Home Forums General Karting Discussion Motor won't start, need help…

This topic contains 45 replies, has 5 voices, and was last updated by  David hofflinger 2 years, 5 months ago.

Viewing 21 posts - 26 through 46 (of 46 total)
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  • #48446

    David hofflinger
    Participant

    What is the crank trigger magnet? I got a magnet that goes in between the stater, but it doesn’t fit properly on my crank shaft, the original magnet fit but the new one the kit came with is bored way too big

    #48478

    Jim Derrig
    Participant

    The trigger/magnet fits over the crank, on the  side of the motor nearest the seat, and sits inside the “donut” of the stator. The magnet position is fixed by a key in the keyway on the crank output shaft.

    If the “original magnet” you speak of was off a push-button start ignition system, it won’t work correctly with the key start system and this explains your weak spark.  Though, to be honest the motor will run with the wrong magnet (I’ve done it–blush) so this does not totally explain the non-start.  My guess is the the weak spark combined with no choke may be the reason.

    Seriously, get some starter fluid for the first start.  Not ideal, but at least it’ll catch, you’ll get the break in started, and the next start should be easier.

    I have no explanation for why the new magnet would be “bored way too big,” as the magnet bores are identical for both (the crankshaft diameter for all Leopards is the same).  Wait, maybe it’s the trigger for the X-30 engine and they sent (or you unknowingly ordered) the wrong ignition kit?

     

    #48504

    David hofflinger
    Participant

    <span style=”color: #000000; font-family: UICTFontTextStyleBody; font-size: 17px; line-height: normal;”>When I tried starting it before I used starting fluid but nothing happened. I did not choke it though, the only thing is when I bought the motors used before I rebuilt it, all I had to do was spray the starting fluid in the carb and it started right up. I’ll try to choke it like you said. I’m hoping that’s the issue. </span>

    #48514

    David hofflinger
    Participant

    Like, even when the motor turns overs the gas doesn’t get sucked into the motor, just sold out the carb. And it won’t even attempt to combust, it just turns over. Can choking it be the cure? Also before I rebuilt the motor starting fluid started it right up, I tried spraying starting fuild into the carb recently after I rebuilt it and I got nothing. But tomorrow I’ll attempt to choke it like you said and hopefully that’s the problem.

    #48543

    Jim Derrig
    Participant

    If fuel is going through the carb into the plenum, then there has to be some compression pumping the fuel.  The only way I can imagine that NO fuel would  go from the plenum into the crankcase is if the reeds were completely shut somehow.  As I said earlier, the volume of fuel going through the carb is so great at low rpm that you’ll get quit a bit of it dripping out the front of the carb.  Seriously, on my X125t I get fuel dripping out the front even at 4000 rpm.

    If you use starter fluid it should fire without choking.

    I’m pretty much at a loss and suspect there is something misassembled on the motor, or your ignition system is for an X30 and the timing is so far off the motor won’t start.  You might have to bite the bullet and take it to a kart shop where somebody can give it a hands-on look, as remote internet diagnosis isn’t working.

     

    #48546

    David hofflinger
    Participant

    If only there was a kart mechanic around Vineland New Jersey lol

    #48547

    David hofflinger
    Participant

    Now I put the motor and everything back together again, new issue, the kart won’t turn over now. At all. It looks stuck

    #48559

    Jim Derrig
    Participant

    Well, this pretty much confirms my guess that something was misassembled the first time.

    You’ll have to put the motor in a box and send it to a builder.  I know–$$–but at this point you don’t have much choice.  I’m way over on the left coast, so I can’t recommend anyone over there.  Italian Motors was the IAME importer for decades and knows more about the Leopard than anyone else.

    http://www.italianmotorsusa.com/pages/im-engine-building-department

    Or you could just trade it in for an X125t–be the first on your block to own one 🙂  Might be cheaper in the long run.

    http://www.italianmotorsusa.com/products/x125t-mx-engine

    #48589

    David hofflinger
    Participant

    I found out it’s the new cylinder. It’s a hair to short for some reason and making the piston hit the head. I’ll need s thicker gasket and then it should run. S

    #48597

    Walt Gifford
    Participant

    Dave, you know I’m in Bridgeton.

    Gif

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

    #48625

    Jim Derrig
    Participant

    I’m not a pro engine builder but I’ve rebuilt and successfully raced about 6 Leopards and I don’t think the sort of interference you’re talking about is possible with correct parts and assembly.  I’ve never measured it, but there is ample clearance from the top of the piston to the top of the cylinder, and the concave shape of the head should make contact impossible.  Something is seriously out of spec and I’d be concerned about interference popping up again after the parts heat up and expand, as the available gaskets are not that different in thickness.  You should never have to fashion your own gasket to create clearance on this motor.

    I know you want to save $ but seizing the motor at 15,000 rpm will not be the way to do it.  I’m a DIY guy all the way, but as Dirty Hairy said “A man’s got to know his limitations.”  Sometimes you just gotta bite the bullet and pay the man.  Heck, for all you know you’ll get it so the thing will rotate again and you’ll only be back to it not starting.

    #48640

    David hofflinger
    Participant

    <p>I just send back the cylinder I got on eBay, the one that was too short, the guy actually shimmed the top of it off and didn’t tell me. So I dropped the old one back on just to see and it turns over fine now. Weird. And Walt, you’re in Bridgeton? If I need help I’ll contact you somehow</p>

    #48687

    David hofflinger
    Participant

    So I’m getting spark and I tried choking the motor, I’m getting nothing still. I even tried starter fluid right in the cylinder and nothing. I’m at a loss for words. Carb seems to be sucking in gas. Everything is lined up.

    #48693

    Walt Gifford
    Participant

    Compression, fuel or spark has to one of those 3. Are you flooding it?

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

    #48714

    David hofflinger
    Participant

    GOOD NEWS! I got it running. I still don’t know how but I tried the old spark plug and it started right up. For some reason the new plugs were not working and I know…it’s strange.

    #48734

    Jim Derrig
    Participant

    It’s possible your the lead wire off the coil is broken or beat up to the point it doesn’t work consistently any more.  Usually its then end with the spark plug boot.  Try twisting off the boot, cutting off an inch of wire or so and twisting the boot back on.

    The coils themselves are almost indestructible.

    #49479

    David hofflinger
    Participant

    Okay, so I had the kart running and stupid me forgot to put the small o rings on for the cylinder head bolts…Coolant leaked out while running and went into the cylinder and stopped the motor. Now I dried everything out and now the motor will only turn over…it won’t coma bust so I’m back to squar one. And today after I’d crank it the starter stopped engaging…I assumed it was a bad battery and bad starter so I got a new starter and battery…still doesn’t work. The motor turns over but the starter won’t engage to grabs the clutch. In all honesty I’ve never worked on anything so temperamental and confusing.

    #49740

    Walt Gifford
    Participant

    Maybe try fishing?

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

    #49785

    David hofflinger
    Participant

    Alright I fixed it, come to find out it was the starter and bad battery. The only question I have now is why it won’t keep running if I let off the gas, I have the idle screw set up but the motor dies as soon as I let off. It’s a 2 stroke and I know a lot of guys who race dirt bikes don’t want there bikes to idle at all.

    #49787

    Walt Gifford
    Participant

    If you want it to idle screw in the low needle until it idles but when you get on the track it will be lean under load. If you want to run it on the stand with the track setting you have to keep revving it but running on the stand will foul your plug so only run it for a few seconds to prime it for the grid.

    Gif

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

    #49792

    David hofflinger
    Participant

    Perfect, thank you everyone for the help. It means a lot. I can finally says it’s ready to race.

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