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tri spark

Discussion in 'Norton Commando Motorcycles (Classic)' started by colin davie, Oct 11, 2018.

  1. colin davie

    colin davie

    Joined:
    Jun 16, 2018
    Afternoon all
    Having fitted a new tri spark to my 850 mk 2a and set the timing to 29 degrees it seems lumpy at tickover and just above , what should the timing be at say 1000 rpm ,2000 rpm ,it was set at 4000 rpm ,
    i found when following the instructions on fitting the slots in the stator did not line up the same as the old tri spark unit , maybe nothing ?
    any thoughts on this ,
    Colin
     
  2. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Strobe it.

    Also,
    If you’re new to Commandos, remember the trigger goes backwards. Being more used to Triumphs, I forgot once and ended up ‘timing it’ massively retarded.

    Or perhaps it’s just me that’s massively retarded !
     
    MexicoMike likes this.
  3. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
  4. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    Some would say that anyone who owns an old Norton is massively retarded...regardless of what you do with the ignition! So it's not just you. :)

    As noted in the post LAB attached, you can't beat the OEM advance curve! I keep threatening to put the points/AAU back in but the Trispark has done well and is pretty close advance-wise.
     
    Last edited: Oct 11, 2018
    jimbo likes this.
  5. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    If you've used a timing light and are at 29 (s.b. 28) degrees at 4000rpm, I don't believe the Tri-Spare has anything to do with your issue.
    I don't understand what you're asking. Assuming you put in all new parts, the slots will lineup wherever needed for proper timing. If you tried to use the old Tri-Spark rotor with the new Tri-Spark stator - don't do that.

    Also, most Lucas rotors have a timing mark at TDC and another 180 degrees away at BDC. You must use the TDC mark.
     
  6. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 25, 2004
    The Powerarc seems to be something too. http://www.powerarc.com/ids/cdl2.html

    How do you inspect the AAU to be sure its OK, anything to look for?
     
  7. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    It’s a 40 or 50 year old seriously obsolete mechanical component that lives in a dry environment and has been attacked by a long line of well meaning but ignorant botchers.

    It will not be ‘OK’...!

    There are however, a host of cheap, modern, reliable EI units on the market. All of which are perfectly OK.

    Jus’ sayin’...
     
  8. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Whilst I’m also sure that Norton got the advance curve right, how many AAUs are ‘right’? There are so many ways in which worn components, weak springs, etc can affect it. Even when new I’d guess there was a big difference between OEM units due to tolerance issues.

    Even if it was perfect, I think we forget the maintence that goes into keeping a points system working optimally.

    IMHO, you’d have to be a serious OCD enthusiast to choose to run a points system on a machine intended for riding.

    I’m NOT saying it can’t be done, of course it can, but IMHO an EI system will work better, more often, with less maintenance.

    Thereby freeing up capacity for one of the other many areas of an old Norton that do require OCD enthusiasm !
     
  9. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    I cannot argue with any of that. As you said, there are plenty of modern EI units on the market and, of course, EI usually requires no maintenance once set. BUT I will say that after buying my Norton in 'o6, the biggest improvement in engine operation/performance/starting occurred when I removed the Boyer that was in the bike and replaced it with the OEM ignition parts.

    Yes, the original parts needed some serious cleaning and lubrication. But they worked so well that I had no intention of changing back to an EI. Yes, regular maintenance/cleaning/lubrication is required to keep the mechanicals functioning properly but, in the scheme of normal maintenance, I didn't consider it much of a chore. But it IS required!

    As you noted, if you don't maintain the mechanicals, the ignition parameters change. If the weights don't move freely in/out, the advance curve is wrong. A common problem is the weights not fully returning at low RPM due to wear from lack of lubricant. The usual indicator is a sudden 2000 RPM idle! :) Also, as the points wear, the timing changes. ;) So, yes, from a ease-of-use point of view there isn't anything good to be said for points/AAU nowadays. BUT, if the points/AAU get the timing curve right and the EI does not, the points/AAU are a better choice if you are looking for the most responsive performance (and can deal with the maintenance).


    No, I am NOT anti-EI. I totally agree with installing EI on the Norton as long as it duplicates the factory timing curve. That curve, (all in by 3000 RPM) BTW, is pretty much standard for any conventional (non computer-controlled) engine that operates in the same RPM range as the Norton motor.

