V150TLRC surging...Please help!

[Jklowe]

I have a 04 Triton TR186 with the Yamaha V150TLRC. The whole set up has less than 50 hours on it from new purchase in 2004. I’ve noticed an up surge of RPM at full throttle. No more than a couple hundred rpm surge for a split second. My first thought was spark plugs, my thinking was I know the setup has less than 50 hours on it, so the plugs have probably never been changed. So, I changed all the plugs and took it back out on the water to test. Changing the plugs may have helped slightly, but the surge is still there. What else could be causing this issue? Any info would greatly be appreciated!

[Reata210]

Good chance it is fuel related. I would siphon tank dry and start with fresh fuel and Ring Free and a stabilizer. If there is a 10 micron between tank and bulb I would change that and the under cowl filter in clear bowl. Although unrelated to your issue, due to age not hours I would change out the impeller as well.

[Jklowe]

Thanks for the help! I’ll have to find a place to put 30 gallons of fuel

[Reata210]

Vehicle, equipment. How old is the fuel?

[Jklowe]

Just a few weeks, I’ll find somewhere to use it!

[Reata210]

With 50 hours on an 04, how long did it sit with old fuel? The VST could use a new screen as well as a cleaning. I would go through the entire fuel system. If bulb is original it is due as well. Good luck!

[Jklowe]

The guy I bought it from never left fuel in it. If he knew he wasn’t going to use it for weeks at a time he would siphon the gas out.

[Reata210]

Pri-g is a great fuel additive I run in every tank with ring-free. Helps keep fuel system very clean. I have used it 12 years with my 225 and 17 years witha 130 I owned. Many have luck with running Seafoam as well. One you change all filters and sure of the fuel condition get out and run it. Great chance you will work the issue right out.