Yamaha Jog 50cc Stripped & Stretched

Discussion in 'Scooter Projects' started by BunnyMum, Apr 8, 2017.

  1. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    So I actually only got this because I needed a few parts for my Neos build and this had all the bits I needed and was cheaper to buy as a whole than getting the bits individually...but encouraged by finding out that it actually runs, and needing a guinea pig to do a stretch on, I guess it's getting built.

    It's got what looks like an iron cylinder so wondering if maybe it's got a 70cc kit on or something.

    Basically the "plan" is nothing fancy...super minimal, stripped down & stretched...aaaand that's about it. I have a bunch of panels but I don't know whether any of them really fit, and I'm not sure I care, but I guess we'll see.

    I was sorta planning to just use whatever I had left over from the Neos and throw something together, gear it low and maybe try using to learn to bike-drift but now I don't really know.

    Either way - today I was doing a dry run of making a stretch kit for the neos, since I figured there was a learning curve involved and this bike was already mostly in bits so was easier to work on than the neos...so now it's stretched :cool: (and I have to say I kinda love it!)

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    It's stretched about a 12" and although the carb will need a little bit of re-locating, apart from that it's actually looking pretty good. It's *so* low now. There's a few bits of metal which hang down from the frame which will go soon to give it a bit more ground clearance, but apart from those the ground clearance is surprisingly good.

    I can't really move it atm so no decent pics from the side but tomorrow I'll weld up some struts so that it can support its own weight and be moved. So far so good! Can't wait to see how the Neos will turn out - with the super wide back wheel it looks like it'll be pretty badass :D
     
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  2. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    w00t! it's done \o/

    Annoyingly I ran out of argon just as I got the TIG set up so ended up having to mig weld it..not as neat but still functional and a lot less fannying around.

    It's now back together, and supports its own weight, works really well in fact, no play or dodgyness whatsoever. The only slight issue I have is that the shock is more at an angle now and so it's a wee bit soft for my liking but I'm sure there's uprated springs to be had which will sort that out.

    The frame is securely locked in place by the original engine mounting bolt and one of the vertical struts mounts where the shock used to go, so it's going nowhere. I added a second vertical strut on the other side so it's even and for additional support and to prevent any twisting. That strut is just shaped to fit and rests on one of the cross-tubes

    Due to the stretch a few things don't reach now so will need re-locating - e.g. the coil/HT doesn't reach anymore, nor does the rear brake cable, and as mentioned before I'll need to build a little "inlet manifold" out of ali tube or something to locate the carb nicely..but otherwise it's pretty much good to go. I even had time to give it a lick of paint so it shouldn't rust.

    I think the stretch has freed up some space to tuck the battery out the way now, and/or I may relocate the oil tank to somewhere in the vacant space so I don't need the side panels anymore. I tried fitting some of the body panels but they don't fit terribly well and I seem to be missing a key one which wraps around the rear of the seat..so will probably stick with the "no panels" approach or possibly make new "minimal" panels out of thin (car body gauge) steel.

    all in all...well chuffed! can't wait to get her running and go for a ride :)

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    Last edited: Apr 9, 2017
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  3. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    relocating the carb seems to work - I made a nice little adapter out of ali pipe which meant the carb was relocated just down and left a bit so it sits next to the cylinder...that broke during fitting, so I started over and made another one out of steel pipe (25mm electrical conduit) - not as pretty but much stronger. I pulled the coil off and welded it back onto the frame in a more suitable location, extended a few hoses and she fired right up (using easy start) \o/.

    It still doesn't really run on its own yet but on easy-start it runs as well or even slightly better than before, so now i just need to sort out the carb since it still seems to be a fuelling issue...but it does actually run now, post-stretch, which was what the point I was trying to get to. There also seems to be a nice little space left over to tuck the battery in so will need to make a little bracket/box for that. For now though, that's enough and I'll take it - progress :)
     
  4. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    whilst pondering on the neos today and comparing notes with this one re the stretch frames, I realised I can potentially drop this bike another inch and at the same time resolve the slight "sag" issue it has. Hopefully just shortening the vertical supports slightly will also bring the rear wheel slightly closer and give the shock a little more preload.

