Seaducer/Mac questions??

[Keebibear]

Ive ran this combo a couple times and its gotten frustrating and need to see what others think might be a next step.Im running a SD3 with a Mac21/Mac parapolic pipe.Ive just put a new sleeve and piston (due to over heating earlier this summer) so the motors still new but heres what happens.

I ran it for about 3 tanks with a 437/3, ran ok, pipe at 8 1/4 and very rich.Head pretty cool after 8 or 9 laps.Also a very humid hot day.

Today I tried a 440/3 ran fast as hell but fell off the pipe after 3 laps and once brought in was very warm.I tried the pipe from 8 1/4 to 9 inches,raising the strut,and so rich it doesnt run right but still heats up HOT!

Ive ran this setup before with a new Mac and Seaducer and had the same problem.Started earlier this year with 65% wildcat and have Sig 55% fuel now.Any suggestions?Maybe a modded prop?Go back to the 437 and lean on it?Thanks

 

[Rick Cesati]

Keebibear,

Go back to the 437 the 440 is too much. Leave the boat rich and squeeze the pipe...I would start at 7-7/8" and maybe go down another 1/8 to 1/4. Which version parabolic are you running? Stay away from the S for your mono and run the original or long. We are still working with the FAT pipe so can't help with that one. IMHO all MAC21s should be <8" period.

Rick

Ive ran this combo a couple times and its gotten frustrating and need to see what others think might be a next step.Im running a SD3 with a Mac21/Mac parapolic pipe.Ive just put a new sleeve and piston (due to over heating earlier this summer) so the motors still new but heres what happens.I ran it for about 3 tanks with a 437/3, ran ok, pipe at 8 1/4 and very rich.Head pretty cool after 8 or 9 laps.Also a very humid hot day.

Today I tried a 440/3 ran fast as hell but fell off the pipe after 3 laps and once brought in was very warm.I tried the pipe from 8 1/4 to 9 inches,raising the strut,and so rich it doesnt run right but still heats up HOT!

Ive ran this setup before with a new Mac and Seaducer and had the same problem.Started earlier this year with 65% wildcat and have Sig 55% fuel now.Any suggestions?Maybe a modded prop?Go back to the 437 and lean on it?Thanks

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[Keebibear]

Pipe is the long version.Thanks

 

[Eric Canto]

I do not think the 440/3 is too much prop. What is your stinger I.D.? Are you taking any plugs? What kind of plugs are you running? Have you put enough run time on the new P/S for it to be well broken in? These symptoms are also typical of a head clearance that is too high.

Eric Canto

The Speed Shop

 

[Roxyflash]

Is it been drilled out?The pipe.Getting good water flow all the time?

 

[Keebibear]

Ive been running Mcoy mc 9 plugs and I dont think the plugs have blown unusually.No the pipe hasnt been drilled,I cannot fit a 1/8 inch bit through the hole or on my other AB pipes.theres really good water flow through the head and out the side.Ive drilled the fittings and run larger hose for cooling.The motor was well run but still had great compression and good bearings when I first recieved it from a fellow board member earlier this year and I had this problem then.Ive had this exact setup before with a different motor Mac 21 and hull Sd2 and the same problem.Thats why the questions.Someone mentioned that up here in Minnesota the water is denser or thicker thus running a lesser prop.Ive also had similar issues with other boats not running on the suggested prop but a size down worked fine.