Torque converter help

[wfc]

Hi, I am new to this forum, spent a lot of time browsing through the last couple of days and must say it is brilliant.
Maybe some of you could assist me with some questions I have regarding the torque converter and gearbox I have recently managed to find. All I know about it is that it came off a 70's snowmobile, and seems to be extremely strong and durable. I am from South Africa, and bought it from a man who brought it into the country about 35yrs ago to build a gokart and never got that far. The gearbox selects forward, reverse and neutral, and it has a disc and caliper on for braking.

I am considering using it together with a Honda gx390 on an offroad gokart that I am building. I have no experience with torque converters or cvt's up to now. My question is: How do I determine how far appart to mount the gearbox from the clutch assembly pully? I know that it is determined to some degree by the belt, but the pully on the gearbox side opens up, and that changes the distance. Where do I start? Also does anyone know where I could find some more info on this setup? I am adding some pictures to show what I am talking about. Thanks for your help.

http://i484.photobucket.com/albums/rr208/wfcsa/DSC00184.jpg

 

[jr dragster T]

Your secondary sheive is stuck open, Or a badly worn belt. Belt should not sit that low. Belt cover should stick out of primary about 1/16"+

 

[wfc]

Hi, the belt is only that low because I pushed it down in there. Normaly it sits right out.

 

[jr dragster T]

Ohh ok.

 

[Jerryburger]

If you don't mind me jumping in, I'll try to help!
The center-to-center distance between the two pulleys IS deterimined by your belt (good guess!) and what you're shooting for is that the driven pulley is all the way closed, and the belt is snuggly in the groove, with a slight bit of slack around the driver (engine) pulley. You're aiming for a s much "tightness" as possible without causing the belt to move while the kart is idling. As far as alignment side-to-side goes, try to get a mental picture of the 2 extremes your pulleys will be in.... (I know this sounds funky, but plz bear with me) At LOW speed, the engine pulley will be just closing enough to grip the belt and the driven pulley closed. (That's the easy part to line up.) At HIGH speed, you'll need to fully spread the driven pulley (to see which direction the belt will get shoved and how far) and then close the engine pulley. I did a "from scratch" arrangement on one of my karts using snowmo pulley's, and the more time you spend on this the better results you'll have.
I ended up with what you see here... the orange pully is offset from the blue pulley by 3/8" to the left (viewed from the back of the kart). I don't know if your driven pulley is facing the right way or not, by the position of the helix and spring on it. Kind of hard to tell from here.
Hope that helps.

 

[wfc]

Hi Jerry

Thanks for the reply. I see what you are saying about getting the distance correct between the pulleys. Regarding the offset that may be required, I havent realy looked at it in that way. I will play around with the setup and see if it needs it. As far as the driven pulley is concerned, that is the way I got it when I bought the setup. It is not impossible that it is wrong! How would I determine whether its wrong or not? I can see from your pulley that mine is facing the opposite way though. I realy appreciate your input as I know next to nothing about these, but I'm hoping to learn enough to get it going
Be Blessed

 

[Kaptain Krunch]

One thing you want to consider is the RPM range of the torque converter, if it was off a snowmobile then it can handle about 8 or 9k rpm, and the average briggs or honda kart engine runs around 3500 tops, so you wont be able to use the full range of the torque converter, that is if it even engages before 3500 rpm.

 

[jr dragster T]

One thing you want to consider is the RPM range of the torque converter, if it was off a snowmobile then it can handle about 8 or 9k rpm, and the average briggs or honda kart engine runs around 3500 tops, so you wont be able to use the full range of the torque converter, that is if it even engages before 3500 rpm.

Change the weight's and ramp's.

 

[wfc]

Hi Kaptain Krunch,
You have me a bit worried here, the engine pulley is marked as "up to 9000rpm". You are right, I want to run it with a honda gx390 motor, and stock they run about 3800. I will be removing the governor and adjusting the timing to 6 degrees advanced with a free flowing header. I dont realy want to do more as I cannot change the rod. Dont realy know what rpm range that will leave me in.

jr dragster; how would one change the weights and ramps. Taking into account that I'm all the way over in South Africa and parts are like hens teeth over here?

Thanks for your input guys!

 

[Kaptain Krunch]

well I'm sure running your honda at 9000 RPM's would not be very good for the engine, or your health...I have never taken apart a toque converter, i've seen how they work and understand that, just haven't worked with them a lot. But I'm sure Tyler can help you with the adjustments.

Another option would be using a snowmobile engine, Although i doubt you'll find one in south africa...But if you can get a small 295 twin, like they used in the older Arcticats, you would be in luck.

