MCM525SC Cutting out
06-10-2012 | 01:18 PM
#11
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Joined: Aug 2006
Posts: 2,461
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From: Ontario, OH
Had one awhile back that was the rev limiter, but it would take longer than 20 minutes before it would restart.
The motor would run fine, and then the interval between initial start-up and the time the motor began cutting out became shorter and shorter. It was hard to find at first because only one of the motors (twin setup) actually had a rev limiter, the other one that I had torn apart previously did not so it wasn't until I started swapping electronics that I found the rev limiter. Once I swapped that over, the problem followed.
This was on a HP500 with Thunderbolt IV ignition. The cable harness that runs from the coil/ignition module/distributor sensor without the rev limiter was NLA so I had to cut out the rev-limter and splice the harness back together looking at the other motor. After that, no more problems.
The motor would run fine, and then the interval between initial start-up and the time the motor began cutting out became shorter and shorter. It was hard to find at first because only one of the motors (twin setup) actually had a rev limiter, the other one that I had torn apart previously did not so it wasn't until I started swapping electronics that I found the rev limiter. Once I swapped that over, the problem followed.
This was on a HP500 with Thunderbolt IV ignition. The cable harness that runs from the coil/ignition module/distributor sensor without the rev limiter was NLA so I had to cut out the rev-limter and splice the harness back together looking at the other motor. After that, no more problems.
06-10-2012 | 09:11 PM
#12
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Joined: Jul 2009
Posts: 8,527
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From: Taunton Ma
Rev limiter died on mine and caused intermittent no spark. I am replacing it with a standard tbiv harness tomorrow. Chased this for 2 weeks, boat wouldnt run on the water but ran fine at night when I got it home. It's mounted behind the ign module and I didn't even know it was there
06-18-2012 | 07:49 AM
#13
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Joined: Jun 2012
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From: Chester, CT
Hi -
Finally got the chance to run the test. I have spark, ignition checks OK so it must be fuel. Before I went out, I changed the fuel filter. Dumped the fuel from the old one in a glass jar and it looked fine - no water. I will install a fuel pressure gauge for my next test. Any suggestions?
Finally got the chance to run the test. I have spark, ignition checks OK so it must be fuel. Before I went out, I changed the fuel filter. Dumped the fuel from the old one in a glass jar and it looked fine - no water. I will install a fuel pressure gauge for my next test. Any suggestions?
06-19-2012 | 06:26 AM
#14
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Joined: Jun 2012
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From: Chester, CT
I took her out with a timing light hanging off #1 and when she stumbled and quit, the light was still flashing. Cranked her over and the light still showed I had spark. So it must be fuel. Before I went out, I changed the fuel filter and inspected what was in the old one. No water or sediment, and my fuel is fresh. I will put a fuel pressure gauge in and see what I have. Any thoughts other than that?
Thanks!
Thanks!
06-19-2012 | 08:18 AM
#16
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Joined: May 2012
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I had an old boat that would run for a while, then starve for fuel and die. After a bit it would start again, chased and chased the problem, ended up being a small piece of blue tarp (no idea how it got in the tank) in the gas tank getting sucked up against the check valve on the tank fitting.
Just trying to think of possibilites for ya
Just trying to think of possibilites for ya
