Torque Converter staying engaged

[Noahcaleb]

I have got a 440cc Duromax engine on a Manco Go kart with a 40 series torque converter and I am having issues withe the torque converter staying engaged when idling, thus making it lurch forward on startup. I have adjusted the idle screw as far as it can go out, and the torque converter is very new. Any ideas how to fix?
Thanks

 

[Brianator]

Have you made sure the throttle on the carb itself is indeed closing all the way (by using your hand)?

Is there a air fuel mixture screw or is it a EPA carb with that sealed up? If it does have one you should be able to get the idle to drop a hair by unscrewing it just a little bit (it will enrich the mixture).

 

[Noahcaleb]

Yeah the throttle is closing all the way, and the mixture screw is sealed up as far as I can tell.

 

[Brianator]

Try running it with a some choke to see if it will idle it down, that will tell you if adjusting the mixture will help and if it's worth the hassle to get in to, there's usually a way even though it's sealed. Can you post a couple pics of the carb from different angles?

 

[Karttekk]

Maybe try disassembling it and cleaning it followed by a dry lube. It could be gummed up or sticking from lack of maintenance.

 

[Phil2]

I recently purchased a 40 series Torque converter from BMI karts as part of their granddaddy kit. The torque would stay engaged, i cleaned it same problem had rpm gauge so knew rpm was well below engagement rpm. contacted bmi they said i had a faulty torque converter and that i could grind down the "teeth" that were on the inboard sheave (this one mounts backward so the sheave that moves). after i did this the torque converter works great and disengages every time. I should have taken pictures...

It was driving me crazy, but now works great. might be worth a shot. it took an impact to disassemble driver clutch.

 

[repsejneslekkim]

I recently purchased a 40 series Torque converter from BMI karts as part of their granddaddy kit. The torque would stay engaged, i cleaned it same problem had rpm gauge so knew rpm was well below engagement rpm. contacted bmi they said i had a faulty torque converter and that i could grind down the "teeth" that were on the inboard sheave (this one mounts backward so the sheave that moves). after i did this the torque converter works great and disengages every time. I should have taken pictures...

It was driving me crazy, but now works great. might be worth a shot. it took an impact to disassemble driver clutch.

Hello

Please post some pictures. I have the same issue.

Jesper

 

[miniblazinbmx]

I recently purchased a 40 series Torque converter from BMI karts as part of their granddaddy kit. The torque would stay engaged, i cleaned it same problem had rpm gauge so knew rpm was well below engagement rpm. contacted bmi they said i had a faulty torque converter and that i could grind down the "teeth" that were on the inboard sheave (this one mounts backward so the sheave that moves). after i did this the torque converter works great and disengages every time. I should have taken pictures...

It was driving me crazy, but now works great. might be worth a shot. it took an impact to disassemble driver clutch.

I have this very same problem and have come across several with it with these knockoff comets, got any more info? I'll be cracking mine open this week before someone gets killed on this thing..

 

[madprofessor]

Nobody's making much sense the way it's being said................
(1): If a clutch wasn't disengaging, the engine would be forced to quit if the moving kart gets stopped, it would just choke down. Like my first wife trying to learn how to drive a stick shift.
(2): If you haven't turned down the idle enough to stop the engine from running, how do we know the problem's not the engine? If the throttle's being closed all the way, that means that unless it's bumping into the idle adjust screw the motor should shut down. How can a motor prevent you from starving it of air/fuel until it quits? Magic fuel and fresh air being mystically created inside the engine?
In essence..............if the kart's stopped with the motor running, the clutch did indeed disengage. If it tries creeping forward after that, you have to lower the idle speed somehow. If it's still trying to creep forward when the idle gets slow enough for the motor to quit, the problem's in the clutch. If the kart stops trying to creep forward before the idle slows down far enough for the motor to quit, then you fixed it.

 

[miniblazinbmx]

Nobody's making much sense the way it's being said................
(1): If a clutch wasn't disengaging, the engine would be forced to quit if the moving kart gets stopped, it would just choke down. Like my first wife trying to learn how to drive a stick shift.
(2): If you haven't turned down the idle enough to stop the engine from running, how do we know the problem's not the engine? If the throttle's being closed all the way, that means that unless it's bumping into the idle adjust screw the motor should shut down. How can a motor prevent you from starving it of air/fuel until it quits? Magic fuel and fresh air being mystically created inside the engine?
In essence..............if the kart's stopped with the motor running, the clutch did indeed disengage. If it tries creeping forward after that, you have to lower the idle speed somehow. If it's still trying to creep forward when the idle gets slow enough for the motor to quit, the problem's in the clutch. If the kart stops trying to creep forward before the idle slows down far enough for the motor to quit, then you fixed it.

I have a knockoff Comet 40 series and I can watch it not disengage when you let off throttle. And yes mashing the brakes might kill it if I could actually stop. Ive personally used the kill switch more than once. There are several videos of these sticking due to poor internal machining and slipping weights.
turning the choke back on drops the rpms and I can see the sheave disengage. The way I figure there is modifying the clutch driver to work correctly, or replacing it.

I also have a tuning issue after adding stage 1 filter and exhaust and it seemingly running lean or rich.. neither if which the idle has been creeped up to compensate.

