Slugglish K-Star

E50, Transfer Matched 70cc K-star kit, hi comp head, Tecno Circuit, 3 shoe aftermarket clutch with kickstart springs, 15 SHA with stock filter, 16x45 gearing ( Not quite sure on the rear gear). The bike tops out at around 40 mph. I've seen tuning spreadsheets and I should at-least be at 45 mph. What am i doing wrong? I've tuned the clutch and gearing for better take off but rather have low-end torque. I had a 15 bing previously on it but couldn't tune/jet it quite right. My list of parts that I have that i could use is a Stock 2 shoe clutch with blue springs, 15 bing, 14 and 18 front gear. What do you guys suggest? Thank You

Re: Slugglish K-Star

sookia sookia /

eh, i've had a very similar setup, kstar, proma, 3 shoe clutch with blue springs, 15 bing, treats cdi and was topping out at 43. I weight 210 at the time though.

switching to an estoril got me 52 on flats with *ok* low end

Re: Slugglish K-Star

It's probably the gearing holding your top speed back

Re: Slugglish K-Star

It's gearing. Go 18x45. That carb is a bummer on that kit and is holding you back significantly as well.

Re: Slugglish K-Star

Dirty30 Dillon /

^^^ What Andy said.

I had a super similar setup, 70k/tecno/14bing/18x45/2-shoe blue that would do 45 easily, a bit more if you had a tail wind.

Re: Slugglish K-Star

Probably Fred /

Stock Gearing too low. 18x45 =16x40 will get you 43-44 mph .

17x40 will get you 46-48mph but more clutch tuning may be needed. If your clutch is tuned good enough then that doesn't really matter if your at stock gearing or 16-17x40 you still will have good take off with a circuit pipe .

You will have a longer pull taking advantage of your only one gear engine.

Re: Slugglish K-Star

get a 20 mikuni bolt on with a new intake, also check your clutch cover on the inside of it and make sure nothing is rubbing against it. Then while you have it off, spin your pedals and make sure i all looks and sounds good inside there. Also have you checked your bearings in your tires or at least repacked them. My 17/45 k-star / extroli with 20 mikuni does 52 on flat with 250 pound rider with tons of low end power.

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