    That's the theory anyway ;)
     
  5. Sam phantom

    Sam phantom Active Member

    Messages:
    874
    Looks really good mate can't wait to see it back up togeather with panals ect... you clearly have put a lot of effort in so far
     
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  6. Lil' Paddy

    Lil' Paddy New Member

    Messages:
    17
    Looks cool as man!
    I just got home from giving my mate a dig out stick a Honda lead 125 Motor into his little vision 50 we had to stretch that a little too but it turned out ace I'll throw up pics of the mount if you're interested in seeing it ;)
     
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  7. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    thanks :cool: and re pics awesome please do..that sounds like a fun swap! glad to see there's other ppl on here doing similar stuff :D
     
  8. Lil' Paddy

    Lil' Paddy New Member

    Messages:
    17
    Here's the Scoot and the mount!
     

    Attached Files:

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  9. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    So - got her running today, still need to reduce jet size a bit i think but definitely progress.

    Since the engine is working I figured I ought to probably add things like lights and brakes so it would have a hope of going through an MOT. Unfortunately I think the master cylinder (front brake handle) might be shot since it wasn't really doing much..but I'm sorta hoping it might magically fix itself. Will test again next time I get chance.

    I also figured I'd have a go at mounting some of the fairing and stuff back on - have had to improvise quite a bit due to the modifications but it's actually starting to look sorta like a complete bike (mostly).

    20170521_191618_www.jpg

    The fairing isn't really supposed to go with the bigger neos front end which i on it currently but till I get the right tyres on the right rims it is what it is and I made it fit. I actually quite like the slightly chunkier look of the neos front end but the 130 tyre needs swapping to the back (which currently only has a 120).

    There's only actually about 50% of the fairing present but that's ok - I'm still trying to keep it "minimal" whilst having a bit of protection from the elements.

    on the back I'm still missing the bit which wraps around the seat - i've yet to figure out what that even looks like but the rest of the jigsaw puzzle is sorta starting to take shape.

    Given I've cut bits of the frame away from the underside that might need something like plate ali cutting to tie it all together, and I'm thinking probably a crossbar to stiffen the frame somewhat, as well as allowing me to not have to get new longer throttle & rear brake cables. They currently both *just* reach but only if they're routed where a cross-bar would go..making a crossbar is easier and cheaper for me than getting new cables so that option wins :)

    20170521_191550_www.jpg
     
  10. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    7,321
    Love it, you should make a few of those brackets and sell them, would sell good I think
     
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  11. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    thanks, glad you like it, I'm pleased with how they're both progressing.

    umm I hadn't really considered that. I thought I was pretty much the only one into these stretched bikes :eek:)

    I suspect the issue might be not so much the stretch-frame itself which was pretty straightforward, but all the knock-ons..like having to relocate the carb (with custom manifold), extend or re-route the brake/throttle cables etc, relocate battery, coil, rear shock mount etc. I dunno if it would be possible to cover all that in a bolt-on kit...and anyone who can do the rest of it can probably also make the frame.

    Maybe it'll get easier once I've done a few of them...I'm learning stuff about the different approaches with each one.

    I guess it might be possible to offer 'conversions' though..I could be into that approach. It would solve all the knock-ons issues and im deffo into building whacky stuff ([cough] akira bike next [cough]) ;)
     
    Last edited: May 22, 2017
  12. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    after getting fed up with faffing about with the carb yesterday and apparently getting nowhere I took the carb to bits again and wanged it in the ultrasonic cleaner overnight. I'm sure I must have got some muck in there with the frequent jet changes.

    Either way though the only way the standard cables (throttle & rear brake) were going to fit by getting routed direct so it needed a crossbar to attach them to...so now it has one \o/

    I spotted some of the welds for the foot-peg assembly were a bit nonexistant too so sorted that and generally beefed up that whole area a bit while I was in there, then the whole lot got a nice thick coat of hammerite and we're good to go.

    I'm not fussed about making this bike perfect - I'm sorta testing two approaches...on the neos I'm doing everything "perfectly" and on this one I'm just getting it done with whatever is to hand. Besides I'm kinda digging the "rat" look atm so a ratty stretched scoot would be kinda fun, plus I don't have to worry about scuffing it :cool:

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    Last edited: May 28, 2017
  13. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    this bike still being a b**stid...I had it running ok-ish, but it idled like s**t and I was getting fuel washing back out of the carb when it stopped. I figured that was because the carb was "downhill" of the inlet manifold. Made a new shorter manifold and since then it doesn't run at all, even when I put it back on the "downhill" manifold. arrrrrg!

