretty easy to fit so no major mechanics involved, which is nice.  Only problem I remember having was trying to get the chain guide lower pin out, the wan you have to screw a bolt into to remove, was a right pain.  You shouldn't have any probs though.

[leehenty]

asking the obvious here but are you sure cam sprockets are tight to cams ? And that if sprockets removed the relationship of cam wheel marks to the cam position is correct ?

[dablik]

Defo going to fit new at this stage, seems the next logical step at this point, just trying to remember if i get the chain out with just the left oil pump removed, chain guide should'nt be an issue though, is it possible to leave the oil filter in. might get a drizzle out the pump if i do after dropping the oil..

 

Also see how the pistons lie before hand..

asking the obvious here but are you sure cam sprockets are tight to cams ? And that if sprockets removed the relationship of cam wheel marks to the cam position is correct ?

 

Cam sprockets not removed Lee. that would be a right bugger of a job, handled them today and not loose that i could tell, worth a check though.

[Studley Ramrod]

Defo going to fit new at this stage, seems the next logical step at this point, just trying to remember if i get the chain out with just the left oil pump removed, chain guide should'nt be an issue though, is it possible to leave the oil filter in. might get a drizzle out the pump if i do after dropping the oil..

 

Also see how the pistons lie before hand..

 

Cam sprockets not removed Lee. that would be a right bugger of a job, handled them today and not loose that i could tell, worth a check though.

I removed both oil pumps, think the camchain guide is bolted in there somewhere, but one pump might be enough, iirc the old chain comes out from the oil pump end and new goes in from there too.  Piece o string on old chain helps when feeding new chain upwards.

[dablik]

I removed both oil pumps, think the camchain guide is bolted in there somewhere, but one pump might be enough, iirc the old chain comes out from the oil pump end and new goes in from there too.  Piece o string on old chain helps when feeding new chain upwards.

 

Cam guide comes out left side but need pump removed anyhoo, i'll try and see before ordering, it's only to know if i'll need gaskets for both pumps as they are different.

[Dickiebig]

You could just split the chain and join new to old and feed through.
Ichy did that recently

[fixitsan]

I think if there was that much wear in the chain it would be in pieces.

My normal routine is to align the crank for TDC, then set the exhaust cam in the correct position so that there's no slack down the front of the chain between the crank and the exhaust cam, Then I cable tie the chain to the exhaust cam, and with all the slack on the inlet side and with the CCT out, get the inlet cam in the right place, and that will leave all the slack on the inlet side of the engine(to the rear), then pop the CCT in, or push a plunger into the CCT hole to take up the chain slack, to make sure it doesn't slip on the crank

 

You don't want to fully tension the chain before putting the cover on because the chain guide in the cover presses on the chain and increases the tension a little bit. I fit the CCT with the cover off, to check the timing position while turning the engine forwards, and when I come to bolt down the cover I slacken off the CCT bolts to relive the tension

 

The other issue is the inlet cam likes to jump because when in the setting position it's holding back spring pressure on one of the inlet valves which is depressed by one of the cam lobes, so you need to watch out for that jumping, again, as soon as you have it in place cable tie the chain to the sprocket.

 

Only turn the engine over in the running direction while setting up, or accept that you might have to start again if you try nudging it backwards after overshooting the TDC position, and this makes sure there is no slack on the front edge or between the cams

 

If you have any doubts about the TDC position it's usually quite reliable if you put a feeler down the bore and rock the crank, a paper straw is pretty safe for that job, you will be able to feel the TDC position when the straw stops rising and starts falling. Doing it this way has never failed to get the crank in the correct position, even when the chain was badly worn the cams were still easy enough to align in the best position.

 

I think your inlet cam is jumping, when your back is turned   or there is a bit of slack down the front side, because of the fact you're exactly 2 teeth out the chain is probably not stretched to a ridiculous amount IMHO

[dablik]

You could just split the chain and join new to old and feed through.
Ichy did that recently

 

oh the hassle on me knees of riveting a chain link, i wanna have a look at the bottom end and would really prefer to just dump the oil and remove the oil pump, i reckon less faffing about in the long run and gaskets are cheap, good thought though.

[dablik]

Cheers Chris it's pretty much exactly what i do, it was a pain previously but cant ever remember it being this chronic before, you may well be right that the chain still has life left innit but me minds made up and i'm changing it, from a cost perspective it's a mute point as i aint riding and a day out for me is generally 2 tanks at least and a weekend much more..plus lots of new parts on me bike and she's a keeper.

 

Interesting about the chain guide getting even more tension with the valve cover on, in fact i usually set it up without the chain guide and only put it back on when timed so will do so next time, also never slackened of the cct bolts to put the cover on, that would bug me probably not seeing what's going on 

 

Still want a look in the bottom and pull the chain guides for a look see for peace of mind really, i'm hoping with a new chain it will all fall into place like normal..

 

Both pistons parallel at TDC, only moved the crank back by 10ml without the cct in otherwise always anticlockwise..

Edited by dablik, 30 May 2021 - 06:18 pm.

[fixitsan]

Cheers Chris it's pretty much exactly what i do, it was a pain previously but cant ever remember it being this chronic before, you may well be right that the chain still has life left innit but me minds made up and i'm changing it, from a cost perspective it's a mute point as i aint riding and a day out for me is generally 2 tanks at least and a weekend much more..plus lots of new parts on me bike and she's a keeper.

 

Interesting about the chain guide getting even more tension with the valve cover on, in fact i usually set it up without the chain guide and only put it back on when timed so will do so next time, also never slackened of the cct bolts to put the cover on, that would bug me probably not seeing what's going on 

 

Still want a look in the bottom and pull the chain guides for a look see for peace of mind really, i'm hoping with a new chain it will all fall into place like normal..

 

Both pistons parallel at TDC, only moved the crank back by 10ml without the cct in otherwise always anticlockwise..

 

I only noticed the cover guide thing, after suffering a weird cam tension fault with a Kawa 550 i used to have, the guide is very pronounced, if you fit the cover after setting the chain tension you end up overtensioning it, and within 10,000 miles it gets loose again.

I can't say it is identical with the TDM, and it might not be an issue at all, but I saw the guide and just played it safe

 

Now I've just said all that I've just looked at some covers on the internet, and the guide int eh cover is much smaller than I recall, maybe there are different versions, but I think it's more likely my memory is tricking me. I'm sure if it was an issue someone else here would have mentioned it so maybe it never is such a problem with the TDM     (Once I figured oout my mistake with the Kawa 550 i went on an owners forum to mention it and got 'yeah we all know about that !'

 

I hope it's not your crank sprocket, but I think it's forged in the billet, which means it's very strong, usually anyway !

 

The chain is easy to swap, I though it was going to be a 'mare but it all went to plan, and it's a good chance to check the oil pumps anyway

[MickC]

I have only re read the first post,my MK2 was popin and farting cutting out hard to start no revs shooting up though and my starter rely was breaking up...literally falling apart.

Whats the relay got to do with the engine running....no feckin idea BUT there is a wire goes from the starter relay to the safety cut outs relay,may have had something to do with it,but when relay swapped over all was good.