engine leans out mid throttle

[BSA]

I haven't had a chance to muck about with it yet, but I will do yet. I will clean out the exhaust as I am using a lot of standard dino oil (16-1 mixture), and I'm running a rich mixture. That makes a combination for a lot of soot and gunk to accumulate in the exhaust.

BSA

 

[sparky]

I figured there'd be lotsa carbon buildup in my small exhaust since I was running 20:1 of dino... but I doubt I've had it long enough to clog it up.

If I did want to clean out my exhaust, how would I do it? Put it in some boiling water and then blow it out with an air compressor??

 

[sparky]

Could an exhaust leak be causing this mid-throttle problem?

I'm thinking it's either all the leaks I've got or the plug wire for me.

 

[Large Filipino]

... I'll just get an expensive 8mm hi-performance one from the auto parts store.

Sparky,check these posts out before you do that:
http://www.motoredbikes.com/showpost.php?p=81510&postcount=17
http://www.motoredbikes.com/showpost.php?p=86285&postcount=46

That could be your only problem here. Plug wires make a WORLD of difference.

 

[sparky]

Large, I replied in that thread asking what you asked for at the NAPA place. They said they don't do single wires.

See here: http://www.motoredbikes.com/showthread.php?t=3981&page=8

I went to the small engine repair guy & he said I've already got solid core, but I dunno what kinda metal it is. The terminal seems beat up, but the wire seems pretty thick. Also, I can't replace the CDI (easily), so my only option is to splice in a new plug wire?? Would that still improve it as much as you guys are seeing? Is it just the terminal? That's what it seems like to me.

 

[gtowncronie]

Similar but different

Hey- i just got my new motor from Spookytooth and it rips hard, untill i throught a bit mor gas/oil that i may have not calculated right (i'm pretty sure i got danm close to the reccomended 20:1... anyway this morning was a bit chilly and when i fired it up it took a while to get idling smooth, and after about 5 min i tryed to go through the power band and about 1/2 throttle it started spuddering and then sa couple backfires out the carb! so i backed off and took it real easy to work and at lunch i went to the motorcycle shop and got another oz of oil and that owrked a little better, i was scared of being to lean (second guessing my mixing ability) when i move the choke up it runs worse but doesnt die, i play with the idle screw and it doesnt seem to make a difference at all, and im 95% sure im 20-25:1 mixture, i dont have many miles on it and like i said before it was rippin yesterday, i just dont know what it is!!! please help
-frame mount ST 80cc on a GT Kustom Kruiser at sea level and about 50°F