The XT350 thread

Discussion in 'Thumpers' started by Burtonridr, Sep 26, 2007.

  1. Earthscape

    Earthscape Have ya got a helmut?

    Joined:
    Mar 9, 2006
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    Yeah, that's strange indeed. There is no battery in the system? I suppose the only reason for the small battery in the US XT350 is/was the various state law inspection requirements that say some of the equipment must operate with the engine off. Your horn must not work with the bike not running then, right? I looked back a bit in the thread because I thought you had described it earlier and I just don't remember - was this the way the bike was wired stock, or were you looking for that info a while back?
  2. Grreatdog

    Grreatdog Long timer

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    I believe the battery in a US XT350 is only there to supplement the stator output at low rpm. A US spec XT350 will run fine without a battery and all the equipment will work as long as the engine is at higher rpm. I ran mine no battery for a while and also with just a big capacitor wired in for the brake light when it didn't have signals.

    The stator doesn't put out enough juice for those to operate correctly at idle. Without a battery at idle you might get a bit of brake light but the turn signal flasher won't work. You can swap in a 12v camcorder battery and everything will work fine at idle. I finally ran a tiny little lawn mower battery to operate the brake and signal lights.

    The big Yuasa battery is extra tonnage they don't need.
  3. Lenz1

    Lenz1 Been here awhile

    Joined:
    Jul 11, 2010
    Oddometer:
    141
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    Queensland Australia
    The TT I'm rebuilding has an interesting mix of voltages.

    Power comes off the magneto in brown, yellow and white leads. The brown is completely unregulated AC that I've measured at over 60V AC ......one does not mess with a perfectly good ignition circuit - that's like jumping out of a perfectly good aircraft.

    The yellow becomes yellow /red.(Y/R) It runs into the handlebar light switch and is linked to the voltage regulator when the lights are ON. Yellow / red and white are not joined however when the regulator is linked to Y/R, voltages in both Y/R and W are reduced typically to 12V AC in the Y/R and 20V AC in the White

    This wiring strategy with the elevated voltage in the White allows the production of a crude form of Direct Current (DC), supposedly at 6V DC to power indicators, horn, brake lights, instrument lighting plus charge a small 6V lead-acid battery.

    The only gain that I can see to using 6V is a very small cost saving on an electronic component (bridging rectifier for both sides of the AC wave for 12V DC) and the reduced weight / size of a 6V battery.

    I'm gonna see how the lights etc behave on 12V+ AC around town / in traffic before going to Plan H - creating a 12V DC circuit with battery off the White circuit.
  4. Lenz1

    Lenz1 Been here awhile

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    The light switch now runs hi and lo beams in the hi position, bridge rectifier on the white circuit will provide 12V DC - 20VDC for tailight, brake light, indicators and horn. A capacitor will also reside in the DC circuit to smooth the wave and provide low rev power.
  5. hondaacclx84

    hondaacclx84 n00b

    Joined:
    Mar 24, 2012
    Oddometer:
    6
    Is someone here running a Vapor dash? I've been thinking about getting one and relocating a different key switch to the side of the headlight as some of the DRZ guys.
  6. xt4ever

    xt4ever Adventurer

    Joined:
    Jan 26, 2010
    Oddometer:
    80
    Location:
    Z, Spain
    Yes, I do. I have the Vapor just in front of the key switch. The key switch is in its original location
  7. Lenz1

    Lenz1 Been here awhile

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    Anyone tell me what's the rev limit on the XT350 / TT350 engines
  8. NordieBoy

    NordieBoy Armature speller

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    The Dyno says about 9,500rpm.
    Power has dropped from about 22hp to 16 by then.
  9. mustangwagz

    mustangwagz Been here awhile

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    Apr 8, 2012
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    Western PA
    so im lazy and i have turned up a few "repair" threads for intake boots. Im back in action with another non-road-legal xt350 (no title) boots are shot guys...whats best bet? Whos got em, and how much they gonna rake me for? lol Fill me in boys/gals! Cant wait to get the XT running beside my DR350! WOOOT!

    yah, n/m.. Took this in on trade for a junker...well i think i got a junker too. HAHA. something drastically wrong in teh engine..it tries to turn, then stops and WONT budge..so...ill be tearing the old girl apart.. Lots of other care needed for the old girl. It does have a Clarke tank on it though, so thats a plus. everything eles is there..but in rough shape. Oh well, only time will tell! OH, one last thing, it IS missing the skid plate..bummer!

    PS, its an 89.
  10. Lenz1

    Lenz1 Been here awhile

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    Thanks for that Nordie.

    There's a blanked off drive point on the engine that I guess is the take off for a tachometer but I'm thinking of a Tiny Tach tacho / hourmeter to keep track of maintenance and upper rev limits. It's high revs that crack / destroy pistons. The Tiny tach is reliable, transferrable and very versatile (I used one to match the right propellor for best engine revs on my little fishing tinny)

    I haven't had the opportunity to really wringe this thing's neck yet but short bursts of accel up the street ( just running it in officer) - have me VERY happy with how hard it drives in 3rd and 4th gear @ 14:50 gearing. At 14:52 like the 450 KTM's run standard, this thing would be seriously active in the dirt. Gearing is everything - so is a cylinder head with inlet ports that work well.

    I got a lovely surprise this afternoon when attempting to drain the front forks - no drain points in the fork leg. So it's "off with yer legs" , tip them upside down, drain out that soft 10W oil, reassemble and fill each leg with ~ 550cc of 15W fork oil. Just the little surprise needed when the bike is to be inspected / certified tomorrow at 09:00hrs prior to road legal registration - also tomorrow.

