2016 RXPX 300 Won’t go above 35 mph


New Member
Hi all,

I’m new here but have owned for a while. Bought a used 2016 RXPX 300 that only had 16 hours on it late last summer. Seemed to run great the couple of times I had it out before it got cold here in Utah. Took it out for the first time this year a few weeks back and it is running sluggish. Starts and idles just fine, doesn’t seem to run rough but it won’t go over about 35 mph and doesn’t really rev past 4000. After running a tank of gas through it the issue went away and I thought it was over. Took it out again (full fresh tank of gas) after having replaced both fuel filters and it’s still running sluggish and won’t go over 35mph again. I’ve added a couple cans of sea foam along the way and some octane boosters. I have a Candoo scanner and hooked it up and it’s not throwing any codes of any kind.

I’m kind of at a loss. It now has about 30 hours on it. Not sure if it’s gas, maybe it’s fouled spark plugs or a dirty fuel line??

Any help would be much appreciated!
I am having the same problem since Sunday just install new sparks but has not try it yet did you solve your problem?
Yes, all it was was a bad spark plug. Replaced all three and it’s back to normal. If you’re having a similar problem and it’s not the plugs I’d try moving the coils to different cylinders to see if it’s a bad coil.