MOTOR SOUNDS TELLS NEED  By  alleyoop (Read 4,808 times)

Different sounds a motor makes tells you what it needs, so listen for any sounds the motor makes.

1. Popping while accelerating is a RICH condition.
2. Popping while de-celerating is a LEAN condition.
3. Burp Sounds accelerating is a LEAN condition
4. Backfires are a Lean condition.

Possible causes for above and fixes:
1. Here the problem is it is running OVERLEY rich.
a. Enricher is still feeding extra fuel
b. Fuel is being sucked in through the Petcock Vacuum hose
c. The Fuel Ratio Mixture is to rich
d. If you changed the main jet it is to big..

2. Here couple things:
a. You can richen up the Fuel Ratio Mixture
b. Idling to low Bring up the idle a little

3. You can richen up the Fuel Ratio Mixture

4. Usually caused by it Leaking where the Pipe Connects to the motor. Bad air leaks cause the backfiring many think it is because it is to RICH but it is the OPPOSITE sucking in air causing very Lean condition and this can damage your exhaust valve.


If it just BOGS on you or starts dropping rpms or bucks but makes no distinguishing sounds then the good old Trick of the Trade will tell you what the motor needs:

TRICK OF THE TRADE:
Lets find out which situation(LEAN OR RICH) is causing the problem.
Run the sucker like you do when it STARTS TO ACT UP Back off the THROTTLE about 1/4 OF AN INCH and HOLD IT THERE:
A. If the scoot Speeds up it is running LEAN.
B. If the scoot Sputters or whatever BUT settles down it is running RICH.

This way you will know what it needs(more or less juice).