    I am looking forward to presenting the finished beast to the previous owner - my nephew - for a test ride (no 5th gear burnouts Andy please) and a comparision to the 2012 KTM 450 EXC "Six Day" he is using to currently stomp on his riding mates.
  11. JensEskildsen

    JensEskildsen Long timer

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    550cc is way too much, its even too much for the much larger (longer stroke and wider) tt350 forks. Xt350 manual calls for 319cc.

    Regarding revs, I usually dont rev mine out past 7000, and usually a lot lower, there seems to be more power in the next gear for me :)
  12. NordieBoy

    NordieBoy Armature speller

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    The fork mod from back in the day was 5w oil to get some suppleness.
    Even the White Power TT350 (1988 Dirt Rider mag) used 5w in the front.

    I think max torque is around 6,000. So no real need to go past 7,000 unless you're already in top.
  13. RunningBare

    RunningBare Been here awhile

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    Mar 30, 2006
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    miles from nowhere
    The handbook I have for a '85 TT350 says 533ml
  14. mustangwagz

    mustangwagz Been here awhile

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    Western PA
    Well its partly and mostly junk.. Tore top end off it today guys, My newly aquired xt350 needs help..or sold in pieces. lol One intake valve bent, One came comletely apart. Banged up piston a little bit, not much, and banged up head a little bet too. over all not really that bad..i could proabbly put it back together with parts and run it ill bet! lol Oh, would need a new timing chain too, this one seems to be stretched way out!!..but i got to many other projects going on, so ill prolly sell the usable parts and then scrap the rest. So if anyone needs something, let me know. It did come with an oversized clarke tank as well. Plastics are all there but rough. it doesnt have a skid plate though...bummer. My origianl XT did have one..i miss that old bike :cry

    anyhow, if anyone needs parts...hit me up. Thanks boys/gals.
  15. JensEskildsen

    JensEskildsen Long timer

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    I see now he has a mix of tt and xt, if not forks are tt, no problemo just a little over what my repair manual calls for.

    Id still use 10w at most, cant see the need to try and slow down the damping. But each to his own. :freaky
  16. Lenz1

    Lenz1 Been here awhile

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    The manual I've got says 533cc 10W oil in each fork leg. I loaded in approx 550cc of 15W oil because the springs are soft and the damping is just doughy.

    The end result is the forks now sit a little higher at rest and the damping is more to my taste. I made sure the forks were fully extended before the units were sealed so maybe it's a function of less air space in the fork legs that has produced the additional 10mm or so in the upright, no rider position. The bike seems fine on a paved road - we'll see when it hits the rougher tracks.

    The first inspection prior to road registration raised a few issues regarding the need for a lower rear guard and the use of the side stand cutout switch. Current Australian Design Rules (ADR) apparently specify a lower back end for the rear guard but I don't believe it's necessary given the original rear guard / tailight setup. The side stand cutout switch is a problem given I have to kickstart the beast with the side stand down and me standing on the left footpeg. One problem right knee compliments of crashing speedway bikes and a 6ft 2" body on "average" length legs has me unable to start the beast any other way.
  17. NordieBoy

    NordieBoy Armature speller

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    I used a bit of mud flap to extend the rear guard as it let's crap get thrown over the plate, tail light, bag, etc.
  18. RunningBare

    RunningBare Been here awhile

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    Yea, I have to start mine the same way due to really short legs. While doing this the side stand broke off I fell against the corner of a steel bench top, result, 6 broken ribs, punctured lung, pneumonia, cracked vertabrai, be very careful.
  19. Lenz1

    Lenz1 Been here awhile

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    That's one very savage "rip" to the ribs man - it sounds like a serious effort required to heal that sort of damage.

    The bike generally starts within 2 kicks but the focus of the problem is the erratic performance of the decompression assembly. Sometimes it will just roll over and start with almost no kickstart effort and others I have to really squeeze it up towards TDC and then kick.

    I've done all the manual adjustments (TDC then 2mm - 3mm cable freeplay) so there's no problem at the engine end of the cable, I wonder about the decompression cable engagement with the kick start lever - shit how much of this bike do I have to rebuild.

    Today I rebuilt the instrument light panel. The standard instrument light panel has 4 bulb positions, top left indicator, top right high beam, bottom left blank, bottom right neutral. These positions are marked on the clear acrylic panel cover. Well I am still defeated on how to get the indicators - left and right to run a single panel light so now the display has been "upgraded".

    I deleted the marked panel screen and replaced it with a clear faceted piece of reversing light cover to get rid of the orig printed marking. The display is now top row left indicator / right indicator (both green 5W), bottom row left blank, right is high beam 3W blue. No neutral light.

    I'm kinda old school when it comes to neutral lights and side stand safety switches - if you're dumb enough to try to kickstart it in gear / can't find neutral without a light or ride off with the side stand down then maybe a little pain will reinforce the correct procedure

    We'll see how the next inspection works out tomorrow - Oh the joy
  20. gearheadE30

    gearheadE30 Long timer

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    Small update, I just tried to install a TT600 remote-reservoir shock on my XT (with the early-style rear linkage that has less travel than the later, I think '89+, models) and it does not fit. At all. The upper mount of the TT shock is a larger diameter than the XT part, and the line for the reservior hits the mount. That could easily be fixed with some cutting, but the shock itself is also something like 2 inches too long. I kinda knew that going in, but was hoping I could make it work. Back to the drawing board.