Home Forums General Karting Discussion Iame Leopard doesn't want to start, any ideas?

This topic contains 20 replies, has 6 voices, and was last updated by  tony zambos 7 months, 3 weeks ago.

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  • #23485

    Sebastian Sarmiento
    Participant

    Hey guys,

    I just bought this one. The guy who had it didn’t take much care of the kart, so I starting checking the whole kart and installed a new clutch and drum (He was running on metals),

    Install new O-rings for the water pump (didn’t have any), emptied the water and pour water wetter in it, new spark plug, new fuel lines and Rotax fuel filter, rebuilt caliper , new exhaust gasket and flex and bled brake lines and safety wired it, but didn’t touch the engine at all.

    I fired it up when I bought it and a couple of times after that as well, now it doesn’t want to start. There is spark, but the spark plug is dry, I noticed that the fuel barely runs thru the lines, fuel pump I’m guessing..?. Would one of those rebuild kit for the tillotson  HL344AB  help?. I don’t know much about this carbs and it would be easy just to buy one, but I’d like to get to know them and be able to perform a repair (if it doesn’t require some high mechanic skills)

    Thanks for your help!

    #23494

    Walt Gifford
    Participant

    Pour a little gas in the spark plug hole, if it fires and quits then it’s a fuel flow problem. Did you hook up the lines on the pump wrong? Did you wire tie all the connections? You could have dirt, did you clean the carb or at least check the screen under the fuel inlet?

    Gif

    #23497

    Matt Dixon
    Participant

    Pumper kit, buy more then 1

    #23502

    Sebastian Sarmiento
    Participant

    thanks for you inputs,

    to answer  Walt, this carbs have one inlet only, they are not like mikuni’s, there’s no way to hook them up wrong, I did zip tied all the joints and also this carbs have a kind of strainer that hold any residues that could come from the tank, in case are too small of a debris for the fuel filter.

    I did poured some mixed fuel in the cilynder and it did a couple of explosions like it wanted to start, I guess I’ll take out the carb, clean it and install a pumper kit like Matt said and see what happens.

    Hey Matt, all I can find are some Chinese kits, is there any site where I can get a better one or more original brand-like.

    Thanks again!

    #23503

    Brian Mead
    Participant

    Make sure the fuel filter arrow points to the motor.  May be on backwards.

    #23506

    Matt Dixon
    Participant

    http://www.shopswedetech.com/RK114HL_p/rk114hl.htm

     

    That’s a full kit, you can find just the diaphragms for $6 or so

    Always have an extra

    #23507

    Sebastian Sarmiento
    Participant

    Hi Brian,

    I double checked it as one of the first things , the filter is fine because the fuel went thru the filter and then it kind of stopped at the pump and it looked like it was moving back into the tank after that (not all the fuel in the line, but some). I was watching a vid of a guy showing something called pop-off pressure, after it pops-off the pump is supposed to hold certain psi (about 8) I’m starting to think the diaphragm is bad (a new pump rebuild kit should fix it.. I hope).

    Thanks for the tip

    #23508

    Sebastian Sarmiento
    Participant

    thanks Matt

    #23509

    tony zambos
    Participant

    If you don’t have fresh fuel in the tank, replace it.  Try to borrow a working carb.  Check the ground to the motor from the box and the ground that jumpers over the vibration mounts for the coil.  Open both needle valves for the carb roughly a turn & a quarter. Try starting the motor without the air filter and a hand over the carb inlet. Crank it briefly. Should have some fuel spill out of the carb.  If you’ve taken the carb off, did you pay attention to installing the gasket so it doesn’t block the pulse port in the block and the carb.  good luck.

    #23510

    Sebastian Sarmiento
    Participant

    Hi Tony I did exactly what you are telling me except borrowing a carb, I wish I could, I don’t know anybody around here that has karts and a leopard more specifically.

    Thanks to all of you for your responses!

    #23543

    tony zambos
    Participant

    Last idea except for calling Jim Russell Jr. Is the starter turning the motor fat enough?

    #23553

    Walt Gifford
    Participant

    The connection of the fuel line to a Tillotson carb is notorious for air leaks try wrapping it again with 2 separate wire wraps also check the plastic cap for cracks under the nipple. Sometimes when fuel sits in a tank it can form goop in the bottom that will clog almost anything. Same thing if old fuel was sitting in the carb for long.

    Another way out possibility, maybe a crank seal popped out or a reed is broke?

    Gif

    #23585

    Sebastian Sarmiento
    Participant

    The fuel is fresh, when I first got it I dumped the old fuel, cleaned the tank and poured fresh fuel in it. I also ran a straight fuel line from the tank and double zip tied everything, checked for cracks (no cracks) and still don’t suck any fuel into the pump/carb. I just took the whole thing apart this morning, carb cleaned everything and ordered a rebuild kit.

    I’ll keep you posted of the results once I install it.

    #23651

    Sebastian Sarmiento
    Participant

    Well, Today I installed a new rebuild kit (OEM) and still doesn’t suck any fuel at all.

    It really peace me off when I tried to make things better and all these problems come up. The previous owner didn’t give a crap , zero maintenance on it and it was working OK, well I’ll never understand that side of mechanics…. Anyway to the shop tomorrow and thank you all for your help and advices.

