Load testing a starter

Discussion in 'The Garage' started by DirtyOldMan, Oct 13, 2012.

  1. DirtyOldMan

    DirtyOldMan Long timer

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    I'm working on a 06 Husqvarna TE 510.
    It will start fine when cold but as soon as it's warmed up, the next press on the starter button blows the 15 amp fuse. I've been through all the wiring and connections carefully, replaced a worn ground cable, taken the starter apart and replaced the brush carrier. One brush (on the -side) was worn down about halfway.
    The starter has always (owned the bike 4 yrs,) sounded like it was doing all it could to turn the motor over and would even sometimes not turn over at all. All I had to usually do was push the bike slightly in gear to get everything in a different position and then the starter would turn it over just fine. It kickstarts easy as well.
    When it blows the fuse, it does it immediately upon pressing the button. In other words it does not labor to start and then blow.
    Not many moving parts inside the starter, the windings did not look burned, the armature did have a grey mark on it from the brushes but it was not worn.
    Starter spins freely when on a bench connected to 12v. I'm curious about how to measure what it's drawing when it's under load.
    I have a basic multimeter
    The bike has a new battery,
    The starter has been probably used more than the better rider would use one. It's not uncommon for me to stall/restart frequently.

    Any insight would be appreciated.
    A source for the Mitsuba starters would be valued as well.

    Thank You
    #1
  2. H96669

    H96669 A proud pragmatist.

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    Does it have a solenoid/starter relay? It should but may not be attached to the starter. That's what is usually fused, not the starter motor per se. So I'd look at that and the switch. Putting a screwdriver across the two big posts on most solenoids will bypass the switch function and should engage the starter, again all depends on what you have there, much harder to do with a relay setup. Watch out with the screwdriver....sparks may fly.

    But having to move the bike to rotate the starter and then get contact, that's usually a bad commutator. The part where the brushes touch, should be divided in rectangles, one of them may have failed and when the brush sits there....no contact, starter won't turn. You can check for that with the multimeter, one lead on the commutator body then hit all the contacts in turn, all should have continuity.
    #2
  3. speedracertdi

    speedracertdi Been here awhile

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    Does your bike have an automatic compression release? That could fail and overwork the starter.

    Other thing I would look at would be the starter solenoid it it's not part of the starter. Could have bad or dirty contacts.
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  4. DirtyOldMan

    DirtyOldMan Long timer

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    The solenoid is at the back of the battery and I can jump across the contacts and energize the starter even with the fuse blown or out.
    I'm starting to think the problem is the solenoid rather than the starter itself.

    But, a question, now I understand that it is the solenoid that is fused not the starter, could a bad starter cause this fuse to blow.


    I cleaned/tightened the external connections but was unclear how to get it open to have a look at the actual contacts. I'll explore that in the AM.

    I looked into the auto compression release, don't think it has one. The manual compression release cable is the only one present.

    Thanks for your help, m/c electrics confuse me.
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  5. H96669

    H96669 A proud pragmatist.

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    Universal type solenoids....they are pretty cheap if you want to save money over MC specific parts. I have a couple here that came out of garden tractors, I am sure I could fit that on a bike. I think the one on the garden tractor is out of an outboard engine....or was it an old Chrysler.

    Just to say that for post sizes, they are pretty well all the same, there is like 28 pages of them on Fleabay.:eek1

    I think your starter is OK. Now that I remember, the fuse was also blowing out of my old Honda way back then, kept kickstarting for a couple years til I replaced that solenoid.
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  6. ragtoplvr

    ragtoplvr Long timer

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    to answer one specific question. Solenoids that are mounted away from the starter, a bad starter can not make the solenoid blow the fuse.

    In the case where the solenoid is mounted on the starter, and has the function of engaging the drive, like used on HARLEYS, BMW, GUZZY, and probably some others, then it can. These solenoids have 2 windings, one is low current, and holds in the solenoid while cranking. The other winding is much higher current , and it used to engage things. once correctly engaged, this winding is disconnected. If the starter does not engage correctly, the high current can blow fuses.

    In your case, I think you need a new solenoid.
    Rod
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  7. GreaseMonkey

    GreaseMonkey Preshrunk & Cottony

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    It sounds like you have a bad armature winding that is shorted to ground.

    If you need to physically move the starter when it is on a dead spot before it will crank, that rules out the solenoid.

