I just converted my lift from a 150 CC to a 195cc.
My lift has 2 I- beams with the one down the middle. Has the two thick wooden beams that the boat sits on. The I beams are 145 inches from outside edge to outside edge.
1) in order to accommodate the new boat I had to raise these wooden beams by 1.5 inches. Pretty easy just removed and drilled new holes with 1.5 inch blocks sitting on the metal beams. I then set them to the width indicated on the boat trailer diagram. Placement of the middle I beam limited me a little from how far I could move the next set of bunks, but lucky that it was still far enough from the pier. Once the thick wooden support beams were set these were the reference point for all other supports.
2) I had two bunk supports inside of these beams from my 150 CC but very warped from spanning the 145 inches. I replaced the boards and set the width and height based off the height difference from the trailer diagram on bunk layout. Can't remember but if the outside said 7.5 high and inside said and inside said 4.5 that I just set them 3 inched lower that the outside beams.
3) Ordered adjustable bunk bolster brackets(etrailer 13 inch set) 4 each. Made two small 24inch bunks that attach only to the front I beam in the middle to mimic the v block on the trailer. I set these at so the v was at the correct angle and height difference from the outside beams. I made these 24 inches since the boat will never be exactly at same spot on a lift without a stop, but 24 inches should be enough to assure always correct support where the v block sits on the trailer.
4) Because the two full length bunk boards are 145 inches, the diagram has the support @ about 103 inches, I made a beam out of two 2x6's screwed together. I cut notches to hold the bunks in the right height, angle and location as the diagram. I this wooden beam sit on top of the I beam in the middle and is attached with joist hangers to the outside this wooden beams.
5) Last put the boat on the lift and made sure outside beams were equal distances on the bottom(after several attempts in the wind got it there). Then adjusted the inside next set of bunks slightly to assure contact with the bottom of the boat. This is also fun in a kayak in the wind. The small v-block bunks were pretty good just had to adjust one so ran perfect in line with the keel.
Just some notes, make sure to counter sink all bolts on bunk boards before carpeting so bolt heads will not contact the boat bottom. It was much easier when I stated the project and the water was frozen.
