Popping and Backfiring
Posted August 28, 2000 - 02:49 AM
Current setup: Main 172, YZ needle at 4th clip, 48 pilot and fuel screw 1 3/4 out. This setup was run from 6000 to 13,000 feet.
However, I recently began to experience popping on deceleration. So I set the fuel screw to 1 1/2 out. This seemed to help.
Then on my last two rides (6000 to 8500 feet), I have been experiencing backfiring on deceleration. Last night I changed my main from 172 to 170. Am I going in the right direction here?
Pulled my plug and it appeared to be tan (if not leaning a smidge towards white). It was black around the bottom of the rings though.
Any thoughts on this?
Posted August 28, 2000 - 05:59 PM
Dougie if you check all this stuff and everything is OK then start richening the mixture at idle to just off idle by opening the fuel screw 1/4 turn at at time and see if it stops. If this does not satisfy you then get the DVP needle (#4 starting clip) it is ever so slightly richer on the straight section and start with the fuel screw at 1.0 and repeat the opening of the fuel screw until it stops.
Or if it is truly minor in nature live with it and press on and enjoy riding. Remember as fall and winter approach and the air temperature drops jetting changes may be required to richen things up ever so slighly.
Dougie if you were running race gas or a combo of race gas and pump gas and then switched to straight pump gas this also will lean out the jetting and require jettting adjustments.
Posted August 29, 2000 - 12:31 AM
Posted August 29, 2000 - 12:49 AM
Either by an airleak or most prob a poilet jet thats too small or fuel screw too lean.
**Ride it like you Stole it!**
Vist the Rubber Chicken Racing Online Shop
Discounts for ThumperTalk members.