Author The End Of The Road or a new beginning . . . . . .  (Read 39074 times)

0 Members and 8 Guests are viewing this topic.

  • Offline Javaman   gb

    • Tiger Master  ‐    279
    • ****
    • Topic Author
    • #110

    Offline Javaman

    • Tiger Master
    • ****
    • Topic Author
    • Posts: 279
    • Why Do Today What Will Wait Until Tomorrow?
    • Bike/Model: 2008 Tiger 1050
    • City / Town: Sleaford
    • Country: gb
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #110 on: 29 November, 2023, 06:19:31 pm
    29 November, 2023, 06:19:31 pm
    I spent last week removing all the valves, labelling  and bagging them, along with their associated retention collets, valve springs and upper retention plates. I then set about cleaning up all the carbon in the cylinder head and from the exhaust ports.
    It was about this time that I started to query why I had so much carbon and in particular on the piston crowns. I did wonder if E10 played a part in all of this and whether or not fuels containing alcohol have a tendency to cause greater carbon deposits. Google helped put that theory to bed but there was no denying . . .the engine had more carbon build-up than it should but not only that, a lot of it was shale-like and loose but also, the deposits were inconsistent. At least one of the exhaust ports had no carbon in an area where the other two were encrusted . . . hmm!!!
    My next port of call with Google had me researching the cause of carbon deposits under valve seats and it would seem that the most common cause is due to burning engine oil, most often as a result of worn valve guides. In this instance, the evidence is normally clear to see and results in carbon on the valve stems and around the throat of the valve - absent in my case but of course . . . . there remains another and rather more obvious cause of oil consumption with the 1050 . . . cracked pistons!! I have never been troubled by oil consumption on my bike but I don't do many miles and it's always possible that I simply haven't noticed or perhaps the problem has just become worse more recently?
    Anyway - burning oil is the most common cause of carbon deposits in an otherwise correctly fueled engine but  . . . what really caught my eye was the statement that incorrectly seated exhaust valves are then subject to pitting and melting of the interface which can result in microspheres of molten metal eroding from the valve seats.  I looked at mine more closely . . . indeed, under a high-powered loupe. What I found is not confidence inspiring. . . . . .

    1. Earlier on in this post I posed a question about whether or not valves are "coated". One of the reasons I did so was because I had polished the head of one of my exhaust valves and was surprised to find it had a surface texture, much like fine sandpaper. When I looked closely, the valve head was black from carbon but punctuated by a great many minute raised metallic particles embedded in the surface - only now visible as metallic having been debrided by metal polish. The appearance was like weld spatter but was easily removed with a 3M scouring pad.
    2. I decided to look at the exhaust valves more closely and as the number 6 had the worst leak, took a look at the back face of the valve. In addition to the discrete carbon deposits, it has numerous small pits in the surface all around the circumference of the seat . . . not really noticeable to the naked eye but clear to see with a powerful loupe . . . . buggerations - this is starting to make sense!!
    3. Next I looked at the valve inserts in the head - all look normal to the naked eye but again, a magnifying loupe tells a different story. The inlets are all as per factory - you can still see the machining marks in the metal but having removed the carbon from the exhausts, the seats have numerous small pits and pock marks.

    If the metal on the valve faces comes from here, it's hard to understand how. Surely if the valve is leaking on the combustion stroke, any escaping high speed gases would squeeze through and rapidly travel down the exhaust, taking any molten microspheres with them and not  deposit them on the face of the valve within the combustion chamber???  I'm puzzled but prior to pulling the pistons, the following is my latest theory

    My pistons are cracked and this likely coincides with me first noticing a long cranking cycle required on engine start about two years and around 6000 miles ago - I've just lived with it ever since.
    This has caused oil to get into the combustion chambers and the deposition of shale-like carbon deposits which in turn, have caused incomplete closure of some of the exhaust valves. This has resulted in pitting of the valve seats - of the valve itself and the inserts in the head, plus the deposition of minute molten metal particles on the faces of the exhaust valves. Do note that nowhere else are these particles evident - not on the inlets valves or within the combustion chamber itself . . .all very odd.

    This has been bugging me and I decided that I would look more closely today at the "scoring" in my liners.  I did state previously that it was "minimal" and couldn't be felt with a fingernail - more like wear lines. . . .I was wrong. Mostly, they are as stated but one or two do actually register with a fingernail.

