Tav40 not working

BMPoland1993

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one more question. Something has been causing my chain to loosen enough for it to start 'skipping' or engaging on the sprocket in a way that causes a sudden bang from the back of the kart. My opinion is that the engine and torque converter began tilting slightly downwards, which in turn loosens the chain. Is there any way you could support everything so that it doesn't bend?

Thanks!
 

jamyers

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1. Good to hear you got the torque converter sorted!
2. I'm with Karl, if you have a welder it's fairly easy to make an air cleaner adapter - or do like I did, get a soup- or coffee-can, drill holes in the bottom to match up with the carb opening and bolt holes, bolt the can to the carb, and fill the can with bits of foam cut slightly larger than the can so they stay in there and filter all the incoming air. (picture below)
3. Looks like the left side of your converter is mounted VERY solidly with that chunk of aluminum, if the other (engine) side isn't, looks like it'd be easy to add a strut or two from the kart frame up to the mounting plate to support that side. First though, make sure the chain is tensioned to have just a hair of slack, no more.
 

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BMPoland1993

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OK I fixed the issue with the torque converter and engine leaning over causing the chain to loosen.

However, and slowly this whole thing is driving me nuts, my drive unit is sticking like heck! it worked fine in the beginning, and now its not disengaging properly and engaging erratically. I have a video on YT showing the problem, you can check it out. Excuse my Polish!
 

jamyers

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I have a video on YT showing the problem, you can check it out. Excuse my Polish!
Glad you got the chain sorted out, and don't worry about your Polish/English, it's all good.

But if you could post a link to your video, that'd be great - i searched on your username but couldn't find anything.
 

OPmini

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I've had that issue with the clutch happen to me too! what I did to fix the issue was degrease and re-lubricate the whole thing along with install a 2,600 rpm stall kit (from gopowersports) and weld the roller channels. these videos should help:
Cheap e-bay 40 series torque converter “VS“ original Comet PLUS // MORE MODS - YouTube
How to Make Your Go Kart Launch Harder ~ 40 Series CVT/ Torque Converter Upgrade - YouTube

NOTE: if you have a genuine comet you don't have to cut the welds. If you cant get the nut off you can cut the nut in half with a dremel and buy a new one.
 

BMPoland1993

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Turns out idle was too high. Messed around with the throttle mechanism a bit and now it's okay.

Although the reason why I'm writing is because i'm intending to buy a new carb for my 420 engine and need you guys to tell me what kind?

Thanks!
 

OPmini

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BMPoland1993

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What's a slide carb?

Stage 1 tuning never says anything about rods and flywheels. I do have 50pound springs?
 

OPmini

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A slide carb is a carburetor that controls throttle via slide, said slide it usually a cylinder or a D shape and moves up and down controlling the size of opening going to the engine (therefore it controls how much fuel mixture is added) most performance carburetors for motorcycles, dirtbikes, and minibikes are slide carburetors. When putting these on a stock engine an issue arises: if you look at how the throttle and governer work on the stock carburetor vs how a slide carb works you will notice that there is simply no way for the governer to do its thing. So if you put a slide carb on your engine and revved it up it would rev up and keep revving (because the governer cant work) and because the stock valve springs arent any good you will get valve float and kill your engine. However if you get better springs your con rod is just cheap cast aluminum so that will fail pretty soon and stock flywheels are only rated up to 6k rpm so go above that and that flywheel is gonna explode. So if you are interested in not destroying your engine I suggest you get these upgrades when putting a bigger carb on it.
 

BMPoland1993

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And air filter adapter and jetted carb + exhaust only? Will that setup be ok with just 50lb springs?
 

BMPoland1993

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ok thank you! could you please also outline the benefits and or/disadvantages of exchanging stock rollers/springs on a tav series 40 torque converter with medium rollers and red springs?

From what I know the engagement RPM of the converter will be higher, but more than that I have no idea.
 

OPmini

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ok thank you! could you please also outline the benefits and or/disadvantages of exchanging stock rollers/springs on a tav series 40 torque converter with medium rollers and red springs?

From what I know the engagement RPM of the converter will be higher, but more than that I have no idea.

Yeah really the only advantage is having a higher engagement rpm, This is desirable for engines with bigger carbs or running methanol bc their stall speed (aka idle speed) will be higher than an un-modded engine. After all, you don't want your clutch engaging at idle and stalling your engine!
 

BMPoland1993

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Just installed a new air filter w/ the filter adapter. Looks sick, will see tomorrow how it will ride. Just wandering if taking off the governor would ruin my engine?
 

BMPoland1993

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where can i get the parts for a Lifan 420? Not mentioning the fact that I live in Poland and getting these parts would be that more difficult.
 
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