Mezo`s 1988 XT600 Rebuild Thread (Project Ténéré)

Discussion in 'Thumpers' started by Mezo, Feb 3, 2010.

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  1. ActionManMelb

    ActionManMelb YAMAHOLIC

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    What you experienced was back EMF from the starter. If you run current through a coil of wire (inductor) and then suddenly remove the current source the collapsing electric field produces a much higher voltage the the original supply voltage. This is how the ignition coil works, but the efect is present in all circuits with an inductor.

    I am surprised Mezo, that you were not aware of that. Probably day dreaming in theory class all those years ago.:wink:

    You have a copy of the workshop manual. There is a section that details trouble shooting the starter circuit. Refer to that

    Regarding the single spark from the ignition coil. Many CDI ignitions systems will spark the coil once on ignition turn on and once on ignition turn off. This is normal and prove the coil and HT lead are working.

    If you are not getting sparks as you turn the engine then you need to trouble shoot the ignition pickup circuit and also the coil NEGATIVE.

    Remember that the coil negative is grounded by kill switch, ignition switch, side stand and clutch switches.

    Plenty of places to go wrong.

    Dont make me drive up there and set a new LDD record.:lol3
    LDD = Long distance driving.
  2. ActionManMelb

    ActionManMelb YAMAHOLIC

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    If any "SAFETY" switches have been removed then a loop is required to be inserted in their place.
  3. Mezo

    Mezo Banned

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    Sent from my iPhone using Tapatalk

    OK, that's what I thought for the clutch switch, it's a normally open circuit & by shorting it together that would bypass it thinking the clutch lever was pulled in.

    Again,,sigh.

    Give me 230/440v anyday. LoL.

    Mezo.
  4. Mezo

    Mezo Banned

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    Why does it do that eh? "Sent from my iphone using tapatalk" im back on the desktop now reading & just seen that on my previous posts.

    It doesn't say "Sent on my desktop using firefox" does it? what knob thought people would want to know that bit of useless information, what knob? a frigging nurd thought up that. :deal


    Anyhoo, yep ill try swapping the ignitor in the morning, there is a spare on the part bike i have & no we didn't try that today because we both thought it was the CDI doing its job (safety switch poorly bypassed).

    So Dave can you confirm on looking at your bikes there is supposed to be a sidestand switch & clutch switch? there are no switches on mine at all.

    Mezo.
  5. Adventurepig

    Adventurepig the bike, not me !

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    Hi Mezo

    !988 Tenere's sold in OZ had matching frame and engine numbers starting at 3DE-000-101 not 3AJ. the OZ 3DE model didnt have a side stand switch.

    may help,

    John
  6. luke111vh

    luke111vh Adventurer

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    my bike is a 3de as well and from memory it didnt have the sidestand switch or the clutch switch.

    i had lots of fun like you when i first got mine going as well, but i had to wire up a 550 engine to the tenere harness.
    i know that coloured wiring diagram for the 3aj is all nice and pretty, but its a real bitch to follow. give me a plain old black n white wiring diagram anyday.

    I know with my bike, if i hit the kill switch, pull the plug and & test for spark it gives 1 spark and thats it. i was puzzled for so long when i wired in the new basic kill switch and removed the right side switch block with all the electric start button etc. i would have spark with the kill switch off, then i would kill it, wind it over by hand and find it still had a spark. it took me a while to figure out it only gave 1 spark and thats it. dont ask me how or why, but thats what it does.

    go back to the cdi and check to see if the black/white wire has continuity to ground. it should be open to run. if its grounded, you'll need to work back thru the wiring harness unplugging things one at a time to see whats causing it.

    i wouldnt touch the cdi, coil, plug or plug cap or the ignitor, if its got a spark your half way there. if it had no spark i would look at those other things.
    to save time you could just unplug the black/white wire straight out of the cdi out of its connector, wind it over by hand see if you have multiple sparks.
    i did notice as well, the spark is very weak on these things turning them over by hand.
    its worth checking the resistance from inside the plug cap back to the coil as well. i found mine was very high resistance. i had to remove the plug cap, cut back the lead and refit. it made a big difference and got the resistance back into specs. ive come across this quite a few times on different bikes.
    if the resistance is still high check the cap by itself and then check the coil & lead - work out which one is at fault.

