rough run

[apndrvs]

i recently have cleaned all my carbs and replaced my plugs. i got the bike started today. it idles fine and when you give it gas it feels very strong with no hickups but while riding the bike at a constant rpm mainly between 2000 and 3000 it feels very sluggish and non responsive. i did do away with the stock exhaust and now have an open exhaust (not open heads). does this sound like a stock jet problem?

almost forgot it is a 79 xs11special.

[cywelchjr]

I've not heard of anybody getting these things to run well and smoothly in all ranges with open pipes. These bikes don't like not having at least some back pressure. Even with a cherry bomb glass pack (tried by former member Ivan), tuning was nigh on impossible because of the lack of back pressure.

[tinman905]

Have a looky here it may help you.
http://www.xs11.com/forum/showthread...=&threadid=382

[DGXSER]

As Cy mentioned, in the time I have been a member here, several folks have ran open pipes. All I can recall eventually put in some type of baffle or replaced with stock or similar exhaust.

If you just do not have exhaust with baffles, some folks have gone with supertraps inserts and had goof luck.

[apndrvs]

Tinman thanks for the info. I'm assuming you are suggesting that I re-jet my carbs. It may be me but I found the article a little confusing. I have a custom 4 into 1 exhaust (no baffle) I also have the 4 individual pod filters. All my carbs are stock. What size jets are u suggesting?

[apndrvs]

Thanks DG I may end up looking into some inserts. I just like the sound of the open pipes.

[DGXSER]

You would adjust up 2 jet steps for the 4-1 exhaust.

Up 3 jet steps for the pod filters (individual filters)

Total of 5, then subtract 1 = up 4 jet steps. Each jet "step" is 2.5 sizes, so up 10 for your bike.

Stock jetting in 79 was 137.5 mains IIRC, so you want to run about 147 main jets.

For your pilot jets....go up 1 step for every 3 main jet steps. 4/3 = 1.3333 or 1 step = 2.5 size. Stock pilot in 79 was 42.5 so you want 45 mains.

This is a starting point, not locked in stone will work. With you having no baffles, you may need bigger jetting.

You may like the sound of open pipes, but EVERYONE in your neighborhood will not. Trust me, BTDT got the nasty looks!!

[crazy steve]

With open pipes, even with a rejet you'll still have issues with low/midrange performance. If you don't mind the performance/drivability hit (and POed neighbors), have at it...

[petejw]

that low end problem is usually float level or idle circuit related,
but as the others have said, open pipes and pods can
exasberate(sp) the problem, having the early model carbs
with the vent tubes doesnt help either,
ur sig states uve rejetted ur carbs, what jets are you running
also what levels did u set the floats at?