    To verify you need to disassemble the starter and check for continuity between the commutators, and also between the commutators and armature ground, but I suspect that if it is to the point where it is blowing fuses like this you will probably see which commutator is discolored and also has darkened paint on the windings.
    #7
  8. _cy_

    _cy_ Long timer

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    starters are never fused because of huge current draws up to 200amps.

    what are fused is starter relays. normally your starter button can only handle small current loads, usually less than what starter solenoid requires to function.

    if your fuse is blowing .. I'd be looking at what is blowing fuses by tracking down your starter relay. provided your husky has one... sorry not familiar with Husky. but all starters work this way. unless starter button can handle a large current. then no relay is needed.

    to test your starter ... after fuse blows... touch a wire from positive side of battery to solenoid wire that energizes starter. main cable from battery to top post of solenoid will always be hot.

    when solenoid is energized, top wire will make a connect with bottom spinning starter armature. solenoid will also engage starter tooth to flywheel ring gear.

    if you have an DC amp meter ... initial draw will be about 125-150amps, then reduce down to about 75amps or so. depending on how cold.

    your battery when fully charged should read about 12.8v resting. when engine is running depending on battery charge level... voltage should be from 13.8-14.2 aprox.
    #8
  9. Anorak

    Anorak Woolf Barnato

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    The Husqvarna uses a starter motor that is always engaged and an over running type clutch when the engine is running. What people are calling the solenoid is just a big relay.

    It appears he read your mind and took your advice before you posted it.
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  10. _cy_

    _cy_ Long timer

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    that's a new one on me... but that doesn't sound right... I'd believe the starter drive gears are engaged all the time. but not the start motor.

    in which case starter relay would work identical as described above. only instead of solenoid pulling starter tooth into ring gear ... solenoid would engage drive clutch and armature.

    here's the factory service manuals for download ... can't make hide nor tail out of it... beside chinese manuals, worst written manuals I've ever seen http://husqvarnaoutlet.com/repair_manuals
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  11. Anorak

    Anorak Woolf Barnato

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    Okay, the starter disengages when the engine starts and the gear over runs the shaft. Here's what it looks like on a flying brick. It's similar for just about every bike that doesn't use a bendix. I'm using BMW because I know the parts catalog and Real OEM has good graphics. Here's another example, a G450X which is also used in a Husqvarna.

    DirtyOldMan, test the continuity between every segment of the armature and the shaft. There should be no continuity. Use the ohms setting on the multimeter.
    #11
  12. anotherguy

    anotherguy Long timer

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    Anyone remember one of these?

    [​IMG]
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  13. disston

    disston ShadeTreeExpert

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    I have one of those but mine is really old. No meter instead it has a light bulb. I know it's used to test starter windings. I think it's used to test the rotor mainly, maybe the rotor only. But I don't know how to use it. I tried to figure this out on the internet but didn't get very far. Since then I've not really needed to test any rotors. It just sits on a bench in my room. One of the old things I can't bring myself to throw away. It has history.
    #13
  14. H96669

    H96669 A proud pragmatist.

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    You bet when I was young...an even older one with a bulb instead of a meter.Most of our old equipment was from the 30's when grandpa set up shop. Bulb lights when testing for continuity instead of the needle going up.

    Install armature on top of the "magnets", turn it on then using an old (or new:wink:) hacksaw blade laid along the windings, rotate the armature. If the hacksaw blade "magnetizes" anywhere on the outer part of the armature, it is bad.

    After that....black wire on the armature and touch each commutator in turn with the red, bulb will light if so equipped or meter will show continuity at each one . If one doesn't, that's bad. But you can easily do the last with a regular Ohmeter.

    Always had a kick with that growler....there buddy hold this just above there when I turn it on.:lol3
    #14
  15. _cy_

    _cy_ Long timer

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    does your growler look like this?
    from ebay for $39 ... have always wanted one after watching someone rebuild starter from a Triumph Spitfire when I was a kid.

    pretty coool process .. silver soldering new brushes, testing armature on growler, turning down armature copper pickup on a lathe, pressing new bushing, etc.

    [​IMG]
    #15
  16. anotherguy

    anotherguy Long timer

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    I knew that would bring the geeezers out. :D
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  17. _cy_

    _cy_ Long timer

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    ya I was talking to a custom rewind shop a few days ago about getting an airhead rotor custom rewound to higher spec's.

    charge was $85 to wind as much copper as rotor would take. conversation went to how shops like his was a thing of the past. when brand new armatures are available for airheads for less than he could wind it for. all with no cores.

    when brand new Chinese airhead starters are available by the crate for $25 each with no core. how can an American company compete? on top of that those starters are high quality.

    not a bad model...Airhead starters... buy for $25 each, then resell for $125-$150 each. No way he can compete ... he told me he used to rewind 100-200 airhead armatures per year... last year almost none.
    #17
  18. H96669

    H96669 A proud pragmatist.

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    Now I really feel old.:crySoldering brushes....turning armatures, did all that. I'll go click the switch a couple times on the old jointer....same switch.:lol3

    Old lessons however.....I don't let my starters go old and wear parts, I just inspect and if necessary rebuild them before they wear out. Old(er), poor...and BMW CHEAP!:lol3

    You better hurry and buy that growler before I start feeling like I should.:lol3
    #18
  19. _cy_

    _cy_ Long timer

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    by all means ... jump on it! like I really need a growler...

    already got more tools than anyone I know :eek1

    like that's stopped me before. truth is if I ran across a deal on a growler local. I'd probably take it home.
    #19
  20. H96669

    H96669 A proud pragmatist.

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    Shipping costs to Canada:cry....not tempted anymore.:huh
    #20