    i got a real good shock of my bike on friday when i was trying to figure out my battery charging problem. i had the earth lead disconnected and i measured the charging rate without the battery in the circuit just to see if the battery was dud and pulling the voltage down and i got a good kick with the engine running. frightened the shit out of me.
    i then found in the manual later or, do not disconnect the battery with the engine running you will receive a severe electric shock! it seems the excess voltage & current coming from the stator (I measured 40v AC at idle) is discharged to ground and if you touch it without a battery to absorb the load - you cop it.
    i wont do that again. it didnt quite feel 240v, it felt similar to grabbing a plug lead.
  7. metropolis2k

    metropolis2k Been here awhile

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    My 55W definitely doesn't have any safety switches like that. I ended up on my arse when kick starting it when I just got it (sidestand down, me standing up on the pegs) and it kicked itself into gear :lol3

    Just noticed on that lovely 55W you posted the tank graphics are wrong. The graphics on his helmet look great (I want one of those btw) but don't match with what he's got on the tank!

    Going to my parents' place for a few days over Christmas and I'm planning on getting the calliper installed, button everything else up and then trying to sort out an MOT :clap
  8. Mezo

    Mezo Banned

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    Thanks everyone for your input here, it is a 3DE (Aussie bike) so that means no side stand switch (less to worry about) but there is a a clutch switch for sure on Aussie models (mines not connected) Danny & i was shorting the cable out out to mimic pulling the clutch in as its an "open circuit" so id be able to just join them wires together & that takes care of that i think?

    Luke you said you was only getting one spark? do you mean if you take your plug out of your bike now & ground it to the engine & fire it up you still only see one spark? surely not?

    We was expecting to see a nice blue spark repeating itself, you know "tick tick tick tick" and we got this piss ant lame single spark. So you say pull the black/white wire out of the CDI & crank it by hand? why not just hit the starter button? you mean take the plug out of the side casing & turn the thing over with that nut on the magneto yeah? like i was doing in Perth.

    We did read through Danny`s manual & we did do a continuity check like it said, but we tried so many things yesterday both our brains were fried after three hours, we both needed to walk away & have a think.

    At least i know the starter on mine has a fault, it spins up no problem but its lacking grunt/torque and im wondering if Brian had this fault when he owned the bike? i seem to remember Graham saying they was bump starting it? Brian are you reading this? any input here would be appreciated. :D

    Mezo.
  9. Geoff D

    Geoff D Tenerista

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    Are you getting one spark when you turn on ign, or when you press the starter??
    Sounds suspiciously like the igniter to me Mezo but its hard to say when yer not there....
  10. Mezo

    Mezo Banned

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    Hi Jif :wave

    When we press the start button just one spark, never two, just one spark every time & its not a very powerful spark, well it doesn't look very bright.

    Mezo.
  11. Geoff D

    Geoff D Tenerista

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    I think Luke means he's turning it over with the kickstart, he doesn't have a button.....

    Mezo is it possible to completely bypass the ign switch, kill switch, etc by running a wire from the negative side of the coil to the cdi box? think thats what I'd be trying :deal
    I think you got something earthing out somewhere mate, or the igniter is f*cked.... wish I was there.... not to help, just to have a drink in the sun with Kylie while yer messing with yer bike :lol3

    You'll get her going today mate... :evil
  12. toysupra88

    toysupra88 n00b

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    Hey mezo,

    I was just having a problem with the battery. When it just went click, I had to take the seat off and wiggle the connection at the battery untill it would start. But you have replaced the battery...so that fault should have been taken care of.
    There was no side stand switch, but there was a clutch switch. I broke off the lever one day, and the replacement lever they gave me didn't have a spot for the switch.
    The kill switch is aftermarket....I don't know if you changed the wiring to it. I remember that being a bit of a pain to wire in. The only way I could get it to work is off is on, and on is off.
    The motor was burning so much oil I had to pull the spark plug out everyday to clean it. Other wise it wouldn't start.
    hope you figure it out!!
    Brian
  13. Mezo

    Mezo Banned

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    Hey Brian, i found the broken clutch lever in the bottom of the box & i was wondering how you was starting it? did you have it plugged in to the loom & did you press the button when you wanted to start the bike? id imagine if i just chopped off the socket & joined the wires it would work?

