1997 speedster brought it home put it in the lake and now the starboard motor seems to surge when running. On the hose in the yard it seems fine but on the lake it surges and is hard to keep even and going straight? The tach does not seem to read even when throttles are in the same position. All this seems to be above 4000 rpm but not sure. Any help would be appreciated as I am new to seadoo's