    FWIW, I was concerned a few years back at the reports of TriSparks having problems due to heat so I was prepared for that to happen and go back to the points if it did but since the TS has worked perfectly for 10 years (this year...wow, where does the time go?), I figure it's proven itself.
     
  10. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Agreed !

    An added advantage of a good EI like the Tri Spark is it’s easy starting, anti kick back and idle control functions. I don’t know HOW these functions all work, I just know that they do!

    BTW, I have Tri Spark ignitions on all of my bikes for which Tri Spark make an ignition!

    We all have our favourites eh?!
     
  11. B+Bogus

    B+Bogus

    Joined:
    Jun 28, 2009
    I learned that the first thing to check is that the stator mark is actually telling the truth.
    Early Tri Spark units did seem to have a number of failures.
    New ones have been redesigned, but not sure what changed.
     
  12. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    Oops - forgot to address this in my previous message...

    Corrosion/rust between the weights/their mounting pin and/or hardened grease there will prevent the weights from moving freely. Obviously, missing or worn/stretched springs will cause timing errors and, coupled with sticky weights, usually hard starting because the timing won't be fully retarded. I would replace the springs with new ones when refurbishing the old parts. Some folks intentionally removed one spring to advance the timing more quickly and gain low/mid response so if you only find one spring don't be too surprised.

    One major problem that can occur is that lack of maintenance (lube) can cause a groove/notch to form in the advance plate which will then cause the weights to hang up at that spot. Some work with a small file and then smoothing with some 400 wet/dry paper will sort that out. The key is that the weights move freely back and forth with no hesitation/hanging up.

    Points/condenser are no issue - replacements are readily available HOWEVER, there are claims that current points and condensers are not up to the build quality of the originals. That's not hard for me to believe but in the two years I ran mine with OEM parts, between the time I removed the Boyer and installed the Trispark, I didn't see any problems with points or condensers.

    The usual electrical checks for good connections/good grounds are important to ensure proper ignition, whether OEM or EI.
     
  13. colin davie

    colin davie

    Joined:
    Jun 16, 2018
    just to clarify , the new stator replaced the old dead unit but as i said if you place the new stator on top of the old unit the slots do not line up together when lining up the "a" and "b" marks . they are half a slot out, also the rotor is the existing one , but it is just two magnets so what can be different there ? The issue i had was when as instructed you static time using the led indicator by turning it anti clockwise and then slowly turning clockwise until led lights , this did not work as the slot did not allow me to do this , i ended up moving the rotor back a touch , it was then strobed and timing was ok , it may be nothing but seemed odd at the time , the motor runs well apart from a bit low down lumpy,
    Colin
     
  14. kommando

    kommando

    Joined:
    May 7, 2005
    I would retune the idle and check the throttle slides for sync first.
     
  15. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    "Also, most Lucas rotors have a timing mark at TDC and another 180 degrees away at BDC. You must use the TDC mark."

    Well, in reality, they are both TDC marks; one for the left cylinder and one for the right. The points system requires/allows setting each cylinder individually. E-ignitions usually (always?) use wasted spark so you only time using the #1 cylinder.

    In theory, the points allow more precise setting of engine timing since you can set each cylinder though, in reality, that setting starts immediately changing with normal wear.
     
  16. Triton Thrasher

    Triton Thrasher

    Joined:
    Feb 10, 2009
    Alternator rotor marks?

    No. One mark is TDC on both cylinders; the other mark is BDC on both cylinders.

    In reality, there is no individual cylinder timing advantage with points. Both pistons are at 28 degrees BTDC at the same time.
     
  17. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    Nope - think it through. The pistons go up and down together. The marks are 180 degrees apart so one is TDC and the other is BDC. If you use the BDC, then the timing will be 90 degrees off since the camshaft turns once for every two crankshaft turns.
     
  18. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 25, 2004
    The best running , starting 850 I owned was a low mileage example with stock ignition. Why cant the electronic ignitions available reproduce the stock curve? Powerarc's have a programmable feature , could you program it to reproduce that curve?

    http://www.powerarc.com/ids/cdl2.html
    Can be programmed with standard Windows PC with optional ECP (Program Link Cable)
     
  19. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
     
  20. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    You are absolutely right - don't know what I was thinking about...:(