Melted Piston or worse

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  • Grease Monkey
    Grease Monkey
    2 years ago
    Before you go chasing shadow's check out the oil schematic so you know how the scavenging and pressure circuits operate.
    Google will bring up some to look at if you don't have one as yet.
  • inmate
    inmate
    2 years ago
    Thanks Grease Monkey I'll have a look tonight and see 9fnincsn get my hands on one online. Is this covered in the FSM?

    Edit - have one now
  • paulybronco
    paulybronco
    2 years ago
    Any updates .......
  • inmate
    inmate
    2 years ago
    Paulybronco - have been flat out at work mate and had to work yesterday also. I'm only doing 8hrs today so I'll finally have time to look into it further. If this rain keeps up I might even go home early. Here's hoping. Will update here first as soon as I dive in.
  • Wideglider
    Wideglider
    2 years ago
    Quoting steelo on 02 Aug 2021 01:17 AM

    Thanks WG. If the weather is not fine enough for us to ride past impressing people socializing and drinking coffee outside, we don't ride over here.

    Did see that South Park episode- pretty damn funny!
  • inmate
    inmate
    2 years ago
    Finally had a couple hours spare today. Pulled the heads and barrels. Will open cam chest tomorrow and see what's going on in there. 

    I'll leave a couple pics for now and will have more to say once the cam chest is open. I'll check the runout while in there on that side


  • paulybronco
    paulybronco
    2 years ago
    Quoting inmate on 14 Aug 2021 08:09 AM

    Finally had a couple hours spare today. Pulled the heads and barrels. Will open cam chest tomorrow and see what's going on in there. 


    I'll leave a couple pics for now and will have more to say once the cam chest is open. I'll check the runout while in there on that side


    So no visible damage to crown of piston...or hole ? Looks like one pot is not happy with plenty of carbon build up compared to other. Please keep the updates coming
  • inmate
    inmate
    2 years ago
    Updating as I go.
  • robnicko
    robnicko
    2 years ago
    did the breather sys on that particular cyl head look ok or any glazing visible on the bore?
  • Krash Kinkade
    Krash Kinkade
    2 years ago
    Quoting inmate on 14 Aug 2021 11:46 PM

    Updating as I go.

    when I had a twin cam, with chain drive. Every time I checked the cam chain tensioner friction plate. it looked like that. but I went to S&S gear drive as was doing high km/s. but my motor was not stock, so valve seat pressure was higher than a stock motor.
    that is reasonable ( I have seen them worse ). The main reason I went S&S gear drive was, after replacing those friction plates, about a week after there was a noise, so checked the new friction plate assembly had fallen apart & I was lucky to find all the parts in cam chest & not in the motor. so went gear drive, I got the same grind cam set ( but made for gear drive, can't use a chain drive cam set with gear drive ! ) was problem free .
  • inmate
    inmate
    2 years ago
    Again.. have been flat out with work and life much like you good blokes. The weather is warmer which in turn means more beers and less shed time. Living in Brisbane QLD and just awaiting the next unfortunate lockdown. . 


    My front cylinder had this mark on it. Any ideas as to what it could be?

    In short - a fueling cam plate and oil pump on order. As to an s&s 107 kit come.tomorrow I'm told.. will try borrow a fueing dial gauge for crank runout otherwise use my one from work..id much rather rather fixed plate set up.
  • Jersey
    Jersey
    2 years ago
    Quoting inmate on 22 Aug 2021 10:19 AMedited: 22 Aug 2021 10:20 AM

    Again.. have been flat out with work and life much like you good blokes. The weather is warmer which in turn means more beers and less shed time. Living in Brisbane QLD and just awaiting the next unfortunate lockdown. . 



    My front cylinder had this mark on it. Any ideas as to what it could be?

    In short - a fueling cam plate and oil pump on order. As to an s&s 107 kit come.tomorrow I'm told.. will try borrow a fueing dial gauge for crank runout otherwise use my one from work..id much rather rather fixed plate set up.

    Did the bike ever sit for a long time without running?
    Unless my eyes are that bad what else could cause that cylinder pitting unless it was moisture ?
    Oil getting past rings would have carbonised the head ?
    A lot more knowledgeable blokes on here than me but.
    Interesting thread.
    Jersey
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