Very new at this

Fizzbane · Apr 4, 2010

Ok. For starters I am extremely new to the whole Bike motor thing and damn do I love it. My friends totally dig it. But I have a few questions...

For reference I have a Grubee skyhawk 66cc (Gt-5) which i bought from "Gasbike" which is also "Kings..." It is completely stock atm. Threw it on a cheap lil bike to test it out and will soon be swapping it over to a fixed/tuned up old mountain bike. I have run 1.5 tanks of gasoline through my engine (1st at 18:1, 2nd tank at 24:1) and am assuming my bike is past break in? correct me if im wrong.

I want to have a bike that can give me enough torque to pull me straight off the line (I'm 170lbs) because currently I am not getting enough power out of it to do so. Also, i would like to hit roughly 50km/h - 60km/h (30mph - 40mph) as a top speed. Currently i only get 40km/h (25mph) at most. I have a 44T sprocket.

My bike seems to bog and seems almost overloaded at highspeeds. I'm not really engine savy but i know it doesnt sound right. Also extremely slow to pick up speed.

I have looked into getting a SBP exhaust and the CNS racing carb as well as a 36T sprocket and I will purchase these items. (unless there is a better option suggested to me, *cough* better toothed sprocket?*cough*

I am wondering if the CDI or magneto should be replaced. I have read on the forums that basically plug wire replacement is a must as well as a new spark plug but i am uncertain whether the CDI itself needs to be replaced.

Another question i have is how tight should the plug boot be on the spark plug? mine seems to be barely floating on it sometimes and that concerns me. is there a way to prevent this?

What spark plug is recommended? i was reading that the NGK iridium is pretty good. I may get that.

Also, what would be a decent fuel mixture if i do not want to do much servicing to my engine as i am NOT comfortable with taking it apart. Im currently looking for someone around here to help me clean up the intake and exhaust ports, sadly everyone either refuses to touch it or will charge me $100 an hour...

Thank you very much! I really appreciate any feedback or advice given. I'm a senior at Highschool and this is my main mode of transportation and i want it done up nice. Thanks.

silverbear · Apr 4, 2010

If it were me I'd start with what's simple and cheap and move on from there. Yes, it seems to me you should be getting better power than you are. Oil type and gas mix ratio is simple enough even if opinions differ. I like the opti-2 best at 100-1 even for break in. Second choice is Amsoil synthetic Sabre professional mixed at 50-75 - 1 for break in and then between 75 & 100 to 1 after that. Whatever you use, follow manufacturer's recommendations.
I like the new iridium NKG plug and think changing out the plug wire for a better one is a good idea. The cap should fit snugly and the other end should be screwed into the CDI securely. That's where I would start, knowing I had a good setup for delivering spark and the right fuel. In my experience the CDI either works or doesn't at all. With a new engine it is probably OK, but anything is possible I guess. If it still lacks power then it is time to fiddle with the carb. Look at the plug and see what color it is. White is too lean and black is too rich. Brown is good. So you can adjust the needle accordingly if the plug doesn't look good. There are lots of posts here on that subject. If it is still sluggish then someone here will have suggestions for you. Expensive fixes like shift kits and expansion chambers aren't going to help if the basic stuff is off. That's my opinion anyway. Someone else may weigh in with something better. In a nutshell, start with the simple and go from there to the more complex if you need to. I have a feeling you're going to find it is something pretty simple. Good luck.
SB

bluenosegoat · Apr 4, 2010

In my opinion after only 1.5 tanks of fuel you are not broken in yet. I think the manufacturer says like 500 km. I have noticed on my sons bike is still picking up some power after 240 miles. From new it has gained nearly 6mph. I wish I could find this opti 1 oil everyone talks about and Amsoil is not around here either. I use Valvoline motorcycle 2 stroke oil and no complaints, available at Checkers everywhere. For sure do the spark plug check to see if your needle is set correctly- can make a huge difference in four stroking at the top end. Silver bear is right as i see it, you have to get the basic's right before you just through money at it. With out a shift kit I dont see take off without pedaling as possible. I have a shift kit and pipe and still pedal a little to get it going. I weigh 175 and my non shift kit bike with a 41 sproket will do right around 35 ( I dont like raping it out though) with good torque to get it there, even pulling my trailer with a load. You'll get there!

