Frank Acampora
Supreme Mariner
- Joined
- Jan 19, 2007
- Messages
- 12,004
BAXTR: Everytime I try to reply to your pm, I get cut out. So I will answer here. Besides, I think some of the forum members will be interested.
When I told the fellow that he should be unhappy if he got less than 45 mph, my reasoning was this: It was an 18 foot Bayliner Cuddy so the length and width should probably be similar to the 18 bass boat that I rebuilt. Given the extra weight of the cuddy, I would expect less mph but the high performance reeds would make up some of the loss--so I guestimated 45.
Your boat being a 19 footer is longer, wider, and maybe a little heavier, and probably has more wetted surface area. 42 gps aint too shabby. However, I suspect that if you are not using a stainless prop and you change to one in the same pitch you are using, you should pick up about 2-400 rpm and 2 mph.
Now, Here's what I did to the 125 I rebuilt: one piston was melted and one looked dry so may have beem worn. When I took the block to the shop, they miked it and all four cylinders were out of specs. So, I told the owner that he needed 4 pistons. Shop said they needed to overbore .030 to clean up the melted piston cylinder. I ordered Wiseco pistons and nasty little surprise: I had to wait three weeks until pistons were manufactured. So I had some time on my hands. Since the owner had to wait, and I had nothing to do, my hands got itchy and I went in and did a little mild port work in the bypass side. Nothing major, just trumpet shaped the ports with a Dremel to ease gas flow and give the engine an "edge". Replaced 4 pistons, head gasket, exhaust chest gaskets, fuel pump diaphragm, water pump impeller, and replaced all exhaust cover screws with stainless. Cleaned carbs and set floats a little high on the premise that it is better to run a little rich than a little lean. Timing link looked wrong so I re-set it to where I thought it should be. Owner said speedo never worked so He did not know what speed he had before problem, but engine ran at 5,000 rpm. I blew out the pitot tube.
Went to the river with the owner. Engine fired first time and although it ran a little rough, it settled down when it cleared the assembly oil. YES! It was going to be a good day! This one was behaving itself.
Took the boat to the shallows where there was no traffic and checked timing Dead on 30 deg at WOT. That's dumb luck. ran slowly for a while to build up some oil then checked speed with owners original prop on short high speed run to 40 mph at 6,000 rpm. Changed prop to my 19 pitch stainless. One more high speed run to 47 mph at 5,400 rpm. Never bothered to check any other props--that's the one. Ran the rest of the tank out at about 3,000 rpm. Engine was just humming.
When I told the fellow that he should be unhappy if he got less than 45 mph, my reasoning was this: It was an 18 foot Bayliner Cuddy so the length and width should probably be similar to the 18 bass boat that I rebuilt. Given the extra weight of the cuddy, I would expect less mph but the high performance reeds would make up some of the loss--so I guestimated 45.
Your boat being a 19 footer is longer, wider, and maybe a little heavier, and probably has more wetted surface area. 42 gps aint too shabby. However, I suspect that if you are not using a stainless prop and you change to one in the same pitch you are using, you should pick up about 2-400 rpm and 2 mph.
Now, Here's what I did to the 125 I rebuilt: one piston was melted and one looked dry so may have beem worn. When I took the block to the shop, they miked it and all four cylinders were out of specs. So, I told the owner that he needed 4 pistons. Shop said they needed to overbore .030 to clean up the melted piston cylinder. I ordered Wiseco pistons and nasty little surprise: I had to wait three weeks until pistons were manufactured. So I had some time on my hands. Since the owner had to wait, and I had nothing to do, my hands got itchy and I went in and did a little mild port work in the bypass side. Nothing major, just trumpet shaped the ports with a Dremel to ease gas flow and give the engine an "edge". Replaced 4 pistons, head gasket, exhaust chest gaskets, fuel pump diaphragm, water pump impeller, and replaced all exhaust cover screws with stainless. Cleaned carbs and set floats a little high on the premise that it is better to run a little rich than a little lean. Timing link looked wrong so I re-set it to where I thought it should be. Owner said speedo never worked so He did not know what speed he had before problem, but engine ran at 5,000 rpm. I blew out the pitot tube.
Went to the river with the owner. Engine fired first time and although it ran a little rough, it settled down when it cleared the assembly oil. YES! It was going to be a good day! This one was behaving itself.
Took the boat to the shallows where there was no traffic and checked timing Dead on 30 deg at WOT. That's dumb luck. ran slowly for a while to build up some oil then checked speed with owners original prop on short high speed run to 40 mph at 6,000 rpm. Changed prop to my 19 pitch stainless. One more high speed run to 47 mph at 5,400 rpm. Never bothered to check any other props--that's the one. Ran the rest of the tank out at about 3,000 rpm. Engine was just humming.
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