carb adjustment?

Dougan · #1 08-26-2010, 11:35 AM

I just replaced m yspark plug and changed from 25:1 and 32:1. My bike rides like it's choked a little bit and won't get above 22 or so (maxes around 30). I took the intake filter off and it rides beautifully without the filter. Cleaned it, put it back on, rides like it's choked.

I know little about carbs. But it sounds like I need to open it up and adjust the needle or float or whatever that is. Does anybody have a tutorial for something like this? Sounds common and I couldn't find one.

Unless you think there's a different problem.

Venice Motor Bikes · #2 08-26-2010, 12:49 PM

Move the C clip on the needle up a notch or two, & post back how that worked.

Dougan · #3 08-26-2010, 01:56 PM

Does anybody have a picture of this?

GearNut · #4 08-26-2010, 04:27 PM

http://motorbicycling.com/f4/motoriz...stall-195.html

ferball · #5 08-26-2010, 05:23 PM

Don't be afraid of taking the carb apart, that stock carb is one of the simplest carbs I a have ever torn into, the only "tricky" bit is the pin for the float valve, it wants to fall out, but that is the worst of it, tear it open it is kinda fun...

Dougan · #6 08-26-2010, 08:58 PM

Okay, thanks for the tips.

I took it apart. Was set to #2 from top. I moved it to #1. I'm fairly certain that this helped a little-- not sure if I am just making it up, or if it actually helped. But either way, it didn't help enough. The bike is acting like it's a little choked, and won't make it to its normal max RPMs with the air filter on.

I tried moving it to #3 from the top just to see, and this seemed to make it worse just a little.

Checked for air leaks, none. Tried messing with the cable at the top of the carb, no effect.

Spark plug is L86J, 32:1 amsoil dominator synthetic. The carb I've got is the one with the red intake. Ive seen a efw pictures of it around here.

Weird thing is, if I am at even the slightest downhill grade, it seems to help and I'm able to get up to about my normal max speed. It seems like it runs just a little better after about 1 mile of riding, when it's fully warmed up.

Any other tips?

GearNut · #7 08-27-2010, 03:26 AM

How many miles are on the engine?
What is the float height set at? Spec is 21mm from gasket surface to top of float (actually the bottom of the float as this is measured with the carb up-side-down.

Dougan · #8 08-27-2010, 09:05 AM

The engine has about five gallons of gas run through it. I don't keep track of miles. But I'd have to guess 500-750 miles.

I don't know about the float. To be honest, I've never rebuilt a carburetor and don't know how to identify it. I thought that the needle and the float were kind of the same thing. Could you give me some guidance toward how to figure out the answer to your question?

Thanks!

NunyaBidness · #9 08-27-2010, 10:30 AM

That info should be in the post http://motorbicycling.com/f4/motoriz....html#post1184 linked to earlier in this thread.

and it is, check the pic in the third post in that thread.

Dougan · #10 08-27-2010, 11:29 AM

Quote:

Originally Posted by NunyaBidness

That info should be in the post http://motorbicycling.com/f4/motoriz....html#post1184 linked to earlier in this thread.

and it is, check the pic in the third post in that thread.

Appreciated, but got that taken care of already.