Just pulled the plug and it is bright white. How can it possibly be running this lean when I didn't change anything on the carb. what should I do.

 

I think I narrowed it down to the mainjet. I checked the intake boot for cracks, adjusted the air screw all over and I still get a lean reading on the plug, and it won't wind up. Does this sound like a main jet problem to anyone else? I am still having a hard time believing that a simple endcap mod could effect the jetting so much though. I guess I'll have to wait until my jets come unless anyone else has any ideas. Thanks for the help so far[img]i/expressions/face-icon-small-smile.gif[/img]

 

Sounds like you are running way too lean. Yes a modded end cap can lean it out a few jet sizes. It has been awile since I ran the stock carb but I seem to remember that a 172.5 Mikuni main jet works at your elevation. Your stock jet should be a 165. You might buy a 167.5, 170, and a 172.5. Start with the largest one and if it sputters on the top end, back it down one size until it stops sputtering at top.

 

where In Michigan R/ U ? im in the thumb 3 miles off of lake huron.


this is my set up it I really like the performance 172.5 main, clip on middle notch, #45 pilot,
2-1/2 -2-3/4 out on the air screw, uni air filter and im running a 5 inch supertrapp disk on stock exhaust. air box lid on snorks off. your elevatin should be realy close to mine. after you get your new jets in and it still acts up I would look at the diaphram above the slide make sure its not got a pin hole or its not seated right. some times that can be a real b!tch to get seated in that cap. second the boot between the carb and the intake manifold is notorious for cracking you really gota be carfull not to over tighten it like I did $25 bones down the drain.

after reading the other post about air volicity comming in the air box I might put the snorks back on but shorten them.
hopw this helps [img]i/expressions/face-icon-small-smile.gif[/img]

 

Gentlemen,

I think he has found the problem, Check his NEW thread.





Bigger.

 

Thanks everyone. It was the needle on the clip. She's fixed now