Yamaha 130 Problem

drmatt18

Recruit
Joined
Dec 27, 2003
Messages
1
I've got a 96 130 and the trouble began when it started idling rough. It still ran like a raped ape on the top end and I was getting all the normal RPM's outta it. It was using the normal amount of fuel and oil. Since I had a chance I brought it up to Yankeetown with me over Christmas break and was going to let my buddy work on it. My friend is an awesome mechanic and has several years of experience at a local Yamaha shop. Basically the engine is running rich and getting way to much gas. The plugs are wet with gas when you pull them and a sheen of gas is visible on the ground when you start it on the hose. He immediately thinks the fuel pump is bad. If the fuel pump gasket is bad extra fuel gets dumped into the #4 cylinder. He pulls it and puts a new fuel pump on and it still does the same thing. Next night he comes over and rebuilds the carbs. Still the same problem. The engine runs a little better after you totally lean it out with adjustment screws but that's just putting a band aid on the problem. All the ignition components checked out and all cylinders are getting spark. Anyone have any idea's what to do next?
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Yamaha 130 Problem

hello<br /> now ya need to test the stator output voltage with the motor running. also test the plug firing KV. I ran into a 250 last year that had the same symptoms. the complaint was of wet fouling plugs. I would test all the ign components . on the 250 as the engine warmed up the stator charge coil voltage would decrease tpo about 50 volts. enough to try to fire but after a bit it would wet foul the plugs and quit.<br /> good luck and keep posting.
 
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