2003 Utopia 205 RPM issue

[Keithm1869]

1st time out this year. Only getting about 4800 rpm’s @ about 31 mph. What should I look at 1st? Utopia 205 200 optimax

 

[Tim75]

Visual confirm throttle plate opens 100%.

Check spark plugs. Are you getting spark on all 6? Use only OEM recommended brand and grade. While the plugs are out, do a compression test. On the trailer, at WOT.

Ignition timing.

How old is your gas? It it E10? Maybe E15? Any chance it has water in it? Any alky-gas can absorb water better than pure gas.