tuning a freshly ported and matched polini 64 with 14 bing

anyone out there know a good range of jets to begin the tuning process for a polini kit that has been opened waaayyy up? i am a complete noob with carb tuning, but i realize the importance of keeping this thing cool and lubed at high rpms... any suggestions would be greatly appreciated.

Re: tuning a freshly ported and matched polini 64 with 14 bing

Normal range is 86 - 92 with a 15bing

My case was matched pretty aggressively and I was at a 92.

===

Make sure you have no leaks and that your timing is set right, and your mix is solid (Polini recommends a full synthetic 60:1 ratio).

Re: tuning a freshly ported and matched polini 64 with 14 bing

thanks man,

yea, she is tightened up, timed with a cdi to 1.75 btdc and running a homoet 6p pipe. ill order up a couple more sizes from treats...

Re: tuning a freshly ported and matched polini 64 with 14 bing

86 in 15 bing at sea level

Re: tuning a freshly ported and matched polini 64 with 14 bing

Overpriced Parts /

Where did you get your timing info?

1.75 mm Is that at the plug hole? That's like 20some degrees thats

so too high.

If its 17.5 degrees or mm at the flywheel that's still too high of timing for a polini.

16-16.5 degrees before before top dead center is what will Keep you from boom. Running a tiny carb on a ported polini is dumb.

Prolly 78-84 jet for a real 14mm bing with a 222 atomizer

Re: tuning a freshly ported and matched polini 64 with 14 bing

revisited the timing and took it down to 16 to be safe. thank you for the heads up.

the small bing is all i have at the moment. do you think it is incapable to the point of causing harm? or just not hitting the kit's potential?

Re: tuning a freshly ported and matched polini 64 with 14 bing

Overpriced Parts /

Tiny carb for break in maybe I don't know.

If a new kit I'd break in for 300 miles @ normal moped speeds.

Watch head temp gauge like a hawk especially with that hi rpm pipe and metal missing from porting. The biggest thing with a seized polini is the opened up from porting intake warpage. I break in my polinis before I port them cause the more metal on the intake the better.

Also with hi rpm running like you want to do a curve ignition is a must to keep down head temps.

At low 400 degrees head temps polini's are known to seize

Ya you got a miss matched set up.

Straight ign no curve, small carb with mid gears like 17x40 and a low rpm pipe like Estroil is a matched set up.

Yours is not

Re: tuning a freshly ported and matched polini 64 with 14 bing

I'm breaking in a 64 polini kit right no also. I hit 376 degrees today, that scares me that these polini kits seize at as low as 400. I already seized one kit prior to this but didn't have a temp gauge. I think I need to switch from 50:1 conventional to 60/64:1 amsoil saber to see if it helps out with my temps. I litterly have to baby the hell out of it to stay under 350.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account