    It is all conjecture at this moment in time but of course, we will know soon enough. I had psychologically prepared myself to foot the bill for new liners and pistons. 900 isn't cheap but I'm attached to the bike and want to keep it. If that bill now morphs into 900 for pistons and liners, 600 for a set of valves, 1300 for a new cylinder head plus another 500 for incidentals (cylinder head gasket, valve stem seals etc etc), then clearly the economics don't stack up. In fairness, I don't need them to stack up but in this instance, the disparity will be too great to justify and I suspect there will be some great Tiger parts coming up on eBay in the not too distant future.
    I'll sit it out for now . . . . pistons will be out next week and then I'll know for sure but for now at least, I think despondent is the best description of my mood.

    Wear marks apparently insignificant but in hindsight . . . .




     . . . maybe not - one or two can be felt with the Mk1 fingernail!! 


  • Offline ZuluTiger   us

    • Tiger Supporter
    • Tiger God  ‐    3147
    • *
      #111

    Offline ZuluTiger

    • Tiger Supporter
    • Tiger God
    • *
    • Posts: 3147
    • KTM 1190 Adv back in the fold...
    • Bike/Model: Tiger 1050 ABS
    • City / Town: Suwanee, GA
    • Country: us
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #111 on: 29 November, 2023, 07:04:05 pm
    29 November, 2023, 07:04:05 pm
    Hey Jav, thanks for the update. I was wondering if you'd made progress. I think we have to wait for the liners to be pulled to really know what gives. The vertical scoring is certainly not good news but don't rule out a simple case of broken rings rather than pistons. I've had rings fail and break up due to one cycle of overheating and subsequent softening. I don't know that you have to give up on the valves and seats if the source of the metal is from a bad piston. If the guides and valves are okay, they may have a lot of life in them yet, once lapped in and cleaned up, with new stem seals. I wish Hamlin would chime in and comment at this point but probably would also want to wait and see the piston and ring integrity too. Don't get too despondent yet, it's till a fine project and entertaining us mightily. We could do a crowd funding sally to help if it's going to create a good story for posterity! Keep the old chin up Sir!

  • Offline Freddy   au

    • Tiger God  ‐    1484
    • *****
      #112

    Offline Freddy

    • Tiger God
    • *****
    • Posts: 1484
    • West Aus
    • City / Town: West Aus
    • Country: au
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #112 on: 29 November, 2023, 11:40:45 pm
    29 November, 2023, 11:40:45 pm
    You should've pulled the liners right out here & then JM - 15 seconds for each one and that would've have told the whole story. 

    Anyhow, regarding the head & valves - you're getting 'too deep and meaning full' and over doing the matter, if I may be so blunt.  Take the head, valves, springs, caps, collets, etc and new valve stem seal to a cyl head recon shop to do the reassemble & test job for much less than you're worrying about.

    Ethanol makes a mess on the valves - well documented by Hamlin.

    In the mean time -  :031:
    The best substitute for brains is ........what?

  • Offline dave_a   us

    • Tiger Pro  ‐    135
    • ***
      #113

    Offline dave_a

    • Tiger Pro
    • ***
    • Posts: 135
    • Bike/Model: 2007 Tiger 1050
    • City / Town: Fernandina Beach
    • Country: us
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #113 on: 30 November, 2023, 12:26:27 am
    30 November, 2023, 12:26:27 am
    I know enough to be dangerous. But vertical scratches usually indicate dirt entering the combustion chamber. I would ask if this bike used aftermarket filters or if the owner ever found a filter edge misalignment on a routine maintenance? God help us all if its a K&N air filter!
    The good news is it could just be worn out rings. I don't know what "unobtanium" the liners are made of. But if it's harder than the pistons, we need accurate and thorough measurements of clearances including ring lands as well as skirt & end gap. Better carefully check intake guide to stem clearances too. Dirt gets to them too.
    From what I see in the pic's, oil's not coming down the intake guides. But oil is going out the exhaust.
    Captain Obvious says its getting past rings. Lets pull it apart and find some measuring tools.

  • Offline ZuluTiger   us

    • Tiger Supporter
    • Tiger God  ‐    3147
    • *
      #114

    Offline ZuluTiger

    • Tiger Supporter
    • Tiger God
    • *
    • Posts: 3147
    • KTM 1190 Adv back in the fold...
    • Bike/Model: Tiger 1050 ABS
    • City / Town: Suwanee, GA
    • Country: us
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #114 on: 02 December, 2023, 02:58:20 pm
    02 December, 2023, 02:58:20 pm
    C'Mon Jav, lets hear it! Pull them liners and end the suspense...

