72cc Stock Setup Concerns

[Rancher1]

Yea I think I'm going to build a positive pressure setup. I just noticed I have a small exhaust leak at the header. It wasn't there before but I've been pulling it apart a few times.

I have been considering a mild pipe. Like a Wildlion, SEF Black, or a Technigas. PGs are good values but too loud for me. A top pipe used to be the Arrows years ago - don't know if they're still around. Still kinda loud for me.

How does the 24mm Polini sound compared to a 28mm Keihin? I only have experience with the 28mm and 30mm with Uni pods and from what I remember it was pretty loud.

[ped]

Hi. I'm running a 24mm with a pod filter on a 50mm Bbk and it's ridiculously loud.
At night I have to start the bike a block away so I don't disturb my neighbors. lol.

I'm also running a stock carb with a Corsa, and
Stock carb with Contesta.

Will soon be running a Corsa with 21 mm oko. Hopefully it will be quiet?

[Dbroogs]

so it sounds like we have air leaks. What are other possibilities of high temps? could it be unusually high compression?

For the air leak, seeing as i dont want to spend $30 to buy the parts just to test if i have an air leak, what should I all do when i take the engine apart and put it back together. the copper spray for the gaskets seems like a good idea. Should I buy new intake gaskets? I am assuming to fix the issue is just to be more meticulous when putting everything back together? Basically my question is how to fix an air leak if you don't
know where it is coming from.

[ped]

Hi. don't spend a lot of money just get a bicycle pump with a gauge. pump up to 6 psi. Plug the exhaust make a plug for the intake .Squirt a little dish washing liquid and water with a spray bottle to find the leak

You can buy gasket paper and make your own gaskets. works for me

[Dbroogs]

i think a 21mm carb and pod will be my purchase if i get a new carb

[Dbroogs]

I sprayed the copper gasket stuff on my gasket and also think I found my problem. One of my exhaust studs wasn't screwed in far enough so the nut ran out of thread when tightening the exhaust. There was a small gap and I could see a little residue on the exhaust flange. Hopefully fixing that and the copper spray will do the trick

[Rancher1]

What's the practical performance difference between the regular polini carbs, cp, and evo?

[johnny248]

I ran my Taiwan 72cc bbk with a stock carb with (i think) an 89 or 98 main jet, different reeds, and the oil pump zip-tied open all the time. Other than that, I had a different variator and a Tecnigas Next R pipe. It ran fine for the time I had it.

The Tecnigas pipe wasn't very loud, and actually provided very good performance on my 72cc kit. I just don't think it is meant to me a 11k race pipe or anything. It's available for sale if you are interested.

[Dbroogs]

Would getting a new carb even benefit me at all with the stock exhaust still? I know tuning and everything would be easier as well as more air and fuel flow. Doesn't the muffler limit me here. I do not want to spend that much more yet, or any, this is just more for future purchases. Will probably mess with it more when I am out of college and making a decent living.