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Bruce

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Posts posted by Bruce

    98 pw80

    in Dual Sport, Offroad Bikes

    Posted

    i have a 98 pw80 i bought about 3 weeks ago it was running like shit after i cleaned the carb jets an i juss bought a whole new carb an it fireds right up now the only thing is when i full throttle it in every gear it like bogging out so i have to let off the throttle to get it moving any one have any idea what i could do to get it running right please let me know thank you

    When you say bogging, do you mean that the motor will rev highly and then start to slow down and begin labouring? If so then your high end mixture is too lean. If the motor on full throttle transitions nicely from idle to mid range and then starts to labour without getting to max revs, making a cyclic laboured sound like a 4 stroke ("4-stroking") then you are what's called "burbling rich" on the high end. Before adjusting this, check the choke mechanism as more often than not, this latter is caused my the choke mechanism being stuck on.

    Also if it is this check the exhaust hasn't become coked up. A restrictive exhaust on these engines can unbalance mixture tuning / timing and make settings highly sensitive.

    MY BUDDIES

    in Yamaha Gallery

    Posted

    ha???what do u mean???

    I was teasing you that it's full of SOGs and other assorted lecherous dirty old men that will be slobbering like bulldogs before a feast. But you will, in honesty be treated like royalty, you just may not appreciate all your subjects though. Go have a look, it's a laugh.

    Xt sprockets

    in Dual Sport, Offroad Bikes

    Posted

    Thanks guys,hope I didn't start a domestic between you two..... :lol: my rear sprocket is a 47 and front is a 15,this is what the shop gave me as a chain and sprocket set :unsure:

    Aah, dont mind Mucho, I entertained myself for the last 3 odd years trying to wind him up. But it's like stirring pigshit...it just gets thicker. Sounds to me Andy, that you got a TT600 sprocket set. Nothing really wrong with that in as much as judging from the year of your bike it is a 3AJ model which is the same engine used in the TT's relaunched round abouts 2000-2.

    Xt sprockets

    in Dual Sport, Offroad Bikes

    Posted

    OMG what are you doing here? Bloody admin too! Ja, Anus, but you've been humping mine since 2004, what's new? :lol:

    Andy could use a 16 /42 or 14 /39 combo for the same results. More wear on the 14, less on a 16 combo's, however these changes may require a change from the 106 link 520 chain.

    Xt sprockets

    in Dual Sport, Offroad Bikes

    Posted

    Hi everybody,could anybody tell me how many teeth are on the front and back sprockets of an 1989 XT600 tenere?I just got a set and fitted them but the rear had an extra 9 teeth to the one that was on the bike originally,must admit the acceleration is a lot better,probably lose some at the top end but I don't really thrash it anyway,just a query,

    cheers Andy :D

    40 / 15 or any valid combo giving a reduction of 2.666

    XT600z gearbox

    in General

    Posted

    You might also want to check your clutch cable tension. Make sure the clutch is being fully disengaged. Good check is when the bike is cold (choke is on, revs a bit higher than norm etc). Does the bike snatch when engaging first?

    No spark

    in Dual Sport, Offroad Bikes

    Posted

    Oh, you dont want a wet plug. Dont use that as your yardstick. Rather look at the plug after running for a while to judge mixture. Remember these bikes run notoriously rich anyway.

    Are you using the correct amount of choke on cold starts?

    No spark

    in Dual Sport, Offroad Bikes

    Posted

    OK, thanks Bruce, tried your idea and lo and behold I got the beast started. Sure is hard to start tho. I can't count the number of kicks it took. Now it is still hard as heck to start cold. Have adjusted the valves and I know the valve timing is spot on. Have taken primary carb apart and adjusted float level and cleaned all jets and orifaces. Low speed needle is 1.5 turns out per manual and have tried another 1/2 turn out with no effect. Have pulled the plug and it is not wet at all after repeated kick tries. Any thoughts?

    Early kickstart TT's have a weak kick over spark. ... you generate the current for the spark on kick over not via battery.

    Make sure all lights etc are off.

    Have you got the kickstart technique right? A seemingly stupid question, but if you are new to these old 600 thumpers, they will start a dream if you kick them over right and be an absolute bitch if you get it wrong. ... feel for the near TDC compression by gently pushing down on the kickstart lever. When you reach it come back up on the kickstart and kick all the way through to the end of the stroke with firm pressure.

    Failing this have a look at the following to make sure you have a clean circuit:

    Side stand switch (if present of course)

    Kill switch

    Check all earthing points are clean and make good contact especially on any repainted surfaces

    Check the neutral cable (blue if memory serves) these go into the crankcase and can deteriorate and break under heat

    Recheck coil resistance

    remember a cold engine takes more electrical current to start than a hot one.

    If all these check out, then you need to make sure it is indeed an electrical problem. Remove the plug from the head so you have no compression when you kick her over, then remove the suppressor cap from the HT lead and make sure a bit of wire is poking out. Ask someone brave to hold the ht lead close to a exposed metal earthing point on the bike and kick her over with gusto. If the spark is orange = weak. Blue = OK. Now try it with the suppressor cap and plug in on the same grounded surface.

    No spark

    in Dual Sport, Offroad Bikes

    Posted

    I take it you have correctly connected the loom and checked resistances. I would agree the coincidence of a faulty CDI unit is unlikely. Last check I'd recommend you try is check the HT lead to sparkplug suppressor cap. Trim 2mm off HT lead, re-insert the cap and try again, as the HT Lead was known to be susceptable to corrosion in these models. Likelihood is pulling it off the plug was the last straw.

    xt 550

    in Dual Sport, Offroad Bikes

    Posted

    What happens at 4.5k rpm?

