The power of my engine is weak!!

StrontiumEthics · #1 04-06-2009, 06:43 AM

For some reason the power of my engine is weak. Im not to sure of the cc's because I got it from Revolutioncycles.us and it was kind of a replacement. Supposingly it was a 80cc (well 69.9cc) or something around that range. I also have a SBP Jackshaft kit connected as well. What I realize is that the engine is not using the gears as I hoped it will. The power is weak. I dont really have a speedometer, but I can guess that my max is about 30-34 mph. It is suppost to be way more. In addition the take off and acceleration is pretty bad to, it takes to long to get to my top speed. Basically, I am comparing the engine I have now to a Dax 80cc. In the dax things felt alot better and smoother, this engine is kinda slow I dont really like the way it feels. Is there any things you guys recommend that I check? I was thinking to drill a hole on the exhaust according to some of the people on the forum. This might work because when I ran the engine without the exhaust the takeoff was beautiful. But im not to sure what I should do. Any recommendations/ things I should check? I prefer not to actually do any engine work (taking off heads).

**Ilikeabikea** · #2 04-06-2009, 07:44 AM

You might check your plug for fouling. Make sure it's clean and gapped properly. What is your oil/gas mix ratio? Maybe a new plug wire. Do you have a fuel filter between the tank and the carb? Just a few basic things to try....................

**Bikeguy Joe** · #3 04-06-2009, 08:44 AM

Good advice.

When you check your plug, the color is very important, should be tan/brown/just black.
24:1 -32:1 mixture with fresh gas.
C clip on the second notch from the top.

Finally, just because you have gears, does not mean you will gain miraculous top speeds. Top speed is determined by total horsepower output.

StrontiumEthics · #4 04-06-2009, 02:15 PM

What should the gap be on my spark plug. I am currently running a NGK B6HS, I dont think its plug fouling because its a brand new sparkplug, and I put about 100 miles or less on the engine. I had it since last year but since i live in new york the snow caused me to take it apart until now. What spark plug wire should I get? Any recommendations? I was thinking putting a hole in my exhaust to let out some back pressure... when I ran it without a muffler for like 45 secs It was REALLY NICE. So maybe that might make a difference...

StrontiumEthics · #5 04-06-2009, 02:16 PM

No I dont have a fuel filter. and my ratio is 1: 16

Goat Herder · #6 04-06-2009, 02:30 PM

Here is one of my muffler tricks, a little ugly but I like it.http://motorbicycling.com/f15/sbp-ja...ules-6862.html

StrontiumEthics · #7 04-06-2009, 02:33 PM

Another thing, when I just rev the engine (Clutch Engaged) and I give it full throttle it looses RPM's at full throttle, like it goes up and down a little, it DOESN'T just go VERRUMMMMMMMMMM like its spost to. Its not losing RPM's to a point where it shuts off or something like that, but it kinda jumps a little, it doesn't stay stagnant. What do you think is the problem?

Goat Herder · #8 04-06-2009, 03:36 PM

I had a cdi breaking down one time It did something like this. Ride for awhile see if the cdi feels warm it should not.

Ghost0 · #9 04-06-2009, 04:04 PM

Sounds like crud in the carb to me. I would take it apart and clean the float bowl, jet and adjust the float while you are there. Definitely get a good fuel filter.

**Bikeguy Joe** · #10 04-06-2009, 04:06 PM

Gap the plug around .020-.025"
Go to 24:1 asap.
Your engine could be sagging when you rev it like that for several reasons....fuel starvation, carb setting, float adjustment, ect.