QMy engine works but we have little propulsion either forward or backward can anyone advise cocopop
It would help if you said what type of boat, what waters you are on and what gearbox you have so I can narrow the possibilities down. If this is on a canal I would suggest that you check the propeller has not wrapped itself up in something. Narrowboats normally have a weed hatch that gives access to the propeller. If you have a hydraulic gearbox but NOT a Lister one then make sure it has sufficient oil in it. Check the prop shaft has not pulled out of its coupling behind the gearbox. You indicate that you have some sort of drive in ahead AND astern so that points to a fouled prop in the first instance. Any gearbox fault is likely give you one good gear unless it’s low oil in a hydraulic box. There is usually something called a drive plate between the engine flywheel and gearbox. When (not if) it fails you tend to get no drive in any gear plus a horrible clattering noise for a while before it totally fails. If it seems to be stuck in just one gear it could be a gear cable fault but not if you still have a little ahead, astern and a neutral. Find the lever on the gearbox that the cable is attached to, operate the control lever and make sure the lever on the box goes fully to the ahead, astern and returns to neutral.