Loss of power

G

gunslingerburrito

New Member
Ok, now I'm sure this is a question that has been asked MANY times, and I've been doing my research, but I wanted some more opinions.

I have a 58cc 2 stroke, and it's around 120 miles now. I'm running it at a 24:1 fuel mix. It has a lot of power and gets up to 26-28 without hesitation after start up.

But, after around 5 minutes of running, it begins to lose power, and it seems like I have to push it to get it above 20.

What could be the culprit?
 
Im sure there will be other opinions but at 120 miles maybe its time for a new plug and a 32:1 to 40:1 oil mix.
 
Sounds like maybe your plug is too hot. Stock plug and direct replacements typically have a "5" in heat range. From my experience, that's too hot, even in cold weather climates. You might want to try a "6" or "7", preferably an AGK, like a B6HS or B7HS.
 
When it acts up next time, try turning on the chock alittle. If it runs better then you have an air leak.
 
One time I can remember one of my china two smokes doing this it was the cdi acting up after it ran for a while. Darn thing ran pretty good but after a while would loose power.
 
Goat Herder said:
One time I can remember one of my china two smokes doing this it was the cdi acting up after it ran for a while. Darn thing ran pretty good but after a while would loose power.
Click to expand...

May be this. If you check everything else as good, replacing the CDI occasionally fixes this loss of power problem.
 
Just an update, I replaced the spark plug with a b6hs and the plug wire/boot with one from SBP. It helped some with the power loss.

The main problem was that I had it running way too lean, which I believe was overheating the motor. I dropped the c-clip down a notch, switched to a 32:1 mix, and the power has not dropped since.

I also realized that I am using a 44 tooth sprocket, and I weigh 195 lbs. So my cruising speed is around 23-26 mph. It seems like the motor still needs to rev a little high to get to that speed, but maybe that's just normal for the engine size and sprocket I am using?

I did want to put another question out there. I have noticed this since the day I brought the bike above 20 mph, but I am hearing a thumping/knocking noise in time with the engine. I don't believe it is hitting the plug, the gap has not been shortened any. It seems to happen only when I have a load on the motor, not when I rev while idling.

I have not taken off the head to inspect it yet, but I routinely ensure that it is properly torqued down.

Any thoughts?
 
My gears (clutch-side) aren't perfect to say the least and they have some slack. I suppose that may cause some banging.
 
If i remember correctly you have the 58cc phantom motor? if im right , i also had that wierd same knocking noise. If i remember right, it kinda sounds like a low octane knock/ping. I think i got rid of most of that noise by using premium and a 40:1 mix with a good oil. The mottor still ran great until i srewed it up, my problem was my iccesant need to tiker with it and take it apart led me to strip out the head bolts in the case .
 
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