Help tillotson 212 stage 2 with very little low end

[mdramos530]

Help! I added a stage 2 kit from gps to my tillotson and it runs but now it has no low end torque. It won't even take off when I'm sitting on the kart. I don't know what I did wrong. Please help

 

[karl]

Well the camshaft you installed reduces low end torque.

It might just need steeper gearing to take advantage of the increased power
at high rpms, and/or higher engagement speed of the clutch, think 3k stall
instead of factory 2200rpm.

What have you done with the carb? GPS advises at least a 22mm mikuni carb

If your still running a factory, did you at least re-jet it?

 

[mdramos530]

Hey thanks Karl,
I have upgraded the carb to the 26mm gps mikuni style carb. Do you have a clutch that you would recommend for this engine?

 

[madprofessor]

karl, I appreciate your faith in humans. If he means it literally instead of metaphorically won't take off when sitting on it, then I have to believe he messed something up that has nothing to do with a 2nd stage upgrade kit. Failure to produce locomotion is in the drivetrain, not the horsepower.
mdramos, want my best off the cuff thought? If the motor runs and the drive sprocket doesn't turn, either the clutch is free-spinning on the crankshaft output (no keystock in the keyway), or the clutch got reassembled incorrectly.

 

[mdramos530]

I checked the keystock on the clutch and all was good either way it sounds like both of you guys agree that the clutch is the issue. Any recommendations for a good clutch for this setup?

 

[madprofessor]

recommendations for a good clutch for this setup

Only one that I'd recommend for it.................Folks call it a TC, or call it a CVT.............. That's a Torque Converter, also more accurately called a Constant Variable Transmission. In other words, common centrifugal clutches burn up, and uncommon expensive ones still can't provide the low end torque of a belt-drive configuration of a driver (acts as a clutch) and a driven (also a sort of clutch). Even the cheap Chinese ones can do a good job, but with a single caveat............Throw away the belt that comes with it, and use a genuine Comet belt instead. I'll attach some links for you of a full TC/CVT setup with a backplate, and the GKS site for choosing a Comet belt.
30 Series Torque Converter Go Kart Clutch kit 3/4 inch 12T #35 Chain (jeremywellindustry.com)
Comet Torque Converter Belts | Go Kart Drive Belts (gokartsupply.com) .............NOTE: Read every bit of the text at the top of this link page, then scroll all the way down to the bottom of the page, and read every bit of that text there (about twice as much as the top).

 

[mdramos530]

Only one that I'd recommend for it.................Folks call it a TC, or call it a CVT.............. That's a Torque Converter, also more accurately called a Constant Variable Transmission. In other words, common centrifugal clutches burn up, and uncommon expensive ones still can't provide the low end torque of a belt-drive configuration of a driver (acts as a clutch) and a driven (also a sort of clutch). Even the cheap Chinese ones can do a good job, but with a single caveat............Throw away the belt that comes with it, and use a genuine Comet belt instead. I'll attach some links for you of a full TC/CVT setup with a backplate, and the GKS site for choosing a Comet belt.
30 Series Torque Converter Go Kart Clutch kit 3/4 inch 12T #35 Chain (jeremywellindustry.com)
Comet Torque Converter Belts | Go Kart Drive Belts (gokartsupply.com) .............NOTE: Read every bit of the text at the top of this link page, then scroll all the way down to the bottom of the page, and read every bit of that text there (about twice as much as the top).

Thanks so much I really appreciate mad professor and Karl's help y'all are great

 

[panchothedog]

Other factors to figure. How tall are your rear tires, and if you can't measure them, just post the numbers off of the sidewall. Also tooth count of your axle sprocket and of the sprocket on the clutch. This is important information on determining if you need a torque converter or not. They work fantastic. I have them on all 4 of my karts.

 

[Willie1]

Going to mention it since no one else has.

Are you SURE that you installed the new cam correctly? It would probably still start with the cam 1 tooth retarded but have extremely poor take off.

 

[mdramos530]

Going to mention it since no one else has.

Are you SURE that you installed the new cam correctly? It would probably still start with the cam 1 tooth retarded but have extremely poor take off.

Hmm it's worth taking a look to make sure thanks!

 

[mdramos530]

So the cam was definitely retarded by a few teeth. I fixed it but now I can't pull start it. I did also get the head milled down slightly. With the spark plug out obviously it turns fine.

 

[redflash]

That's probably Valve adjustment. These engines are pretty sensative to accurate and correct valve adjustment.

Da redflash

 

[mdramos530]

That's probably Valve adjustment. These engines are pretty sensative to accurate and correct valve adjustment.

Da redflash

Just to be sure, your saying I need to adjust my valve lash?

 

[panchothedog]

What are the valves set at? They should be set at .003" , especially the exhaust. If not you are not getting the full benefit of the compression release,
which makes it kick back and hard to pull start. When you set the lash make sure the valve is COMPLETELY closed. Pull the engine over several times watching the rockers to familiarize yourself when the compression release moves the exhaust valve. As soon as it relaxes that is the time to set it.

 

[redflash]

what the dog said...........
Da redflash