Gen 1 engine rebuild

Discussion in 'VBoost Room' started by huw s, Sep 30, 2019.

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  1. Sep 30, 2019 #1

    huw s

    huw s

    huw s

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    Hi all, newbie here. I have a Canadian import, triked with a sprung back end. The paperwork I got with it indicated it had been treated to all kinds of goodies - upgraded alternator, Barnett clutch, stage 1 jets, crankase vent kit, don't recall what else. It also mentioned a replacement, and then a rebuilt engine.
    Whatever, it had a holed/broken piston when I bought it. I did speak to the so called expert who did the work on it, he was suitably vague and defensive.
    Stripdown revealed:- No goodies, low spec engine, serious meltown and liner wear in one, some wear and water damage in another and two good liners and pistons. The gearbox looks good, crank is good, all rods have survived. I haven't stripped the oil pump yet, but did find 3 pins/rollers that look as if they could be drive pins loose in the sump - still trying to work out what these are if anyone can help - they are 20mm by 2.5mm approx.
    I toyed with replacing the engine, but without finding one with history I was a bit loath. So, I have bought a used crank case, some good used pistons, and intend to do some mating. The liners are out of the case, honed and look good. The pistons and rings look like they will be happy in there. Next job is to heat the case and bang the two liners in. The issue I will have is I will need to top the block to bring everything back flush, and flycutting ally and cast together isn't my favourite job.
    Pics? Yes, if I can, once things start coming together.
    One question, if I may - if this engine is a replacement, low spec, (3uf) if I recall, do I need to do anything special - rods, cams, valves Any different?
    Edit to say - I pulled the top off one carb - it had full power slides - no restrictors, the power valves are fitted, and there is a lot of evidence of modifying (plugged hole in the slide), ham fisted bodgery - hex head cover screws with at least one stripped thread, many of the phillips float bowl screws butchered, ditto the rack mountings, and the sync of the butterfies is visibly way out, as is the enrichment.
    Tomorrow I will attempt to unscrew the head studs out of the scrap cover, knock in a pair of liners and jig it up for a flycutting test.
     
    Last edited: Sep 30, 2019
  2. Oct 1, 2019 #2

    Julian Tomkins

    Julian Tomkins

    Julian Tomkins

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    wow, can't help with any info but good luck with it
     
  3. Oct 1, 2019 #3

    one2dmax

    one2dmax

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    Need to post up some pics. The liners should be in place before any honing (or boring) is done because they will have slight distortion occur when they are in place. You're likely going to be ok but that's not typical engine etiquette.

    The rods/pistons, cams and misc are all more or less the same. You can post pics and I can review them to make sure.

    You should not need to deck the block if the sleeves are full seated unless you are getting new sleeves. You can if you want but keep it to a bare minimum. When you alter the deck height you change the fitment of the intake and exhaust components.
     
  4. Oct 1, 2019 #4

    huw s

    huw s

    huw s

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    Thanks, appreciate one of the named guru's taking the time to respond to a newbie. I must admit I am asking myself why I didn't just buy some new pistons and bore and hone the block. Never mind - too late now.
    The replacement liners are 7 to 9 thou taller in the top hat measurement - meaning they will stand proud by that amount - I can't see it going any other way.
    On the carbs issue - is the number marked on the needle? And how many and what size holes should be in the bottom of the slides?
    Thanks,
    Huw
     
  5. Oct 1, 2019 #5

    one2dmax

    one2dmax

    one2dmax

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    The needles will be stamped with a 4 digit (sometimes 5) number and letter code. Post up pics.
     

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  6. Oct 2, 2019 #6

    sdt354

    sdt354

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    An unexpected side benefit of using the stage 7 needles, including increased top end and mid range power, was some very good mpg.
     
  7. Oct 2, 2019 #7

    huw s

    huw s

    huw s

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    Thanks for that Sean. Looks like I have the No5 needle, so at the moment to the best of my knowledge I have full power carbs. I will get to checking jets later.
     
  8. Oct 3, 2019 #8

    one2dmax

    one2dmax

    one2dmax

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    The stage one are junk and far too often people get sucked into believing that they are the best ones out there for mild or stock bikes with stock or slip-on mufflers.
     
  9. Oct 4, 2019 #9

    huw s

    huw s

    huw s

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    Oops, my mistake, the ones I have are No4 in the list.
     
  10. Oct 5, 2019 #10

    huw s

    huw s

    huw s

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    Engine rebuild on stop for a few days - wifes dragging me off to Cyprus and 2 days ago while making a jig to mount the top case in my miller the inverter drive died. Be 3 weeks till I know if it's fixable.
    In the meantime I bought some used front pegs and mounts, including brake lever and pivot - the trike came with some reasonably nice forward controlls, but one thing I learnt riding my previous trike was that to drive quickly you needed to have your body weight inside the seat/bars centre line. Otherwise if the turn tightened you find yourself trying to pull the bars 'round whilst hanging on by whatever means. Anyway, to shift your weight you need your feet under you, hence changing back to original pegs - I will however, be keeping the forward sets as well, if I can.
     

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