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88inNH
08-24-2013, 12:57 PM
1988 Prostar 190
Ford 351
Conventional ignition / points (needs a tuneup)

Engine will occasionally "cut out" while driving (goes dead electrically as if I had turned off the key). Assumed grounding problem of some sort but figured I'd check my "marginal" battery and alternator before pulling the dash apart, etc.

Opened engine cover / hood with engine running and noticed a fine mist. Turns out water is dripping from the shaft behind the Raw Water Pump. The water drips right onto the pulley / fanbelt behind/below it and gets sprayed onto the front of the engine / alternator / fan belt, etc. Thinking back, I may have heard fan belt slipping in an engine "cut out" episode.

I likely have multiple problems going on here. But is seems like eliminating water spraying on the belt / alternator might be a good starting point.

Question #1 - Any ideas on the drip on the shaft behind the raw water pump? To be more accurate, there are slots in the casting of the raw water pump where you can see the shiney shaft spinning. The water is dripping out there (so I guess technically the leak is in the pump. It's just not up front where the impeller is. Is this a seal / gasket or failed pump? DIY?

Question #2 - What are the chances that the spray and slipping belt is causing the electrical problem?

Question #3 - If not, any hints on tracking down the electrical? My plan is to just disconnect / clean / reconnect everything I can get at (behind dash, battery, alternator, starter / solenoids). Anyone ever put together a list of what to check and what order? I've got a DVM - is it worth taking readings or just better to clean everything?

Question #4 - The boat runs ok otherwise (other than needing a tuneup). Temperature fine, etc. Voltage at battery is ~12.45, jumps to ~13.45 when running (volt gauge in dash reads about 1.5 volts lower). Is it bad to run it like this with the occasional cut out?

Thanks

waterlogged882
08-24-2013, 01:35 PM
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88inNH
08-24-2013, 03:23 PM
@Cloaked
Thanks for the quick reply. I'll attack as two separate issues: pump and ground.

My pump says Johnson Pump F6B-9.
Agree - $185 vs $110 seems a no-brainer.
Where did you get yours (PM me if it's inappropriate to post sources).
Does pump just slide off after unbolt (3 allen bolts on pulley behind it, bracket) or is some sort of "puller" involved?


Out of curiosity: Anybody ever rebuild a F6B-9? Does it takes more than an hour or require special tools?

Just thought I'd toss that back out for comments/hints while I start cleaning connections.

mikeg205
08-24-2013, 03:32 PM
@Cloaked
Thanks for the quick reply. I'll attack as two separate issues: pump and ground.

My pump says Johnson Pump F6B-9.
Agree - $185 vs $110 seems a no-brainer.
Where did you get yours (PM me if it's inappropriate to post sources).
Does pump just slide off after unbolt (3 allen bolts on pulley behind it, bracket) or is some sort of "puller" involved?


Out of curiosity: Anybody ever rebuild a F6B-9? Does it takes more than an hour or require special tools?

Just thought I'd toss that back out for comments/hints while I start cleaning connections.

Bunch of people have rebuilt their pumps... check this thread - post #2 has direkshuns... ;)

http://www.mastercraft.com/teamtalk/showthread.php?p=168509#post168509

waterlogged882
08-24-2013, 03:34 PM
..........

BG1772
08-24-2013, 07:22 PM
If you have a bench vise and a deep well socket of the same size as the bearing, it is pretty easy to rebuild.

MikeyOrange88
08-24-2013, 07:24 PM
I had similar problem when my water pump failed. Engine was running extremely poor (never having done that prior), raised the engine cover and saw water spraying everywhere from broken pump (rear of unit). Purchased and installed new water pump and no further issues with the engine missing.
Definitely treat water pump replacement as step one. Changing water pump is straight bolts off, bolts on replacement. Good Luck

waterlogged882
08-24-2013, 07:27 PM
..........

mikeg205
08-24-2013, 07:28 PM
i am in the replace it all camp too... especially this part...

Lumbergh
08-24-2013, 08:32 PM
My Johnson pump was leaking at the aft end.

Pulled pump, new $25 seal and reassembled.

Easy job, maybe 30m work. I wrote it up with pics and so on a few months ago. Maybe search for it...

My local (expensive) boat shop wanted to replace pump too when I got seal from them. I am sure that would have been a $500 job for my 30m worth of work and a seal.

YMMV of course.

scottpiper27
08-26-2013, 11:02 PM
Hi 88 - My ski partner has the exact year and model and had the exact same problem last week. Water pump leak at the back, water vaporizing off the belt, causing the carb to gag. We tried replacing the seals but it didn't work well. Then we just sucked it up and spent a couple hundred on the whole new pump, easy install, now runs like a dream. The others above may be more skilled and knowledgeable than I, but I would just go for a new pump. Good luck.

88inNH
05-27-2014, 12:27 PM
Just to follow up / close this out for the next guy:

I got tremendously lucky tracing the "cutting out" issue. I started at the key / ignition (since episodes felt like key was being turned off). Pulled the dash and immediately found a loose terminal on the ignition switch. I assume bouncing over waves was causing it to break contact. Tightened down / problem gone. Better to be lucky than skilled, eh?

Also, ordered the whole raw water pump. Plan to install this weekend.