    And that helps with the start/run info, but im sure Danny & i tried it both ways? we was trying everything we could think of. :lol3

    And the starter Brian? you never had any problems with that obviousley then? so it must be something ive done wrong when i installed the new brush set. :scratch

    Thanks for the info mate it all helps. :evil

    Lots of things to try later, cant do nothing just now as Kylie was on a night shift last night & is sound asleep now (10am) and the bike is right under her bedroom, so ill go & fit the front brake line & put the fairing bracket back on now its welded & when she gets up later this arvo i can start turning the bike over again.

    Ive got a spare ignitor on that spares bike Geoff, ill whip that off & have a go, dunno if it works or not? cheers for the help mate.

    So when you coming down then Geoff. :evil

    Mezo.
  14. luke111vh

    luke111vh Adventurer

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    Mezo, you might need to go & re-read my post.
    It gives only 1 spark when the killswitch is on - or ignition is killed. eg - black/white wire is grounded

    When I said crank it by hand, i meant turn the kickstarter. I forgot yours is electric start. So you can press the button.

    What did the continuity test reveal at the black/white wire unplugged out of the CDI with one end of the multimeter going into the wiring harness end of that wire and the other meter lead to ground??

    Im pretty sure the clutch switch is only there so you can't start the bike while its in gear with the clutch out.
    So if your starter motor works now, i think you can rule out the clutch switch.

    Mine has only ever put out a pissweak orange spark. Remember these things are CDI and the faster the engine turns the better than spark gets.
  15. Mezo

    Mezo Banned

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    Thanks lads ive just figured what was wrong, I went & checked continuity between the rectifier & the chasis/negative & sod all, i thought huh? the rectifier is bolted to the battery holder & in turn is bolted to the frame.

    Turns out the powdercoat was so thick it was preventing the battery holder from getting a ground. :norton

    Haaa, so i scratched some paint off & hooked everything back up & bingo we have a multiple spark. :clap

    Gotta love the power of these forums eh. :evil

    [​IMG]

    OK on to my next problem. :D

    Now i did know about this problem yesterday but didn't want ask until id sorted the spark problem out (small steps) you guys know how it is eh.

    So the starter motor has been proven to be a duff repair on my behalf or its shagged? the spark was me not paying attention to basic stuff like grounding (common problem) and the next problem i have is oil. :evil

    We have filled the oil tank up before we found we had a spark issue, i had removed the top screw near the air filter as per Raul`s instructions on post 74 way back in February of this year.

    We have been turning over this engine big time trying to suss the spark issue out, as Danny was leaving last night id said to him "at least the dam things not pissing oil out of the engine" me thinking by now the oil would have been pumped around the engine, right? haaa, wrong again Mez old son.

    When Danny peeked inside the oil tank the level is the same as when we filled it in the morning, it has not dropped & in which case the engine is still empty then? how can that be if we have been turning it over & over & over again? surely it would have been pumped inside by now yeah?

    Luke? what am i doing wrong?

    Mezo.


  16. luke111vh

    luke111vh Adventurer

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    So it sounds like geoff was not right when he said it was the ignitor. it was just a bad earth engine to battery. i didnt say that the ignitor had to be grounded.
    I thought it was wiggywiggywildwildwest that said earlier just for a bad earth to the battery. but anyway, at least you got it sorted.

    That thing you are pointing to is the regulator/rectifier, not the ignitor. i thought u were talking about the ignitor coil inside the left stator cover.
    The reg/rec doesnt need to be grounded. it send the excess current thru the black wire coming out of it to the neg battery terminal. mine isnt grounded and it works ok. mine is screwed into the plastic rear mudguard and held on with a self-tapper!
    Just for shits n giggles, check the resistance between the neg battery terminal and the engine and then neg - terminal to the frame. you might still have some paint underneath causing high resistance. if its less than <0.5ohm it should be alright. (im sure you're already onto this anyway by the sounds of it)
    Even though my bike is not elec start anymore, i still used that big thick black earth lead that runs from the neg bat terminal down to the engine anyway.