  • Offline Javaman   gb

    • Tiger Master  ‐    279
    • ****
    • Topic Author
    • #115

    Offline Javaman

    • Tiger Master
    • ****
    • Topic Author
    • Posts: 279
    • Why Do Today What Will Wait Until Tomorrow?
    • Bike/Model: 2008 Tiger 1050
    • City / Town: Sleaford
    • Country: gb
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #115 on: 05 December, 2023, 10:46:04 pm
    05 December, 2023, 10:46:04 pm
    Finally, I spent a couple of hours yesterday and the best part of today removing first the liners and then the pistons.
    I was nervous of any broken piston parts falling into the engine and so I placed it on several old pillows front down on the floor and with the cylinders pointing slightly downwards. I inserted some foam sheet between the liners and crankcase to prevent piston contact as the liner was removed and contrary to the manual, I removed the liners with the piston at TDC and not BDC. Again, this was nothing more than a nod to the possibility of bits of junk falling off the pistons. The liners came away without a problem and withdrawing them from the block was a non-event. I labelled each, cleaned them in a little paraffin and made a token effort to remove most of the silicone sealant.
    I was very impressed with how clean they were and unlike others I've seen, not even a hint of corrosion - A testament perhaps to Honda's Type 2 Coolant which I've had in the bike since new with one change back in 2015.
    I cranked the engine until the no3 piston was at TDC and set about removing the inboard circlip. There's a small cut-out in one place around the groove and this allows the insertion of a small probe so that the clip can be levered out. I'm reluctant to use screwdrivers or indeed, any metal tools which might cause scratching and I found a cutdown lollipop stick worked just fine. Prior to levering out the circlip, it is very important to first push the gudgeon pin pack so that it is hard up against the clip in the other side of the piston. If you fail to do this, you will never lever the clip out as the gudgeon pin itself will restrict the clearance.
    Incidentally, the open end of each circlip is positioned about 20 degrees from the cut-out in each case and I suspect this is important to remember when reinstalling. If you reinstalled the clips with their open ends opposite the cut-out, I suspect it would be virtually impossible to remove them without first rotating them around in their grooves. Given the difficult access, this might not be possible either and so something to remember for future reference!!!
    The next problem I had was how on earth to apply pressure to the opposite end of the gudgeon pin in order to push it through. I spent 10 minutes scratching my head until I realised that I could simply turn the piston on its side and gain access through the side of the skirt. Even so, it turned out to be something of a problem - the circlip must have left a small witness mark in the side of the piston because try as I might, I couldn't push the pin through and out of the other side - partly due to limited access and partly my puny finger force. I was able to move it back and forth a couple of millimetres and eventually, I was able to push it through beyond the circlip groove and then still further by inserting a small socket into the far end. Once I had the technique, the other pistons followed suit without too much difficulty.
    I degreased with paraffin and brake cleaner before labelling each.
    Inspection revealed some scoring on the exhaust face of the No1 piston and corresponding scoring in the bore of the liner . . . this was the scoring I mentioned previously and which can "just" be felt with a fingernail. There was barely any wear anywhere else on either of the remaining pistons or liners. I will take advice as to whether or not the No1 piston and liner is reusable but at this stage, I'm tempted to simply replace all the rings and the No1 piston and liner in addition to any head work that is required. I won't do anything until I've taken advice on all of it and will then report back.
    Luckily for me, I have a local Triumph Guru who has been very helpful in the past and hopefully, he will give me an appropriate steer if I take the parts and show him what I'm dealing with.

    So . . .the question's been answered - all the theories came to nowt and none of the pistons are cracked. Indeed, apart from the one area of scoring, they're in fine condition. The question remains then as to why the engine developed carbon deposits sufficient to contaminate the valve seats and cause the loss of compression.

    Sheet foam inserted between liners and crankcase prior to turning the engine onto its front to facilitate removing the liners and hopefully prevent any broken pieces of piston from dropping into the engine.



    All set . . . attaching the liner puller tool to the No.1 liner and . . . .




    Out she comes . . . no issues!!




    This is the No.1 liner as removed. Note the complete lack of corrosion. A testimony perhaps to the effectiveness of Honda Type 2 Coolant?




    Removing the puller from the No.2 liner prior to teasing it out by hand  and moving on to the No.3 liner



    With the liners now gone, it was time to turn my attention to the pistons. I started with the No.3 and was immediately confronted by the problem of how to remove the circlip and then push the gudgeon pin through from the camchain side of the crankcase - there appeared to be insufficient clearance . . . . .




