my engine will run for a while before the water pump will start to push water out, then stop after a few seconds(4-5) then start again then stop...is this normal or is my impeller broken?
Yes thats how i learn on my 25 johonson if you have any trouble come back here these guys are great they help me do my90 hp mercury ingition system step by step .
You must have Adobe Acrobat reader installed to use this manual. If you scroll down to the lower part of the opening page, you will see the various engine components in red. Click on the one you want and when the first page opens, click on the "Save As" icon at the top LH corner of the page and you can save it to your computer.
Page 6A-12 (Gear Housing) will get you started removing the LU from the engine, then once it is off, to page 6A-16 for the waterpump.