TOPIC:

Ok guys. 3 years ago my timing chain broke and did some damage. I picked up an 81 motor and put it in. Same setup as before. Open header and pod filters. Used my carbs that I had put the dynojet kit in. I’ve spent the last couple weeks changing clip positions and I needed bigger pilot jets. It’s running better than ever but my fuel mileage is gone. I rode to work yesterday and today which is around 50 miles total and I’m gonna have to get fuel after work. That’s about 25 mpg. No fuel is leaking that I can find. Doesn’t smell like fuel when running. No smoke out exhaust. I’m at a loss on what has happened? Any ideas would be appreciated. Does raising the needle clip affect that? It’s all highway between 65-70 mph. 
thanks. 

Raising the needle or raising the needle clip?
Raising the needle is opening the needle jet richening the mixture at higher revs - reducing the mpg. 
Raising the needle clip lowers the needle leaning the mixture at higher revs - increasing the the mpg assuming you've not leaned it off so much that you needle more throttle to get the same  power required to pull the higher gears. 
 

What grade of gasoline are you using? 

When I bought a totally stock low mile KZP I was stunned to find it only got 30 mpg. And they have a four gallon tank.
I rejetted and it now gets 45+ mpg.

I keep getting this

ErrorKunena Internal Error: Please enable Kunena Debug Mode and report problem in the  www.kunena.org  forum.

Lowered the clip a couple notches so raising the needle. I can’t believe that would double my fuel consumption. 
91-93 octane if I can find it. 

Beaner242 wrote:

Lowered the clip a couple notches so raising the needle. I can’t believe that would double my fuel consumption. 
91-93 octane if I can find it. 
 

What carburetors on your engine?

I don't know why, but my spark plugs get a fluffy black carbon buildup on the base ring when I use anything besides Regular 87 E10 pump gasoline.

BS 36 I believe. Whatever stock is other other than the dynojet kit I put in them

If able, please post a picture of the spark plugs for member evaluation.

Beaner242 wrote:

Lowered the clip a couple notches so raising the needle. I can’t believe that would double my fuel consumption. 

 

Lifting the needle will increase low and mid range fuel consumption which is where you are spending most time at cruising.
You likely need to drop the needle, put the stock pilot back and richen up the idle mix on the mixture screw instead.

I am going to lower it when I get home and see where it goes

Update if anyone is interested. Returned the needle clip in the second from top position. Installed 45 pilot jets. Fuel screws are 3 turns out. Just went for ride to test it. Back up to 45 mpg. So much better.