Cockingoff

I replaced the impellers on my 2007 Formula Fastech (acquired it about 6 months ago). Decided to carry out a "200" hr maintenance. Boat was running perfectly prior to my decision to do the maintenance. Replaced the impellers but did NOT replace the very scored stainless back plate (have "run aground" into sand at idle in shallow water twice), nor the impeller housing (yep, stupid beginner's mistake). Started up the motors and neither motor created great water pressure (about 1.8 psi at idle, used to idle at 3.8-4 psi). I shut the motors down almost immediately as I felt the new impellers were not "priming". Damn it! Waste of 5 hours. Read this forum and realized I should have replaced the housing and back plate and little o-ring (seems crazy that such small scoring can have that much of an effect on priming "suction". So I got two new impeller kits and will place on boat tomorrow.

My questions are the following:
1) How fast should the motor prime with water after changing the impeller (and housing and back plate) and dry starting ?
2) Is there anything I should do to prime the fuel system as I removed the seapump/fuel pump lines this time (first time I removed the impeller housing without removing from motor and didn't mess with the fuel lines....bad way to change the impeller, a real pain in the ass, hands, wrists, fingers and abdomen/chest too.)
3) Since I have a "newer 2007 motor", I have the closed heat exchanger system with the fresh water plug in at the top of the motor for flushing. Should I use this system to start the motor the first time, or should I allow the motor to "pick up the water" from the bravo out-drives?? Would the fresh water flush system make for a "less dry start" for the new impeller?

Lastly, thanks to the forum! Brand new to site and love all the information and how to's. Has been a tremendous help (Wally's how to impeller change was great, wish I had read that first!)

bajahammer21

shouldn't have anything to worry about i personally like to grease the inside of the water pump housing to eliminate dry start up not a ton just a fine layer of grease any kind of grease just don't use like quicksilver 101 with teflon hahaha

Expensive Date

Fuel system is self priming so you are good there. The small plate if its what I think you have needs to be changed, a little scoring will cause what you described. Reason is the old impeller was seated in to the groves so probably sealed a little better. As stated always put grease or soap or transmission fluid on the impeller. The flush ports would be the best to use when running, don't worry it will be faster the second time.

indysupra

I always lube them with silicone paste.

Pwraddr

I use Dawn dishwashing soap.

boatnt

yep,,and when you started up you know they are circulating by the soap suds in the back of your boat..

VoodooRob

Take the entire sea pump/ fuel pump off this time. It's just a couple more steps. The mechanical fuel pump needs to be inspected for wear from the lobe AND the fluid which will be saturated with fuel needs to be drained and filled with outdrive lube. Do this every season to extend fuel pump life. Many owners change the fuel pump while doing this if it's original. Mine were heavily scored from the lobe on the armature because of fuel diluting the oil. Once this is all complete, you can use a mityvac to pull the fluid out or tap a drain at the bottom of the little oil "case". Sea strainers will stop all debris (small like sand) from getting in the sea pump but they will help, it's a thought to consider.

Pwraddr

The other thing for me Tom is that my daughter swims in the lakes and my friends fish in them.....I don't want anything in it that shouldn't be.

Cockingoff

Thanks all for the replies! I took the whole unit out this time (much, much easier) and already changed the oil in the little fuel pump reservoir too. Didn't notice any gas in it, I suppose that's a good thing. Will put everything back on in the next few days and see how it goes.
Thanks again.

HyFive578

I always replace the whole pump kit every time, not just the impellers for the reasons already mentioned. Also, when seating the impeller in the housing, it's better to use soap or a water-based lubricant... grease/oil-based lubes can degrade the rubber. Also, this may be obvious, but make sure you orient the vanes in the proper rotation. Nothing to do on the fuel system, just reconnect.