View Full Version : 1985 yamaha 90hp not full power

04-30-2004, 03:28 PM
help my 1985 90hp yamaha starts good runs good but will only get to about 1ooo rpm will not plane out and sometimes won't shut off could this be my powerpack???? help.

04-30-2004, 09:40 PM
Could be absolutely anything. First start with a compression test followed by a spark test. Post results and we can then help you further.

05-14-2004, 05:42 PM
" I've got an 86 Yamaha 150 that has been great - but now has exhibited similar stuff. Compression is good, plugs are new, starts great, throw the throttle down and it fires and begins to climb, but then boggs down and won't jump on plane, (same prop) ... Once on plane runs good to 4500 rpm and refuses to go to full speed (which was always 5300rpm)...prop is a 21Turbo which had a recent repair, also recent repair was removing some water from fuel tank, cleaning all carbs, and new gasket on fuel filter ...... "

05-14-2004, 08:16 PM
check your plugs and see if you got spark take out plugs hold to ground could be your CDI unit i think thats what wrong with my 90h