Lost pull and speed up hills

[Jaycee604]

So i recently took off the nt carb and installed pz20s on both of my bikes. I got them to have great acceleration and top speed but now one of them isnt that great up hills anymore. Could the temp change the last few months do anything? Both have the same setup. Also i am 200 pounds and my bikes will go around 55kmh on flat ground. Let me know what you guys think.

66cc case matched cylinder and polished exhaust port
Mz65 clone pipe
Window piston with g2 reed valve
Pz20 carb with a 65 jet
44 tooth
High comp head
Squish gap 0.30mm
Plug gap 0.30mm
Ngk br6hs with aftermarket cdi
New gaskets and seals
Skf bearings
40:1 mix with 91 octane and lucas oil

 

[Greg58]

It does sound like the weather change has affected the engine, what does the spark plug look like? The best way to diagnose a running problem is checking the color of the porcelain part of the plug, you want a light to medium brown color, black is too rich, light gray is lean. Also you can try tightening or widening the plug gap a little and see if that changes anything.

 

[Greg58]

I run my plug gap at .26-.28 thousands, sorry I’m not good with metric measurements.

 

[Sidewinder Jerry]

Head winds vs tail winds can also make a big difference. Yesterday, the road I was on has several rolling hills all with about the same grade. While riding down a hill with a tail wind I was doing close to 40 mph. On the way back going down hill with a strong head wind I could only do 28 mph.

If wind wasn't the factor and since you're a single engine ratio drive you may want to consider switching between a 9t and a 10t engine sprockets for weather change ups.

 

[Jaycee604]

It does sound like the weather change has affected the engine, what does the spark plug look like? The best way to diagnose a running problem is checking the color of the porcelain part of the plug, you want a light to medium brown color, black is too rich, light gray is lean. Also you can try tightening or widening the plug gap a little and see if that changes anything.

the color of the plug is pretty good,a dry light brown all over. I have tried messing with the plug gap and didnt really feel much of a change.

 

[wrench]

I run my plug gap at .26-.28 thousands

LOL Damn that's huge. maybe you should try .026" -.028" thousands

 

[Jaycee604]

LOL Damn that's huge. maybe you should try .026" -.028" thousands

 

[Tyler6357]

"New gaskets and seals"

Are you sure you got them in good, those rubber case seals have been known to get jarred out of place causing a leak. A loss of power like you describe sounds like an air leak somewhere.

 

[Greg58]

LOL Damn that's huge. maybe you should try .026" -.028" thousands

How old I are!

 

[Greg58]

Wrench I think as long as you add the "thousands" everyone knows what you are talking about.

 

[Jaycee604]

"New gaskets and seals"

Are you sure you got them in good, those rubber case seals have been known to get jarred out of place causing a leak. A loss of power like you describe sounds like an air leak somewhere.

The rubber seals are in perfect. No oil leaks. I have tested them for leaks too. Also my reed valve has epoxy around the outside where it would leak if the gaskets fail.

 

[wrench]

Wrench I think as long as you add the "thousands" everyone knows what you are talking about.

But it's funny, if ya can read the decimal point
because .26" is a thousands # and .026" is a thousands #

But since ya said it's for a spark plug I'm sure everyone knew what ya ment

.250" = 1/4" spark plug gap is huge LOL