    #23656

    tony zambos
    Participant

    Check your PM’s

    #23669

    Sebastian Sarmiento
    Participant

    Hi Tony, thanks for the link. I actually watched that vid yesterday a few minutes before got your message, definitively very helpful. Also found this pics step by step in this other forum http://www.arboristsite.com/community/threads/tillotson-hl-carb-rebuild-w-pics.64450/ .

    Everything confirms that It has been assembled properly. Now I started thinking about the reed valve but there’s something I don’t get. the reed valve is a one way valve that sucks oxygen and fuel while the piston compresses and it creates negative pressure (vacuum effect), now what’s  the job of that little hole (pulse port??) in the left upper corner then?, is it supposed to BLOW AIR OR SUCK AIR?. I’m guessing it blows air, put pressure in the diaphragm from above and opens the needle? But at the same time, by looking at the passages of the carb it could blow air into the tank, which it would cause the fuel to move backwards or not to move at all.

    I’ve trying to find a diagram of the engine , like cut in half to see how it works.

    I watched lots of two strokes vids yesterday, but none of the other 2 strokes seem to have a port or hole like the iame.
    If someone can school me on this , I would really appreciate it.

    Thanks again.

    #23702

    tony zambos
    Participant

    Good to see that our doing a lot of homework. The most common 2-cycles, like the Yamaha KT-100 and the Rotax, have external pulse lines attached from the crankcase to the carb.  The Leopard has a passage through the reed cage, eliminating the problems of dried out or pinched line.

    Your theory on carb operation is a little off.  The pulse pressure only affects the pump side of the carb, raising and lowering the pump diaphragm.  This action pumps fuel into the carb chamber, similar the float bowl on a car.  None of the pulse is felt at the tank.  The amount of fuel in the chamber is regulated by the needle valve.  You saw in the video, that he tested the pop-off of the needle valve with a pressure gauge. The more tension on the spring, the more fuel in the chamber and vice verse.  also in the video, he set the pop-off to 10 psi, + or – 1, and that’s a good place to start.  IMO, compressing the spring will get the proper pop-off for now but will eventually go back to it original tension. If you have the patience, you can cut little pieces of the spring off to lower the proper pop-off.  I think the best way is to purchase a kit with several springs of different tension. If you don’t have a pop-off gauge, get one. Eventually you’ll need one.  But to get your engine to started start, just about any pop-off will do so long as it not too high or low.

    Also look at the gasket between the crankcase and the reed cage to make sure the pulse port hasn’t been blocked off.  And hate to asked this, but does the engine have compression?  It’s a 2-cycle engine. All you need is fuel and air plus spark at the right time and compression.

    Keep plugging away on this.

    #23705

    Walt Gifford
    Participant

    It’s not only the reed to carb gasket, that hole has to be clear up through all the gaskets and plates until it gets to the pump. If you put any one of those gaskets on backwards it will block the hole.

    Hold your hand over the carb intake and crank the motor if it doesn’t draw fuel there’s something wrong.

    Gif

    #23707

    Jim White
    Participant

    Like Walt said. If the pulse hole is not blocked by the gasket on either side of the reed block and the pumper side is of the carb is right it should pump fuel. If you had the carb gasket or reed cage out it’s pretty easy to put the gasket on and backwards and block the hole. Been there done that. The hole were talking about is a small 1/16″ or so hole. The gaskets have a matching hole and so does the base of the carb. Start there.

    To choke it take the air cleaner off. Cover the mouth of the carb with your palm. Have someone crank it over and watch the fuel lines. It may take a little bit to pump up. Your hand should get wet with fuel to the point of flooding the engine. If you get no fuel with it choked there are few options, blocked fuel pick up or line, air leak somewhere (but I’d think it’s still going to pump up something being choked), carb inlet needle is not opening or the diaphragms are installed wrong.

    While the carb is of you can easily pull the reed cage to inspect them too.

    All this is based on the fact that you have compression. No compression and you get little if any pulse to the carb fuel pump.

    #23713

    Sebastian Sarmiento
    Participant

    Hey guys,

    Reporting back with the latest news! LOL.. Yesterday I kept coming back to the garage until 11pm. I just couldn’t stop thinking about what was wrong. I did what Walt said, choke the carb 100% with my hand and it sucked the fuel lightning fast and dumped a chunk of fuel in my hand!. It did a couple of explosions  :) and I took my hand off and the fuel stop circulating again :( and the engine was dry again. Tried to start it several times and back to beginning , I could see a little bubble in the fuel line that wasn’t moving at all.

    This morning I took the kart to Cambrian Go Karts (local shop)Donald the owner said the compression seemed weak, but He wasn’t sure, in all this he checks the throttle cable and the carb was 1/8 open without touching the pedal. He said the engine would never start like that (I’m wonder how it started three times before), closed it up, fired it up and it started right up while I was scratching my head like the newbie I’m. (hey, at least I installed the carb kit right, lol)

    He also said that because the engine was left with fluids for a long time without being used probably the piston/ring are full of gunk and it creates friction inside the cylinder and that dragging could mislead to think the problem is poor compression, in that case a cleaning would do it.

    He’ll do a leak and compression test he said, after that, check the cylinder, ring, piston depending on results. Life is good fellows!. I smell a bill coming but at least tonight I’m not having nightmares with  carb kit!!.

    I really want to thank you all, you guys are awesome and your help and support means a lot.

    Thanks again!.

    #23728

    tony zambos
    Participant

    GREAT NEWS!  Enjoy your karting season.

     

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