RH 70cc kit problems

okcgravity · Post by **okcgravity** » Sat Aug 23, 2014 5:12 pm

Hey guys, I've been having a problem with a Prima 70cc kit and figured I would check here for advice. I have done some searches but not found anything exactly what is happening to me.

Here is what is on the bike right now.

Prima 70cc
Prima exhaust
moved up to a 19mm carb
95 main jet,
stock idle jet.

The problem is power. I have to use the choke to start the bike, hot or cold. Then when first starting out the bike is great, outran my friend from 0 to 40 on his LX150. Tops out around 50-55. But then it starts to run out of juice, it will slowly come all the way down to 35mph while WOT. If I stop at let it idle for 45 sec to a min it takes off like a bat out of hell again. If I am bogging down and stop, then immediately start off again "like a stop sign" then the take off is horrible, way slower than stock. It almost acts like I am running it out of fuel, then stopping and the bowl fills back up.

Would love to know if anyone else has dealt with this problem, or has any ideas on what to try next.

Thanks guys

lovemysan · Post by **lovemysan** » Sun Aug 24, 2014 1:30 pm

It sounds under jetted. I recommend a 98-105. Do not ride it until the jetting is correct. Is the air box stock and un modified?

agrogod · Post by **agrogod** » Sun Aug 24, 2014 8:51 pm

Did you 'tune' your carb? When going up to a 19mm you have to adjust your idle and mix settings for your ride. Takes some work but if you know an old time mechanic that has dealt with carbs before it will take no time at all.

jasmine12 · Post by **jasmine12** » Thu Sep 25, 2014 10:16 am

I don't know. But if that is all they last, then I would guess they have already been replaced once before me.