I have a 1978 8 HP SVE motor in my Hunter 1978 H-27. This last week I've lost power in forward. The motor seems to be putting out the right number of revs and all seems in order in reverse. I think that the transission is slipping. I had the problem at the start of the season. I changed the transmission oil and it cleared up. Now the problem is back. I've recently replaced a frozen shift cable, I thought it might be the cable adjustment so I disconnected the cable and shifted by hand. The problems is still there. When I shift into reverse I hear that normal low whine of power to the shaft that I've always heard. I used to hear it forward but not any more, the trans. seems to be slipping. When I shift into reverse I feel it clunk into gear. I used to feel it when I shifted into forward but I don't feel it now. I do get some revs to the shaft in forward, but there is slippage. Can you recommend some diagnostics or give me a clue of what might be wrong ? Do you do a clutch job on these motors ? Internal shift linkage ? And lastly if you do do a trans job, do you usually do it in the boat or pull the motor? I'd really appreciate your help. Thanks