    I soon realised that all I had to do was turn the piston on its side and gain access through the recess in the skirt - still tight but doable!!



    The circlip turned out to be quite simple to remove with a piece of cut down lollipop stick but subject to the following . . . . .
    Ensure the gudgeon pin is pushed in as far as possible so that it is not pressed up against the circlip. This prevents the clip from being tightly retained and allows sufficient clearance around it so that it can be pulled free. Also, note the open ends of the circlip are perhaps 20 degrees or so away from the pry hole . . . it must go back like this. If the open ends are installed on the opposite side for example, then prying the circlip out will be nigh on impossible as the free end will not be released. As installed in the photo, levering at the hole allows the free end to be pulled clear and the clip removed




    With the liners and pistons labelled and degreased, they appear in remarkably good condition. Note the score marks on the No.1 piston on the far right - corresponding scoring exists on the liner.



    All that remains to do for now is to remove the silicone and general detritus within the crankcase and reinstall the liners as a temporary home whilst  I decide on the next course of action



    Last Edit: 05 December, 2023, 10:55:25 pm by Javaman

  • Offline Javaman   gb

    • Tiger Master  ‐    279
    • ****
    • Topic Author
    • #116

    Offline Javaman

    • Tiger Master
    • ****
    • Topic Author
    • Posts: 279
    • Why Do Today What Will Wait Until Tomorrow?
    • Bike/Model: 2008 Tiger 1050
    • City / Town: Sleaford
    • Country: gb
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #116 on: 05 December, 2023, 11:20:12 pm
    05 December, 2023, 11:20:12 pm
    As a footnote and given how wrong I was about my pistons being cracked,  I can't resist tempting fate and have conjured up a potentially plausible theory for the slow crank and how poor compression might cause it.
    If we assume an engine which is cranking on the starter but not actually firing. Furthermore, assume zero frictional, heat or any other form of losses . . . in other words, a somewhat hypothetical model . . . . .
    Consider each cycle in turn - suck, squeeze, bang and blow
     1. On the induction stroke the starter motor is drawing the piston down and in so doing, acting against atmospheric pressure and doing work by effectively sucking in the induction fuel/air mix through the inlet valve. Give this an arbitrary work value of 1 unit
    2. We now move on to the compression stroke and assume all valves are fully seated. The starter is now having to do a lot of work to compress the induction gases at a 12:1 compression ratio . . . . give this an arbitrary work value of 2 units.
    3. Now we move on to the bang cycle but the engine isn't firing and only cranking on the starter. Assuming 100% efficiency and with no losses etc . . .all the work done in 2. above is given back to the system and so work done is effectively -2
    4. Now with the piston at BDC, we are beginning the blow cycle - the exhaust port opens and the starter is driving the piston and causing the cylinder air to be expelled through the exhaust port. This is effectively the same as the induction cycle when cranking and the work load is the same . . .give it a work value of 1 unit.

    The overall work done by the starter is 2 units of work

    Now consider the same cycle but with leaking exhaust valves . . . . .

    1. The induction cycle will remain more or less the same . . . you could say adopt a work value of slightly less than 1 unit as a modest amount of air will be drawn in via the leaking exhaust valves but this will be tiny compared to the open inlet. Let's say 0.9 Units of work
    2. The compression stroke will be akin to pumping up a bicycle tyre - as you operate the piston, most of the air is escaping but does so under pressure. You are having to do a fair bit of work to compress the pump but when you get to the end of this stroke, there is no compressed air remaining . . . it has all leaked out. Clearly the work done is less than if the valves were fully sealing but more than if they were fully open . . . in other words, between 1 & 2 - let's call it 1.5 units then.
    3. Now then . . . this is where it gets interesting. The bang cycle is going to start with no stored energy from compressed air and given the valves are all closed but leaking, the starter is going to be forced to do work in order to draw  the piston back down . . . . another 1.5 then
    4. Now at BDC and the valves open for the exhaust stroke and the work done is 1 unit as the exhaust valves will be fully open

    OK . . so now tot up the amount of work done by the starter when cranking an engine with leaking valves . . . . 4.9 units!!!

