1998 gas Yamaha runs 20 seconds and dies

[Roger Parsons]

Have replaced several electrical parts but not the ignitor, any ideas, and how big of a deal is that to change?

[1arunem]

Have you verified no spark under no start condition? Sure it isn't fuel related?

I've had TCI's do something similar (cut out after getting hot) and also had fuel starvation problems exhibit similar symptoms.

[Yzshooter]

I agree that you should verify if it's a lack of spark or fuel. I just discovered that my G16 has a bad fuel pump. It's leaking gas into the pulse line and stopping the pulse. It will run the carb out of gas then die.(about 20 sec) I can blow the gas out of the line, spin it over a few seconds and it cranks and runs great until the next time it sits a few hours and the cycle starts again. I haven't noticed any signs of fuel in the oil but I know at least a small amount is getting in there. For me it's fuel pump time. Just thought I'd mention this since I haven't seen it anywhere else here and figure I can't be the only one who has experienced this.
Definitely determine if it's spark or fuel and go from there..

Good luck, Al

[Roger Parsons]

I am fairly sure it's spark related pulled plug and no fire. Changed fuel pump and filter last year with same symptoms. Ran fine until recently, and now it's intermittent and there is gas in the filter and plug is wet when it won't run. yesterday morning it seemed to run fine.

[Dave in VA]

Originally Posted by Roger Parsons

I am fairly sure it's spark related pulled plug and no fire. Changed fuel pump and filter last year with same symptoms. Ran fine until recently, and now it's intermittent and there is gas in the filter and plug is wet when it won't run. yesterday morning it seemed to run fine.

JN6-85640-00-00 TCI (coil) part #. Buy the Yamaha part, not aftermarket.

[Roger Parsons]

Got it thanks, wondering how difficult it is to change.

[1arunem]

Not too difficult. Have to get the side cover off.

I did have to raise the engine a bit to get one of the cover bolts off.

Also be sure to gap the TCI when reinstalling.

[Dave in VA]

The bolt on the bottom of the cover is a b itch to get out. I leave it out...

[cgtech]

Disconnect the plug at the front/bottom of engine (black & blue wires). With that plug disconnected, it will be able to have spark all the time. If it still fails, bad tci. If it keeps running forever & ever & ever, you have a good coil & badly need to adjust your carb/throttle cables. That second part is a "not funny joke". I had a cart that just kept running until I used my shoe sole to slow it down till it died. (Disconnecting the battery wouldnt work, tci makes spark without a battery).

[1arunem]

Originally Posted by cgtech

Disconnect the plug at the front/bottom of engine (black & blue wires). With that plug disconnected, it will be able to have spark all the time. If it still fails, bad tci. If it keeps running forever & ever & ever, you have a good coil & badly need to adjust your carb/throttle cables. That second part is a "not funny joke". I had a cart that just kept running until I used my shoe sole to slow it down till it died. (Disconnecting the battery wouldnt work, tci makes spark without a battery).

I have had to do the same but pulled spark plug boot.