    I remember when I first got the xt550 i kicked it and kicked it and kicked it and kicked it and still no oil came out of that little bolt. The engine needs to be running.
    maybe if you cranked it for 30mins or so you might get something coming out.

    Here's what I'd do with the oil problem.
    Pull that little bolt out of the top of the oil filter housing and run the engine until oil comes out of it while keeping an eye on the oil level in the tank.
    its a bad feeling knowing that engine is running without any oil getting to the top end for the first 30 seconds or so, but what else can you do?? as long as you put oil on everything while you assembled it, that should be enough to protect it until you get oil pressure.
    First time I did this it took probably 15-20 seconds to get oil coming out. keep the engine running and put that bolt back in. watch out because when it comes out, it will piss out of it. it will almost spray the fuel tank.
    keep the motor running and try and get 2.2litres into the oil tank.
    i've found even a quick spin around the block is still not enough to check the oil level properly. you need to put at least 2km on it.
    Come home, re-check the oil level ASAP. This is a pain in the arse, because I need to get the side cover off and the seat off so you can have a good look down in there.
    Top it up, go for another ride, go a bit further this time, come home and re-check.
    I've been over this so many times, ive had so many oil leaks on this bike, i think i've got them sorted now.

    someone said earlier the reason the oil pump doesnt do much sitting idling is because the oil pump is driven off the gearbox. im pretty sure this is incorrect. the oil pump is driven off the back of clutch so its running all the time.

    if you follow the oil flow it shows there are 2 oil pumps, one that feeds the motor and one that feeds the gearbox which also feeds some oil back to the oil tank via the oil cooler.
    My guess is because this oil return line is tee'd off from the gearbox supply, that the pressure is just not great enough at lower rpm to pump oil all the way back to the tank, and any pressure that is generated is just bled off back to the gearbox which would in-turn "wetsump" itself if left running at lowrpm for extended periods. (i think i just confused myself ):eek1

    [​IMG]

    It would have been nice if Yamaha had put in an oil pressure switch with a red light on the dash. there is no way of knowing that your bike is low on oil or if it has no oil pressure.
  17. Mezo

    Mezo Banned

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    I cant ride it yet Luke, not a that stage yet.

    What if i put it in gear with the chain off & then run it would that work?
    Im just having a feed & then ill go down & lob one of the 34L tanks on (only tank with gas in it) and see if it starts, gulp!!

    Im not bothered if it pisses oil out everywhere, im more concerned about running it without oil. :huh

    Ive cheated a bit & poured some in the side of the engine through the inspection hole, i thought it may help prime the pump easier? haaa your all going to say i shouldn't have done that eh. :D

    Oh well, he who dares Rodders.

    Mezo.
  18. ActionManMelb

    ActionManMelb YAMAHOLIC

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    Beat me to it, I was just about to tell you to put 1 litre in the LH flywheel inspection port.

    Good plan, worst that can happen that way is an overflow from the tank.

    The other way (no oil) could nip up the engine, wreck the crank and then I would really have to pull a finger out and finish the tute.:lol3

    Checked my 1VJ and 3AJ's and they all have a clutch switch and no side stand switch.
    My theory is that they probably have provision for one in the loom, but put a loop in or not for the various markets.
  19. Mezo

    Mezo Banned

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    Well it was a bit of a hash with the 34L tank to fuel the bike up, and the carb is leaking fuel out of the overflow, so i poured some water on to wash away the spillage, grabbed a fire extinguisher & thought bugger it lets see if it will start.

    <object height="385" width="480">


    <embed src="http://www.youtube.com/v/kE9Yc5E0W2M?fs=1&hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" height="385" width="480"></object>




    Yay !! :clap

    Not a puff of smoke or any knocks or rattles. :evil


    :freaky:1drink :photog :beer :kumbaya :drums :slurp
  20. ActionManMelb

    ActionManMelb YAMAHOLIC

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    Whew!!
    I think we all breathed a collective sigh of relief.:clap
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