TaoTao ATM50-A1 has a lot more power when it's cooler outsid By nivanov (Read 413 times)

[nivanov]

Hi everyone,
In the last few days, I noticed that my scooter has a lot more pickup when it's around 70F as compared to 85F. When it's 80F+, I top out around 40 mph on the speedometer (around 35mph GPS verified). However, when it's around 70F, it reaches 50mph on the speedometer (over 40mph GPS). Acceleration is also noticeably better. I understand that engines heat up, so having cooler air around it makes a difference, but we're only talking about 15 degrees difference.

I was wondering what's the reason behind such drastic performance difference and what I could try to have that performance in a wider range of weathers? I use Shell Rotella T 15W-40, I have a performance CDI (Newmotoz Gy6 CDI from Amazon), and I've unsealed the stock carb since it was running too lean.

[kagetenshi]

I am just guessing here, but the temp affecting performance that much is probably due to a scooter's small engine size. Every little thing affects these smaller engines in a major way.

[Alleyoop]

Motors like cool air they make more power when the air is cool it is due to the density of the air.

So you will find ALL MOTORS love cool air. Remember in the HOT weather a motor needs less fuel so what do you do, you LEAN out the mixture and in the COOL a motor needs more fuel so what do you do you RICHEN the mixture. So think about it IF your carb is set for hot weather the mixture leaned out a little WHAT does that do when the sun goes down when it is cooler now your running a little on the LEAN SIDE making more power. On the other side of the coin If the carb is set for COOL weather lots more fuel then it WARMS up you will have a sluggish motor loss of power.

So you need to find the middle ground between the two and that is the best your going to get from the mixture when temps flucuate enough to effect performance.
Alleyoop

[nivanov]

That's a great explanation, thanks! I think I need to lean out the carb just a little bit - I'll give that a shot.

[cyborg]

not only that the fuel is cold too so it's more dense cylinder tighter on the piston,,,whole bunches of factors working in positive territory when cool