early 70s sl 338 will not rev under weight

[modded kart]

Hi figured out my motor was off an sl338 not entycer as I was told by the previous owner. I now have this motor on a go kart the engine starts fine and seemed to be in perfect working order until today when I put a belt on it. (Came with a snapped belt). When I attempt to launch the engine will barely rev it has total power loss. Once the clutch begins to engage the motors rpms become limited by it. Anyone got any guesses? The cluch and drive are all off of the snowmobile up to the axle.... pic is before I mounted gas tank and put new air filter and belt on

 

[Maim]

i would start by cleaning the rollers and slides in those clutches. the clutch looks like they might be a bit gummed up with corrosion.

 

[modded kart]

clutch

I oiled up my clutches with gear oil and wd40 I got about ten minutes of ride time during which I felt like the cluch was slipping way too much followed by the drying up of the oil setting me back to square one. Is there a special clutch oil or adjustment I can use to fix this problem permanantly?

 

[shaggyzr2]

You don't oil clutches

 

[modded kart]

I only oiled the shafts and internal components, nothing that directly contacts the belt. It was sitting for 3 years before I bought it so it was most likely gummed up. Now the components move much more smoothly but I have this inabilty to get the rpms I need. Engine revs right up without belt attached and clutch seems to move as it should.

 

[Maim]

Might need a new primary spring but it still needs to be disassembled and cleaned. Lube just gums them up worse.

 

[modded kart]

Might need a new primary spring but it still needs to be disassembled and cleaned. Lube just gums them up worse.

Ok, thanks for the advise I appreciate it, I'm not a big sled guy so I'm having a rough time with this thing. I was trying to avoid dissassembling the clutch but looks like i got no choice. Also just wondering how ill be able to tell if the spring is shot. I am currently able to move the clutch bell towards and away from the engine with about a quarter inch space before it hits the spring, so the spring is possibly compressed from years of use. But like I said I'm not a sled guy, so I don't know how things should look when they are working correctly, it makes it much harder to work on.

 

[shaggyzr2]

I only oiled the shafts and internal components, nothing that directly contacts the belt. It was sitting for 3 years before I bought it so it was most likely gummed up. Now the components move much more smoothly but I have this inabilty to get the rpms I need. Engine revs right up without belt attached and clutch seems to move as it should.

You never oil a clutch, just keep them clean!

 

[modded kart]

Just cleaned it all up, the gunk inside the clutch was horriblly thick, I soaked it in carb cleaner and cleaned it up nice. My first test drive had way better results I really appreciate the input from everyone who helped me out still is a bit rough but I'm almost positive its my engine tuning now. Thanks and I'm sure this bucket is gonna throw somethin else at me soon so ill probly be back for some more good advice sometime soon.