Need help with 2 problems on my BKS Kart

[BKS212]

So I have what I've identified as a BKS Kart.

When I got it it had a briggs on it with a 30 series TC and a 72 tooth sprocket, and 10 tooth jackshaft. 20X11x8 rear wheels. With mechanical disc brake.

I ve done quite a bit of work to it.

Now has a hemi predator 212 with stage 1 upgrades as well as other free mods. Also put a new driven unit on, New driver flyweight, cover, and slined hub.

The two problems I'm having are #1 the TC is shifting into high range too soon and staying there even when slowing down, letting off gas, going around corners. So it causes the engine to bog down. Its like your driving a car, dump the clutch, wind out 1st gear, then accidentally go into 4th instead of 2nd, just boys right down.

This didn't start until I decided not to leave well enough alone and get a new TC belt, and the yellow torsion spring.

My old belt was 11/16th wide instead of the 3/4 it should be.

I had the green torsion spring in the #2 position (when i got it it was in the #1)

It ran very well topped out at 50mph, and did decent up steep grades, could soon donuts on a dime.

So I put the new belt on, and the yellow spring in the number 3 position thinking it would be even stronger and hold the shift longer.

Wrong.

It actually was slower up grades now, but same too speed.

Changed to the #2 position, a little better but still not as good as the green spring in #2 and old belt.

The new belt was/is getting chewed up too.

So I tried to put the green back in, couldnt, ended up damaging the old driven too much.

So ordered a new driven. It came with the green spring in the #1 position. It ran decent, but still not as good as the old belt and #2 position .

Still not satisfied I went to the #3 position. Now it's even slower and shifting too soon.

I noticed my front driver and spooned hub were wore out and had play.

Orders both new, problem still exists.

Idk what is up with it. Wether its the driver or driven unit. Or if the flyweight is messed up. Or I have the driven preloaded wrong or what. And why it's chewing the belt up. Used a straight edge on them, they're equal, so don't know why Its chewing it up. At a loss. Which I had just left the old belt on and old driven and spring. It looks like the driver clutch isn't closing up fast enough and is opening too soon.

My other problem is, I have a breather filter on the valve cover and it's just spitting oil out. Covering my air filter, which luckily I have a pre filter on. Changed the oil today on it, 10w30 Mobil 1. Still puking it out the breather. You can just tap the throttle and see it bubbling in the breather. Even had some smoke before I changed the oil coming out the breather. The engine turns about 5500 I think based on a go kart speed calculator I found With my 20 inch tall tires, .90 overdrive TC, 72 tooth sprocket, 10 tooth jackshaft, and GPS verified 50mph with the throttle stop all the way out and the zip tie trick in the gov Spring I found on youtube.

Sorry for the long winded post, but wanted to help others rule out things I've already done/tried to remedy the situation.

I also have a YouTube video of the engine and kart running when it ran good if anyone is interested just to see how it did perform.


Engine
https://youtu.be/zKH4C-WC890

Kart being ridden
https://youtu.be/Z9avWSo2WWE

 

[KartFab]

do you have the genuine comet or the chinese belt? If its genuine comet it will be printed on the belt. The chinese ones work, but dont grip as easily as the genuine comets.

Also, just reading about your gearing, have you tried an 8t or 9t jackshaft sprocket instead? Sure you will lose out on top end, but you may get more torque out of it.

you can get a type c 8t/9t at ombwarehouse.com just search in their sprockets, grab the part number, hop on ebay and get it haha. ebay is cheaper.

 

[BKS212]

I'm not home to check right now, but it was this exact one:

http://www.mfgsupply.com/203591a.html

I did the proper measuring too. Center to center distance, and the driven unit diameter.

Was also same part number as one that's on it.

I could drop to a 9 or 8, but I don't think that would correct the issue of it shifting into high gear too soon, and not coming out of high gear.

I think I've seen your videos on YouTube. The manco dingo with the 13hp gx390 that does wheelies. Sick kart!

Got another were working on similar to yours, black dingo, 8hp briggs, 40 series TC.

 

[KartFab]

Hmm ....... Have you made sure you pre wound the springs and that the cam is on the correct side of the wear tabs?

 

[Half-breeder]

... sounds pretty much like my setup minus the gearing and 20"wheels... (modded 6.5, TC30, 50mph...)