    Still runs fine on easy-start but dies as soon as that's gone. Sadly I don't really know enough about carbs to say what's up with it other than it seems to not be getting fuel. Am half keeping an eye out for a standard replacement carb from a working bike just in case it's that (PHVA 12mm if anyone has one for sale).

    In the mean time I'm trying to collect the few missing panels and bits and bobs so that I can have a shot of making it vaguely roadworthy once its running.
     
  14. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    Ok so I've been watching a lot of youtube vids to get more familiar with carbs, to properly understand what's going on with the lack of fuel on this carb..and as far as I can tell the fuel isn't getting into the bowl reliably. I don't quite know why that is but i think it's something I'll figure out eventually at leisure.

    In the mean time however, given that the bike runs fine on the other carb I've ordered a nice 17.5mm dellorto so hopefully it'll run on that, or the carb from the other bike...whatever. Either way my priority is to get the bike running, by whatever means necessary, and hopefully this will do it.

    We've also got a nice new front brake assembly from a neos en route so hopefully we'll have a working front brake, which will obviously be needed for the mot.

    Once it's running there's really only a few little niceties to figure out before it can get MOTd - like lights and indicators etc. The wires and components are there, they're just a bit of a mess atm so will need to sort that out. That should be no biggie though given I've rewired the neos already and they look almost identical.
     
  15. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    new stop and, more importantly, *go* \o/

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  16. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    It runs on the new carb \o/ and now also has a working front brake. winner :cool:

    Naturally it wasn't *quite* as straightforward as that but I got there. It doesn't run great - atm it'll either idle ok, or with a bit of coaxing it'll rev, but usually after a bit it cuts out. However it doesn't piss fuel out everywhere like it did on the other carb so that's already a big improvement.

    Tbh I'm not that bothered that it runs rough at this point. As long as it runs I can make sure the lights and stuff it'll need for the MOT are working and the place which will be MOTing it can figure out getting the carb to run nicely when they do the MOT. I'll defer to their years of experience there, esp as my thing is more the metalwork/building. Torturing myself for days on end trying to get a decent basic setup when I just wanna ride it now doesn't have that much appeal

    Have ordered a digital tacho for it to help with tuning and generally let me know what' shappening a bit more than by guesswork.

    all in all though - result :D
     
  17. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    while running it the other day I noticed the oil pump didn't seem to be doing much. I realise it's not supposed to pump loads and the pipe did fill up eventually but just in case there's a problem with it I've ordered a replacement from pedparts. It's their one where you can swap out the plate to give different mix ratios (prob won't need that) but it also has a metal drive gear, so should hopefully last longer than the plastic standard one.

    While doing that I'm going to see if i can change the oil seals...on the flywheel side anyway. It seemed to backfire from that area once or twice so I figure freshening things up in there wouldn't be a bad idea.
     
  18. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    progress!

    so I just changed out the oil pump for one of the "performance" ones where you can adjust the mix by putting different backplates on. I went with 40:1..I hope that's the right one.

    While i had that side in bits I changed out the crank seals since it sounds like dodgy seals there could mean trouble starting/running (which I've had). I also put new hoses on for the oil feed and the vacuum line to the petcock so that there was no scope for leakage - before I had a dodgy mishmash of random hoses which can't have been helping. That whole stator-area was pretty skanky so I cleaned it all up, re-greased everything too. Much nicer now.

    Once all back together it was a little reluctant to start but then actually ran a lot better than it did before...almost "stable". Re-starting it also seemed easier.

    We have a new "challenge" now though - now when it runs it's making quite a lot of blue smoke so I suspect the crank seals on the other side need replacing too..I guess it's sucking oil in from the gearbox now that there's an actual air seal on the other side. So that's the next project.

    At least I know it's getting oil to the engine haha ;)

    I think I'll need some special tools to do that side - not sure what they are but I guess this is where I get familiar with the gearbox side of things.
     
  19. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    7,321
    There is no oil for it to suck in
     
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  20. BunnyMum

    BunnyMum BunnyMum (aka Northcust)

    Messages:
    201
    Rides:
    YZF-R125 (180cc)
    yeah so I found out when I took the other side apart...doh :oops:

    I changed the seal on the other side anyway and now it doesn't run anymore (apart from on starter spray). This fking thing lol. Not sure what I broke but I musta broke something.
     

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