No low end power on conversion

JewelryMonk · Post by **JewelryMonk** » Wed Jun 24, 2015 4:02 am

After my 70cc upgrade and Prima pipe, I put a 19mm Malossi carb on this week with a scooterworks racing air filter,
it had a 80 jet in the carb from the start. I changed jets 5 times and ended up with a 118 jet in it.
It still has no low end, bogs down quite a bit.... no take off..., but goes good at the top end.
Plug finally looks tan instead of white.
Also changed slider weights to 6.0g and stronger spring.
I have to figure out the low end....
Any ideas?

babblefish · Post by **babblefish** » Wed Jun 24, 2015 5:54 am

You've been playing around with the top end mixture by changing the main jet, but have you tried richening the low end via the idle screw or the midrange via the needle jet?

BTW, repeating your question in three different threads might upset one of the mods. Just saying.

JewelryMonk · Post by **JewelryMonk** » Wed Jun 24, 2015 12:17 pm

Thanks and sorry for the repeat questions.
I have adjusted the idle mixture but not the needle jet. Might have to try that next.

avescoots1134 · Post by **avescoots1134** » Wed Jun 24, 2015 12:57 pm

You need heavier clutch springs. You'll probably never get too much bottom end with a Prima pipe, it's for top end HP.

JewelryMonk · Post by **JewelryMonk** » Sat Jun 27, 2015 9:20 pm

I put in a yellow spring that came with the stage 2 conversion kit. I think I read it is a great 1500 spring.

babblefish · Post by **babblefish** » Sat Jun 27, 2015 11:17 pm

JewelryMonk wrote:I put in a yellow spring that came with the stage 2 conversion kit. I think I read it is a great 1500 spring.

I think avescoots1134 was talking about the clutch springs, not the torque spring as you are referring to. There are 3 small springs in the clutch which depending upon their stiffness, determines at what RPM the clutch starts to engage and the scooter starts to move. He is suggesting that heavier/stiffer springs be installed to allow the engine to rev up higher in the RPM range where your new pipe has moved the peak torque to give a better take-off performance.