I agree w/ tryin to change the gearing slightly... 1T at the JS, can make a huge difference (under gearing/rpms like ours) w/ the TC engagement time(s), asfar as it not disengaging and it bogging your engine... "my" guess, is the driver sheave that slides in/out, is getting caught/wedged on the copper/brass bearing ring (hopefully you have one...). The none Comet TC's drivers tend to 'not' hold up too well to 5k RPM's at the kinda gearing that we use.

The belts getting eaten up are possibly due to sheave smoothness. Mine were gettin eaten up on a regular, till I took 400grit sand paper to the sheaves... after I switched to an original Comet I noticed the belt wearing after wire brush cleaning... after 400grit... practically no wear now. You may wanna ENSURE there is NO/0/zip/zilch, play in the 2 pullies, on their shafts. 1/8" off and there wear is quite heavy.

Just an FYI... you/I/ppl like us are using the 30series AT their limit(s), and then some...

The oil spitting is a mystery to me aswell... I think slanting the mount of the engine to 15* 'helps' but not sure if it's a 'fix'... have yet to try it. Im pretty sure due to the faster than factory setting, RPMs... the oil is getting slung further/harder than stock... so my hypothesis is that the 15* may deflect the 'over' slinging of oil up and out of the valve cover breather via angle and gravity...

 

[BKS212]

Definitely on the correct side of the cam. Looking at it the point of the outer driven precedes cam button. I also watched numerous videos on preloading the driven.

I do have the brass sleeve the belt rides on, I didn't think about the sheave the flyweight pops into the one that moves in and out could be catching on that sleeve.

Every part is genuine comet other than maybe the belt, have to check on that still.

The oil pushing through the breather, I may pop the cover off and check the valve lash. Make sure seals and everything are good too.

Just sucks that I spent the money and put the time in to make it work better, and I seem to have went backwards.

Don't fix it till it's totally broke may be my new philosophy on this thing once I do get it right again. Haha.

 

[BKS212]

Update:

readjusted the valves to .003. The exhaust was quite a ways off, intake wasn't too bad.

Kart still pushing oil out the breather.

took apart the drive clutch and took a rattail file to where the spline goes in and out, goes right through nice and smooth now.

Cleaned up the end of the inner driver sheave, had some wear and rough spots, and cleaning the brass bushing up some.

but it still is getting stuck in high gear. You can let off the throttle, and it won't come off high gear at all not even the slightest bit, until you are at a complete stop.

I drove it around our little track in our yard down the straight away, and let off the throttle into the corner, didn't touch the throttle once, and watched it all the way through the corner and the driver clutch never attempted at all to shift into low gear.

I d k what is going on.

 

[Half-breeder]

May need a new brass ring. Try running it w/out the ring n see if it still sticks.

 

[landuse]

Update:

readjusted the valves to .003. The exhaust was quite a ways off, intake wasn't too bad.

The intake and exhaust valves are not supposed to be the same AFAIK. Check what both yours should be

 

[BKS212]

Everywhere I've checked says .003 for valve lash for the I/E. Someone correct me if I'm wrong.

I didn't try to run it without the brass ring, I'm sure that would chew up the belt more.

I took apart the front driver clutch and noticed on the moveable sheave, that the flyweight snaps into, has some major wear on it and stress cracks. So I'm thinking that was causing some issues.

So I've ordered a new front driver moveable sheave, and a brass sleeve. Hopefully that corrects the issues.

As far as the oil being pushed through the breather, took the breather off, and revised the tube going to it with a larger diameter one. And zip tied it a little more vertically. Hoping that helps, but haven't ran it enough to tell yet. Probably won't until new torque converter parts come in.

 

[landuse]

Everywhere I've checked says .003 for valve lash for the I/E. Someone correct me if I'm wrong.

Hopefully someone helps us out here

 

[Poboy kartman]

It's counterintuitive to have identical clearance on both...because the exhaust valve usually has more clearance..(so it can expand with heat).

But I've heard those lash settings quoted more than once....I haven't checked, but I think it's correct for that engine.

 

[BKS212]

New torque converter parts were the ticket.

New inner moveable sheave, and brass ring.

Works great now.

But, still pushing oil like crazy out the breather and running pretty hot.

May start a separate thread for that issue.

Motor is a harbor freight 212cc hemi.

Has a stage 1 kit from omb which is air cone, jet, emulsion tube, timing advance key, and header pipe.

I also cut every other fan blade off, and took governer screw out.

 

[Half-breeder]

Define... "... took governor screw out."... ?!?

 

[BKS212]

In the governer linkage on top of the engine is a governer screw to limit throttle. Maybe throttle stop is the better term.