 

[redflash]

I have a different direction to look at > I don't believe this is an idle issue at all.... I have a comet 30 and when I installed new springs ( different from stock ) ( by the way, the drum which you stretch the springs on is called the.... " Spring and flyweight assembly". The spring and flyweight assembly looks like you can install it with either surface down....That is not true...the bevel on each side is a little different. I thought they were that same, so I just installed the fly weight assembly the side down....that looked best. I was wrong the new comet 30 was constantly engaged....when I started the motor ( jacked up) the wheels would turn at speed. I recognized that the driver pully was tight on the belt...which made the torque converter engaged all the time.
I took the driver pulley apart and reversed the flyweight to put what I thought was the top side....to the bottom side, and voila it worked perfectly ever since......try reversing the flyweight.....that should fix the problema

Da Flash

 

[miniblazinbmx]

I have a different direction to look at > I don't believe this is an idle issue at all.... I have a comet 30 and when I installed new springs ( different from stock ) ( by the way, the drum which you stretch the springs on is called the.... " Spring and flyweight assembly". The spring and flyweight assembly looks like you can install it with either surface down....That is not true...the bevel on each side is a little different. I thought they were that same, so I just installed the fly weight assembly the side down....that looked best. I was wrong the new comet 30 was constantly engaged....when I started the motor ( jacked up) the wheels would turn at speed. I recognized that the driver pully was tight on the belt...which made the torque converter engaged all the time.
I took the driver pulley apart and reversed the flyweight to put what I thought was the top side....to the bottom side, and voila it worked perfectly ever since......try reversing the flyweight.....that should fix the problema

Da Flash

Im so confused by what you consider upside down as most of these are mounted vertical..

you got any pics of that you can share? not sure thats my issue but Ill look at anything before tearing this 40 series apart..

 

[madprofessor]

Check link below, scroll down to the printed info, about a page full titled "General Information" followed by "Maintenance". Doesn't address flipping the flyweights over, but does explain how the driver and driven mount opposite each other. Look at the diagrams also.
Comet 40 Series Torque Converters | Comet 44 Series Clutches (gokartsupply.com)

 

[miniblazinbmx]

Check link below, scroll down to the printed info, about a page full titled "General Information" followed by "Maintenance". Doesn't address flipping the flyweights over, but does explain how the driver and driven mount opposite each other. Look at the diagrams also.
Comet 40 Series Torque Converters | Comet 44 Series Clutches (gokartsupply.com)

Ive got the reverse spring in my driven.. so they are both being run outboard.

My driver doesnt fully disengage or smoothly. It acts like its binding up. I am going to recommend spending the extra $60 for Comet parts as these amazon and ebay ones are just **** can probably cant handle any motor with real power and torque. My 440cc is close to 30ft lbs, as opposed to a 212 which outputs 9-10.

 

[redflash]

what I mean by "down" is toward the motor ! Of course its verticle........down is toward the motor and up is away from the motor.
my point is to reverse the flyweight....its probably on bassakwards......mine was and it presses the bells and engages when you don't want it

da flash

 

[miniblazinbmx]

Thanks, Ill def pay attention to orientation when I get it off and apart, Wouldn't be the first time something made in taiwan was built wrong.

 

[madprofessor]

Go to link below, scroll down to a page full of text info, read it all. Then scroll further down to between the pictures of "Comet Driven Pulley Spacer" and "40 Series Driver Clutch Spring Set". There's a little chart there of clutch engagement rpm's with 3 different roller weights for both yellow and red springs. Raising the clutch rpm engagement range with simple parts swaps may be the way to go for you.
Comet 40 Series Torque Converters | Comet 44 Series Clutches (gokartsupply.com)

 

[miniblazinbmx]

Go to link below, scroll down to a page full of text info, read it all. Then scroll further down to between the pictures of "Comet Driven Pulley Spacer" and "40 Series Driver Clutch Spring Set". There's a little chart there of clutch engagement rpm's with 3 different roller weights for both yellow and red springs. Raising the clutch rpm engagement range with simple parts swaps may be the way to go for you.
Comet 40 Series Torque Converters | Comet 44 Series Clutches (gokartsupply.com)

You may very well may be correct, however I do need to get this thing functioning right first, If I cant find the issue and modify I prob wont use the part at all, Getting close to wits end with some of these pesky little issues.. I'll def try to repair what I have before buying a genuine Comet.

 

[redflash]

oops

 

[Usndemboyz]

Anyone recently have the same issue with idle engagement? Installed a new OMB warehouse 40 series with steel backplate and vendor supplied belt ( 203785A which is the correct spec belt per Comet chart ) on a new Duromax 440 and it engages on idle mainly because of the belt tightness. The TQ Conv is NOT engaging prematurely with the yellow spring, and all components are installed as per Gray Goat garage's helpful video. Idle has been lowered as much as possible on the engine also to help. I reached out to OMB and was instructed to change the driver springs, which is solid advice and to stay away from using a longer belt. But still, has anyone ever used a belt that was a little bit longer to avoid the pre engagement? The next belt size up is the 203786 and just about an inch longer, which IMO, should give a little more play and yet still engage when RPMs are given. Any thoughts or input would be greatly appreciated!