 

[wfc]

I actualy do have a two stroke at the ready, but it isnt off of a snowmobile..... It comes off of a yamaha yz490. I would rather have fitted the honda gx390 with the torque converter, as there is a gearbox as well, which includes a convenient reverse gear. There is that, and maybe the fact that the thought of the yz490 on the cart scares me just a little The kart is strong enough to handle it though. Well, lets see if anyone has some good advice that may save me from the yz and bring the honda back in the picture??

 

[Kaptain Krunch]

I actualy do have a two stroke at the ready, but it isnt off of a snowmobile..... It comes off of a yamaha yz490. I would rather have fitted the honda gx390 with the torque converter, as there is a gearbox as well, which includes a convenient reverse gear. There is that, and maybe the fact that the thought of the yz490 on the cart scares me just a little The kart is strong enough to handle it though. Well, lets see if anyone has some good advice that may save me from the yz and bring the honda back in the picture??

passing up a shifter kart with a 490 2 stroke?

Man i'd be on that like white on rice, or a fat kid on a ham sandwich...Oh well, I'm planning on a suzuki dr 100 kart this summer, wont be fast but its a 4 stroke so low end torque will be nice.

 

[jr dragster T]

I cant tell you exacyly how to change the weight's as I never seen or even worked on a clutch looking like that. But I assume it's a ramp and roller clutch. Remove the top cover and look inside. You will see 3 or 4 "Ramps" (Appears to be 3 from pics) And you will see 3 or 4 arms with a roller on the ramp and 2 weights on each arm end. Ramps and weights controll how fast the clutch shifts out. Finding/Getting parts where you are might be hard.

 

[wfc]

Hi Jr dragster. I believe you are correct in describing the workings of the clutch. Would more weight on the rollers make it shift quicker? I am adding a photo so you can have a look.

Kaptian Krunch you may just twist my arm there with the yz motor. Here is a picture of it. I just won the bidding for a carb on ebay, should have it in a couple of weeks, otherwise the motor is in good condition and ready to go

Lastly here is what I have so far.

Regards
WFC

 

[BradenM]

Wowee. Good job mate!

 

[Kaptain Krunch]

Nice job, thats looking great, now imagine that frame as a shifter kart, geared for a top speed of around 60 mph and still having the torque for whatever you need...That bike engine would give much better performance than your honda...but hell if your not gonna use it, I'll take it :biggrin5:

 

[wfc]

Hi Kaptain Krunch, I will propably go with the bike motor.... seeing as I already have plans for another kart where the honda will work fabulously! I will be mocking up the mounts for the bike motor somewhere this weekend. I still need to sort out the fuel, brake and clutch cables and a few ods and ends, but at least its getting there

 

[Kaptain Krunch]

Hi Kaptain Krunch, I will propably go with the bike motor.... seeing as I already have plans for another kart where the honda will work fabulously! I will be mocking up the mounts for the bike motor somewhere this weekend. I still need to sort out the fuel, brake and clutch cables and a few ods and ends, but at least its getting there

Nice, that things gonna be a beast, im going to work on taking my dr100 engine out of the bike and making the motors mounts once my garage warms up, post some pics when your done with the mounts, im planning on using some old angle iron from a bedframe. A suggestion for the brake and clutch would be to put them right next to each other, and connect them so you can push just the clutch without the brake, but when you push the break it always pushes in the clutch. With that setup breaking will be easier and you can drift a lil bit too. Also what im doing for shifter linkage, since its right behind the seat im going to use some bike chains and jackshafts to move the shifter up on my left side (plus im gonna have a kickass golf ball knob), so that its easier to shift.

 

[jr dragster T]

Yes more weight on the arms makes it shift out faster. BTW Thats a very solid clutch you have!

 

[wfc]

Nice, that things gonna be a beast, im going to work on taking my dr100 engine out of the bike and making the motors mounts once my garage warms up, post some pics when your done with the mounts, im planning on using some old angle iron from a bedframe. A suggestion for the brake and clutch would be to put them right next to each other, and connect them so you can push just the clutch without the brake, but when you push the break it always pushes in the clutch. With that setup breaking will be easier and you can drift a lil bit too. Also what im doing for shifter linkage, since its right behind the seat im going to use some bike chains and jackshafts to move the shifter up on my left side (plus im gonna have a kickass golf ball knob), so that its easier to shift.

I will look into the setup you are explaining here Kaptain Krunch, thanks. By the way, hope your name didnt come about due to your riding style??