Go-Kart will run fine then run at half speed.

[SpeedDemon1990]

I recently got a new clutch on my go kart, which is reaching the end of it's life span, and I was driving it today full out and it was running great. Then, I turned it off and started it a second time and it went about half speed and never got up to full speed. I gave it an hour or two rest. Tried again, ran fine. Turned it off and retried it, wouldn't run worth crap. Could this be an overheating issue?(It's 90 degrees where I am right now.) Or, is something going bad in the engine where is won't get up to full speed? Sometimes, it will just not go, like something is not grabbing. I have no idea what to do. Please help. Thank you.

 

[OzFab]

When you noticed the speed difference, did you notice a change in the sound of the engine? If the engine runs the same in both instances, it's definitely the clutch; if the engine was different, well, then you have bigger problems...

 

[SpeedDemon1990]

The engine sounded weaker than normal. Seemed like it was running low on power.

It almost sounded like it was sputtering trying to get up to speed, too.

 

[OzFab]

Please use the edit button as opposed to multi posting...

Well, it's definitely an engine problem then; when was the last time you
-cleaned the carb
-checked/replaced the spark plug
-checked/replaced the oil?

 

[SpeedDemon1990]

I got a new carb put in a couple months ago, new spark plug was installed, and I actually just replaced the oil before this all started happening. Any chance this could be a piston problem? Or, piston ring problem? It starts out fine(feels like it has full power), but after about 5 minutes of driving it, it feels like the engine loses power.

 

[OzFab]

Any chance this could be a piston problem? Or, piston ring problem?

Is it blowing lots of smoke? If not, it's not likely to be rings. Besides that, worn rings usually work the other way around, engine starts off weak &, as everything heats up & expands, you gain power...

This one has me stumped, let me think about it for a bit...

In the meantime, if anyone else wants to jump in...

 

[landuse]

I have no clue...sorry

 

[SpeedDemon1990]

It is not blowing any smoke. I actually just took it for a two runs and the first run it ran fantastic. I turned off the go-kart for probably 10 minutes after that and then started it back up. I'd press down the accelerator and it would rev up and down and not go anywhere(belts are new, sprocket is new, clutch is new). This is a common theme. If i turn it off after it's first run(when it runs fine), it does not want to go for a second run.

 

[Hambone]

Is this a torque converter? The bushing could be worn out and cause the clutch to not be able to fully open.

EDIT: probly not, just thought I'd throw it out there

 

[landuse]

Is this a torque converter? The bushing could be worn out and cause the clutch to not be able to fully open.

EDIT: probly not, just thought I'd throw it out there

Post some pics of what the clutch looks like when it is giving you a problem

 

[SpeedDemon1990]

It is indeed a torque converter. I'm going to try to post a video of what it is doing. I press down the accelerator completely and the RPMs go up but it takes it about 5-7 for it to start moving after that.

 

[99thwondah]

Is your tc backwards? Dismantle and lube it could be getting stuck in a position once hot causing your issue from trying to expand on that side, also in the last pick your belt looks off alignment.

 

[SpeedDemon1990]

Which part of it looks backwards to you? It would be interesting if it was backwards because it ran great earlier today. I would think it would not run good at all.

 

[99thwondah]

Don't take my word for it but always seen clutch side facing out wards, hard for you to do any changes/take it apart with it facing that way. You should feel some jumps when it shifts...to test engine raise rear wheels off the ground remove belt let it go with no load careful if not governed? Few revs, Does engine run good? If so engine is not culprit, engine stumbles like before check your spark color when hot.

 

[Hambone]

That's a 40 series system. The driven clutch is supposed to be facing that way. On the 30 series systems the driven would have the spring facing outward.

I'm not sure of the 40 series has a bushing like the 30 series, but check to see if the clutch is pushing the belt all the way to the top at full rpm

 

[landuse]

Is that what the TC looks like when you are having a problem. I am refering to the belt position

 

[SpeedDemon1990]

Yes, that is what it looked like when i was having problems with it. I drove it today and it ran pretty well. however, when it was idling, it would roll forward, which I believe indicates a clutch problem, but i just got a new clutch put on. I don't get it.

 

[landuse]

Yes, that is what it looked like when i was having problems with it. I drove it today and it ran pretty well. however, when it was idling, it would roll forward, which I believe indicates a clutch problem, but i just got a new clutch put on. I don't get it.

Are you sure you have the correct belt?

 

[SpeedDemon1990]

I'm pretty sure. It was hard finding the belt, but it ran great until recently. Actually, I've driven it 3 times today and it has run very well. It seems like sometimes, the kart will run great and then sometimes it just doesn't want to go. When it doesn't want to go, it sounds like the engine is missing a lot. I did have one situation today where I stopped for a bit to fasten my seat belt and I pushed the accelerator and it would barely go. Then, something grabbed(belt or whatever) and it went fine. One final note, white smoke does come out of the exhaust. Not bad or all the time, but mostly under acceleration and idling.

 

[99thwondah]

Check your spark plug sounds like deposits may be cutting your spark. Wire brush it when engine is missing or you see smoke. Read your plug then as well, could explain why your engine does great for a while then decreases performance.