Bikeguy Joe · Apr 4, 2010

I will add "not broken in" and "don't buy a CNS carb."
Also, "You are not going to be able to take off from a stand still, AND get 35 mph top speed from a 36T sprocket, unless you have a shift kit."

Fizzbane · Apr 4, 2010

Thank you all for the advice. I am going to pick up some better oil (i bought mid-grade stuff to start as i was fairly poor and REALLY wanted to run it) and i am using the most premium gas i can find in town, 96 octane.

With the CDI i have read that they vary widely in Ohms and was just wondering if that was my issue. I will try out the other things before i swap out the CDI tho.

Ok, let me start here and say I am not extremely mechanic savy (i can get by but would not say im good or anything). I have read it over and over in the forums and I truly do not understand what the carburetor needle is or exactly how to fiddle with it. I am pretty sure most of my power issues are gas/carb related but would someone mind either showing me (pics rock!) or pointing me in the right direction? That would be MUCH appreciated.

Bike motor is not broken in, Gotcha.

Ok, Shift kits are a lil expensive so i will leave that for a lot later (if i get one). Would a centrifugal clutch help solve my no peddle start up?

I will add "not broken in" and "don't buy a CNS carb."

Why is a CNS carb a bad idea?

Fizzbane · Apr 5, 2010

I just took my entire bike apart. a mounting bolt snapped clean off and i gotta drill and tap to get it out now. I also purchased a new bike to throw my motor on so I guess it was time to take it off anyways.

Should i replace the stock intake manifold? Im not too comfortable with welding or things like that. But purchasing one is a welcomed option.

I now have read about the CNS carb and apparently its a hassle to get running properly...so no CNS carb for me. While taking apart my bike i did figure out the clip and needle stuff so now I can do that tuning on the stock carb when the time comes.

I have ordered a NGK Iridium plug and new plug wire. Is it easy to swap out the wires? do i open the CDI box at all?

I'm also ordering a SBP expansion chamber and was just wondering, which do i tune first, my carb or the exhaust?

I found opti-2 really close to home so ill be picking some up in the next week.

Just as a curiosity question... What would either an octane booster or racing fuel do? is it even worth it?

While I have the engine off and easy to deal with is there anywhere that i should add grease to? I have never added any before and would like to do a bit of maintenance while i have it apart.

Anyone know of a good place to purchase a twist throttle? the one i got with my kit was broken so i used a regular brake lever and would really like a twist throttle...they said they would send me a replacement but its been a month now...

Btw, found a local machine shop that with deal with my ports and fix em up. ^^

Thanks everyone.

silverbear · Apr 5, 2010

Just a few quick comments on what I feel competent answering. The plug wire just screws (twists) into the cdi box. Really simple. The old one just unscrews (to the left). Try it and you'll see how easy it is.
A mini bike twist throttle will work fine (look on ebay) or you might even post a wanted in the swap and shop part of the forum. No doubt someone has an extra kit throttle.
Sounds like things are coming along for you. Good you figured out the carb needle adjustment. Not hard either, but everything is daunting first time around. Careful with the spring shooting off on you or losing the little washer with the cutout. I lost mine the other day while putting a longer throttle cable on and made one from a washer, cutting out a little portion with the dremel tool cutoff wheel. If you do much more of this bike work at some point do yourself a favor and get a dremel mototool or clone of one. An inexpensive one is good if you're on a budget and used is ok, too. If you're going to use one a lot, then new and spiffy is even better. I have two, both old, basic and used. I don't know how I would do this work without one. i have not heard good things about an octane booster or special fuels. Good you found opti-2 locally. I have heard nothing but good things about the SBP expansion chamber. I'm sure you'll like it. I can't comment on the CNS carb or the intake manifold as mine are stock. Good luck to you.
SB

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Very new at this

Fizzbane

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silverbear

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bluenosegoat

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Bikeguy Joe

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Fizzbane

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Fizzbane

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silverbear

The Boy Who Never Grew Up