Chinging sound at full throttle

[bakaracer]

you have to use a new plug when doing plug chops.if not your going to get a false reading.that plug is to hot for a bbk. run a cooler 8 plug.

[zajaco]

you have to use a new plug when doing plug chops.if not your going to get a false reading.that plug is to hot for a bbk. run a cooler 8 plug.

How long do you run the new plug in the engine before doing the chop? I've noticed that a mile run (down and back) isn't good enough to get good coloration on the plug. Perhaps that's because I am using a 6 plug?

On a side note I saw 56mph today with the new belt 8g rollers and the 140 main.

[bakaracer]

you have to use a new plug when doing plug chops.if not your going to get a false reading.that plug is to hot for a bbk. run a cooler 8 plug.

How long do you run the new plug in the engine before doing the chop? I've noticed that a mile run (down and back) isn't good enough to get good coloration on the plug. Perhaps that's because I am using a 6 plug?

On a side note I saw 56mph today with the new belt 8g rollers and the 140 main.

use a old plug to warm the engine up and then put a new plug in. a 4-5 second wot is good enough for a plug read. yeah if the plug is to hot the porcelain will clean itself off to quick. so a plug chop is warm the bike up with a old plug.put a new plug in. get up to speed and hold wot for 4-5 seconds.use the kill switch to shut the engine off while holding it wot and come to a stop as quick as you can so you don't get to much extra air and fuel to screw your plug read up. use a number 8 plug. that should be just right for your setup.

[zajaco]

Here is the most recent attempt with a BR8HSA plug and a 140 main. Im not sure if I am not stopping fast enough or what but im not getting much coloration out of these either.

[bakaracer]

bump that pilot to a 58 and run the 142.try that and see if that ground strap gets darker.it looks gray.look for a smoke ring at the base of the porcelain also.

[zajaco]

I defiantly got better coloration with the 142 main and 58 idle. I didn't have to adjust the a/f screw with the new idle size... The motor reved up and down smoothly with the A/F about 1.75 turns out.

The grounding strap has good color but the porcelain is still white. According to my chop chart here that still puts me a bit lean. I think I need to go up one more jet. What do you guys think?

[bakaracer]

OK those plug charts you see are for 4 stroke plug reads. the 2 stroke plug chop reads are the base of the porcelain and the ground strap. the mid to top of the porcelain will still be white with a new plug. your looking for a smoke ring at the base of the porcelain and the coloration at the ground strap. your ground strap looks good. what is your compression at right now? do a cold and warm engine compression test.whats your oil to gas mixture?

[zajaco]

Ah, thanks for the heads up. Yes, there is a smoke ring near the base of the porcelain.

Cold compression: 135
Warm compression: 131-132
Fuel to oil: 32:1