new impellers and wear rings RPM mismatch

[romerodt1209]

just replaced my impellers and wears rings. everything was great expect at half and 3/4 throttle there is a 300 to 500 rpm difference any one having this issue?,

 

[rotaxrule1]

More than a couple hundred RPM difference is probably concerning. Is your ITC not working? Usually, you can see a "SYNC" light on your dash to indicate that it's engaged and keeping the engines in sync. Mine lights up shortly after I am underway. This is assuming you're talking about your 2010 challenger 210?

 

[jgrod@d]

I had a similar experience. I replaced the right engine wear ring and impeller on my 2009 Challenger se, and that (right) engine was turning less rpm's at full throttle than the left side (all low speeds seemed to match). The boat was just as fast, or just a hair faster than before any work was done so, in my mind, thought it was doing so because it was 'more efficient' than the older left wear ring. I have never seen a sync light, and the difference is around 500 rpm. I bought the boat used so theres a lot of unknowns. I'd like to see if anyone else has some imput on this.