    Check your plug colour, it'll tell you a lot.

    Various checks you can do starting with easiest...

    1. Check the carb inlet mainifold rubbers are not leaking through cracks etc. Easiest way to do this is with the engine idling, spray easy start around the intakes. If you notice a rpm change, you have a leak.

    2. Check your filters are not dirty, and the guaze has not corroded restricting airflow.

    3. Check your idle mixture pilot screw is not set too rich / lean. Should be roughly 2.5 turns out. Note, this does not adjust fuel flow, but airflow so tightening the screw will richen the mixture. Check the vent in front hasn't corroded closed a bit.

    4. Use a clear plastic Tygon tube (battery overflow tube works well enough) attached to the float drain nipple and bend it back up against the float bowel. Open the drain screw and petrol tank cock. Measure the difference in fuel height from the bottom of the meniscus to the top of the float bowl. The fuel level should be within spec 5 - 8mm (check against manual for that figure tho)

    If you are still having problems, you'll need to strip the carb further.

    5. Check and clean all jets and atomisers. DONT forget the mini guaze filter that sits in front of the needle and seat either.

    6. Check against the manual that the primary cd slide closes to the correct point and is not compensating for the pilot jet ( idling issues)

    7. Check secondary carb is actuated at the correct point. Roughly once 8 - 10 mm of the cd slide has been raised in the primary carb.

    8. Check the fuel pipes between the carbs for integrity / leaks

    9. Check all diaphrams and the free and vacuum movement of the secondary carb

    10. Check the needles for wear and that they are correctly positioned with the retaining C-clip.

    Mechanical.

    Check that the valves are indeed within tolerance and that the decompression cable free play is not set too tight and then check that your cam chain tensioner has not reached it's furthest limmit introducing a mechanical timing error. If you get the chance to drop the motor check also the cam timing marks.

    Timing. Use a strobe and check against the manual that the timing is advancing corrrectly.

    After this you are pretty much into the electronic side. Check all cable connectors are making firm contact. Use contact cleaner and then use a multimeter to check against the manual the various resistance tolerances, but honestly, when you get to this point, it's often best to trial fit a part be it coil, stator etc from a donor bike to find the error.

    Goodluck.

    Edit

    Tufty wrote:

    You can't directly check your CDI without a known good one to check it against. It's a process of elimination, where if everything else fails, your CDI is probably shot.

    The 550 ignition system, being CDI and not TCI, is very simple. You don't need the reg/erct, battery, lighting circuit, etc. All you have is the generator, cdi, coil, plug, ignition switch and kill switch, the rest is entirely separate. Forget the battery circuit for the moment, it's utterly irrelevant.

    You'll need a multimeter, and an electrical schema wouldn't go too far amiss either - here's one in italian - http://digilander.libero.it/XT_550/I...co%20XT550.jpg

    First thing to do is to check the kill switch. All sorts of crap can get in there, they can block up and fail. It works by earthing the CDI, so the easiest way to test it is simply to disconnect it entirely. Check for continuity between the kill switch contact (where the black and white wire runs in) on the socket and the frame. continuity when in "off" position, none when in "run".

    Now the ignition switch (key). Check for continuity on the black and white wire running in and running to earth. Again, only continuity when it's off / lock / park

    Now check the wire feeding the kill switch / ignition switch from the CDI. There should be continuity between both ends (obviously), and *no* continuity from either end to earth. This is the black-and-white wire from the CDI.

    All good? Time to check the "hot" side of the coil. remove the sparkplug, and reattach it to the plug cap. check for continuity between the centre electrode and earth (should be) and the outer electrode and earth (shouldn't be, as long as the plug is away from the motor. Common failure here is HT lead disconnect from plug cap, shot contacts in the cap itself, shot cap, bad connect from coil to HT lead, bad connect between coil and earth.

    Test resistance of hot side of coil (resistance between orange lead into coil and plug electrode) against spec.

    Test resistance of cool side of coil (orange to black) against spec.

    all still good? Test continuity between orange from CDI to orange in to coil. should be good, with no continuity to earth.

    Now check the generator. continuity between red and brown from generator, and resistances good. No continuity between red or brown and earth.

    you can't really check the advance detector without a strobe, so plug and unplug repeatedly. contact cleaner if you have any. it's the 3-way connector from the generator with white/red, white/green and green wires.

    If that all still checks out, it could well be your CDI that's shot. double-check the earths (black wires) on the CDI to be sure, and all earth connections to the frame, but that's about all you can check.

    You can use a non-yam CDI to check, the easiest one to use is a C50/70/90 CDI (and has the benefit of being cheap as chips). This has no advance, so you connect to either the white/red or white/green pulser and the green, plus the red and brown. If you connect the wrong pulser your ignition will be too advanced, and it will throw you off when you kick it over. if you connect it to the right one, the bike should run, but you will only get about 3.5-4K RPM tops. This is all a last resort, though.

    FWIW, my money is on something being earthed that shouldn't, or a bad connection on your HT lead.

    Simon

    Carb on XT600Z '88 Tenere

    in Dual Sport, Offroad Bikes

    Posted

    On the carb (ignore the float bowl line and vacuum tube from afterburner to secondary carb and all other fuel links between the carbs) there are two outlet pipes at the rear of the carb (carb intake side).

    I suspect the one on the primary is an overflow, but haven't a clue as to the one on the secondary. Anyway, my inclination was to let them vent freely. Is this correct or do they have another purpose / connection?

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