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  #1   IP: 174.119.148.66
Old 08-29-2011, 07:09 PM
nreeves nreeves is offline
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Intermittent shifts in power/revs

Just finished our first three week trip on our boat. Motor ran beautifully, except the rpm's would occasionally drop slightly for 10-15 seconds, then resume at the set speed. You could hear the motor rev down, then back up. Curious what that could be. Carburetor? Air in fuel line?

A second question is that I finally plumbed in my racor fuel filter, and had it running fine the whole day after the installation. The next day, I could not get it to start until I bypassed the fuel filter. My guess is that the filter was not completely filled and there was air in the line. I have an electric fuel pump after the filter and can run it manually, but am worried about running it to long. Is there any risk of flooding, or tips on how I can bleed the fuel filter line to get it running properly?

The filter is 4" below the feed line from the tank, then another 8-10" to the electric fuel filter. Does that sound right?
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  #2   IP: 24.136.67.99
Old 08-29-2011, 09:58 PM
Dave Neptune Dave Neptune is offline
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Lightbulb Air leak?

If this symptom started just after instalation of the Racor I would suspect an air leak at a fitting, hose clamp or the spin on itself. Give the lines a "twist" by hand and if it moves easily it could well be the culprit. Be sure and check them all, it doesn't take much of a bleed to interupt the fuel flow enough to slow things down and as they are slowed down the carb fills back to where it should be and the RPM's go back and so on and so on.
Before you start looking elsewhere confirm your fittings and the cartridge itself.
Get back if you find nothing in the fuel lines.

Dave Neptune
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  #3   IP: 208.89.140.11
Old 08-30-2011, 06:51 AM
smosher smosher is offline
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What Dave said

Sometimes with air leaks in the gas line, gas will seep out of the joint when it hasn't been in use for awhile. Any hint of gas when you stick your head into the cave ?

The installation itself sounds like mine for a pearson P30. Gravity will fill the
filter and lines up to the fuel pump when the petcock is opened. What fuel pump part number are you using ?

I have a manual fuel pump with a fuel pressure gauge and it sits at 3 1/4 lbs psi when running.
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  #4   IP: 74.198.87.39
Old 08-30-2011, 04:11 PM
nreeves nreeves is offline
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I have installed a racor fuel filter that I bought from this site S3228UL.

I will check for air leaks, but have not noticed any leaking fuel and have double clamps on each end. Air in the line seems like the most likely cause and I will tinker with it this weekend.
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  #5   IP: 173.54.181.116
Old 08-31-2011, 09:26 AM
rheaton rheaton is offline
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I installed an inline outboard style pump. This helped me locate a leak.
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