1970 Checkmate MX-14

[starviper10]

I apologize for the lack of updates here. Finished my internship last week and have been getting ready to go back to campus tomorrow so it's been a hectic week. But I did get the boat in the water and running. Should have time tomorrow to update with everything.

 

[starviper10]

I forgot to mention that I had some stud length issues because of this mid section. Four powerhead studs and one lower unit stud were too long. I ended up threading the coarse end until I had the length I needed, threw a nut on and cut it down to length. After I backed the nut off over the cut end, the threads were straightened out and they hand-threaded in. I'm realizing that this mid section has caused a large majority of my issues, and a regular 15" mid wouldn't have any of them. However, I've been able to solve them thus far and I think it's well worth it. I really like the look of the BP mid.

 

[1954bmw]

You said you got her wet, how did she run, any problems, what did you do about paint in the splashwell, gages, seats, controls, tell me everything

 

[starviper10]

Yeah so I got her in the water a week ago Saturday (8/19). Haven't painted it. The point was to get it running before I go back to campus. I'll pull the engine apart to paint it properly, and split the hull and deck for paint. There's some work on the bottom that really needs to be done before paint. I'd really like to learn how to blueprint it. As for interior, there isn't one yet. I will get two bucket seats for it. I really like the ones Will has on his V-Mate so I'd like to do something similar. I threw one of the merc controls I have on there. I would like to put a Morse MV-2 system in, with a push-to-choke ignition key in the dash. As for gauges, I currently have the speedo, tach, and 30psi water pressure gauge in that are the correct stock ones. The fourth gauge is a 15psi gauge that is hooked up. It's not the stock style because they don't make a 15psi version in that style. I think the tach hook up on the controls is not working, because I have a NOS tach that isn't working. I haven't checked with a probe yet.

 

[starviper10]

So when I launched it I had my parents in our Ski Nautique follow me on the way home from the ramp in case something happened. I had some issues with idling in gear. I had to give it some gas or it would die. I didn't get the power trim system completely installed and connected, so I ran it with the tilt pin in the 2nd position. In hindsight I should have it at the first position. When I went to get on plane the engine would rev up really high without any increase in speed. Initially I thought the rubber hub was spinning in the prop, as I had that happen with my 35hp Merc before. But I was shooting a big spray out, so I figured out that the prop was surfacing at this point because it was trimmed too high. The engine was still getting water to cool it because I had good water pressure. At this point I was attempting to get on plane slowly and not having a lot of luck, so I backed down and decided to just hammer it down and get through this point really quick. I still had a little time where it was shooting water, but I was soon on plane and it took off. Had to back it off real quick. It ran great from there. I was running like this for about a 1/4 mile until it just stopped running while on plane. After that I couldn't get it started. So my parents pulled me home. I had a feeling it was the fuel filters. After pulling a lot of stuff off the motor, I got to the fuel filters and found junk in the middle carb filter so it looks like it was a dirty tank. I was using a 3 gallon tank that I use for a 20hp and 35hp merc with a 5/16" fuel line. I was planning on getting a 6 gallon tank but hadn't got around to it yet. So I went out and got a 6 gallon tank and ran a 3/8" line direct to the fuel pump. She fired right up. Idled in gear, ran well on plane. I took it out quite a few times over the remaining days I had before I pulled it out of the water on Saturday (8/26). I went through at least 12 gallons of gas and it kept running well so I think I fixed the issue.

 

[1954bmw]

On my original mx-15, I could peg a 15 pound water pressure gauge with a 1971 115 Merc with a fresh water pump impeller, so I went with a 30 pounder, had to argue with the Merc dealer and asked if they would warrant the 15 pound gauge and they sold me the 30. Good luck, how did you manage to run all those course threads, bet that was a job????

 

[1954bmw]

Looks like she floats well, not too much weight in the back, oh to have young knees again, you did good!!!!

 

[starviper10]

Yeah I pegged the 15psi gauge as well. But when idling around the dock I like the accuracy of it. As to the threads, yes it took a while to get them down that far. I was afraid that it would be a real pain to cut the stud initially and start the threads from nothing. I did start to feel my knees after I ran through a whole tank in one run. Definitely looking forward to getting seats!