    So, based on this fag packet approximation of reality, it would appear that at the very least, it is reasonable to conclude that cranking an engine with leaky valves requires more work than cranking one with properly seating valves?? 
    Am I missing something??  Perhaps the logic is flawed but I really want to put it to the test and investigate if I can get the engine rebuilt.
    Incidentally and I didn't mention this before . . . On the few occasions my bike has been slow-cranking, if I allowed it to fire up and idle for no more than 10 seconds or so before then stopping the engine and firing it up again, it would always crank at full speed. Previously I put this down to the bores being oiled and there being a reduction in friction, even though the engine run would be as short as only 5-10 seconds.
    Could it be that my valves were leaking on the cold crank but sealing again after a few seconds with the engine running??
    I'm clutching at straws here but never say never!!!!!
    Last Edit: 05 December, 2023, 11:26:12 pm by Javaman

  • Offline Freddy   au

    • Tiger God  ‐    1484
    • *****
      #117

    Offline Freddy

    • Tiger God
    • *****
    • Posts: 1484
    • West Aus
    • City / Town: West Aus
    • Country: au
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #117 on: 06 December, 2023, 12:09:08 am
    06 December, 2023, 12:09:08 am
    The question remains then as to why the engine developed carbon deposits sufficient to contaminate the valve seats and cause the loss of compression.

    From ethanol and a leaking valve stem seal or 3.

    Could it be that my valves were leaking on the cold crank but sealing again after a few seconds with the engine running??  Yes - that happened to Paul82's bike, but that was unrelated to any of the other problems he had with it.

    As for the slow cranking - it remains something of a mystery.

    The pistons look good to go again after the carbon from the ring groves has been removed.  As for the liners, I'd give them a hone with a 3-legged hone fitted with fine stones, ensuring the cross-hatch pattern was applied.  This is done by adjusting the hone to be fairly tight in the liner (wrapped in rags & tape and held gently in a vice) and using a variable speed drill on slow speed while pushing the hone in and out those few inches.  The hone needs to be so tight that the drill will almost not turn until pushed in & out rapidly about a dozen times, wiped out, inspected and repeated if necessary until the blemished area shows hone marks.  Cleaning the bore after honing is critical and done with oily rags.  When you think its clean do it with oily white rag until no grey disclouration is on the rag.

    Othrs will have input.

    This topic popped up on another forum overnight.  I have a 1995 Thunderbird 900.

    https://www.triumphrat.net/threads/cheap-way-to-remover-cyinder-liners-on-tb-900cc.1006302/#post-2004407105
    The best substitute for brains is ........what?

  • Offline ZuluTiger   us

    • Tiger Supporter
    • Tiger God  ‐    3147
    • *
      #118

    Offline ZuluTiger

    • Tiger Supporter
    • Tiger God
    • *
    • Posts: 3147
    • KTM 1190 Adv back in the fold...
    • Bike/Model: Tiger 1050 ABS
    • City / Town: Suwanee, GA
    • Country: us
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #118 on: 06 December, 2023, 12:20:27 am
    06 December, 2023, 12:20:27 am
    I'm going to put my money on the valves having nothing whatsoever to do with the slow crank. I've dealt with many leaky valves in different situations and nothing like that ever occurred. Less compression always made for easier cranking. I am not surprised that you've found nothing of major import in the cylinders as it never seemed to be the correct diagnosis, IMHO. I'm assuming you did a forensic review of the rings and verified good condition. This leaves you with a head that needs reconditioning and then a search for that slow crank, sorry. I have an opinion but will resist any armchair predictions. Just review the basics and I think you'll find it. Good work on the how-to and pics. Good luck with the rebuild!

    Be conservative with the hone. It is easy to overdo and end up with damage. Just break the glaze and provide a new bed for the new rings, nothing more.
    Last Edit: 06 December, 2023, 12:22:24 am by ZuluTiger

  • Offline dave_a   us

    • Tiger Pro  ‐    135
    • ***
      #119

    Offline dave_a

    • Tiger Pro
    • ***
    • Posts: 135
    • Bike/Model: 2007 Tiger 1050
    • City / Town: Fernandina Beach
    • Country: us
    Re: The End Of The Road or a new beginning . . . . . .
    Reply #119 on: 06 December, 2023, 02:09:30 am
    06 December, 2023, 02:09:30 am
    Let's quit dicking around.
    What's the ring end gap on #1 & #2 rings (and in the other cylinders)?
    What's the piston skirt to cylinder clearance?
    Know anyone with a bore gauge, Java?

    Validate the mechanical.
    Then you know it's not causative. This is the fun part: science!
    Dave