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-   -   502 mpi hours before refresh? (https://www.offshoreonly.com/forums/fountain/323661-502-mpi-hours-before-refresh.html)

Diamond Dave 03-04-2015 02:51 PM


Originally Posted by ttuton (Post 4273856)
This was a 365HP 454 in a 92 straight bottom fever. The boat ran about 65mph with low hours and now runs about 60 even. I believe this is a flat tappet cam engine also. The newer engines are roller and should hold up even better.

That's good info thanks!

obnoxus 03-04-2015 03:15 PM


Originally Posted by Diamond Dave (Post 4273811)
Any idea on how much it changes things?! Just trying to get a feel for the abuse I can dish out myself as a new owner as I have no experience... lol

Don't be afraid to run your boat,,,,, but to pin it wide open with no regard for oil temp ( which you may not even have a gauge for ) and old / questionable quality oil is a recipe for failure.

The most common high hour failures engine I see come through the shop is blown head gaskets,,,, and normally after an overheat. I had a 38 Special with stock 502's and 1100 hours on it and it only dies because the owner refused to repair the old VST fuel system.

Run a good oil, Castrol HD 40, Valvoline VR1 40 ,,,, Rotella makes a great high Zinc content oil, ETC,,,,,,,,, keep it clean and enjoy !!!

Hook'em 03-04-2015 03:45 PM

His being a '97 it likely is a VST set up (as is mine). Would you care to expand on your comment concerning VST? Trying to learn something here. Thanks.

SB 03-04-2015 04:13 PM

VST = Very Stupid Thing. Ha !

Dan27 03-04-2015 04:24 PM

Like others said as long as it has been maintained well you should be good to go. My '95 has 700 right now and I'm not planning on a rebuild anytime soon (I hope lol). But the previous owner had all maint done at the Fountain dealer by the same tech it's entire life until I purchased it so I know it has had a good past.

F-2 Speedy 03-04-2015 04:42 PM

All you high miler's chime back in when you spin some bearings due to low oil pressure cuz the oil pump is wore out or worse yet a window in the side of the block, my engines also ran great and when I pulled my 502 MPI's apart at 600 hours, they were wore slick, I could shoot carb cleaner into the intake runners and watch it come out the valve seat same with the exhaust. Over a period of years you don't really notice a big decline in power because its gradual. So good luck, run r till she blow's

Diamond Dave 03-04-2015 04:42 PM


Originally Posted by obnoxus (Post 4273900)
Don't be afraid to run your boat,,,,, but to pin it wide open with no regard for oil temp ( which you may not even have a gauge for ) and old / questionable quality oil is a recipe for failure.

The most common high hour failures engine I see come through the shop is blown head gaskets,,,, and normally after an overheat. I had a 38 Special with stock 502's and 1100 hours on it and it only dies because the owner refused to repair the old VST fuel system.

Run a good oil, Castrol HD 40, Valvoline VR1 40 ,,,, Rotella makes a great high Zinc content oil, ETC,,,,,,,,, keep it clean and enjoy !!!

I have oil gauges and watch them for sure! I plan on trying the VR1 when I change oil next also heard good things about it but not sure what weight is best.




Originally Posted by Hook'em (Post 4273909)
His being a '97 it likely is a VST set up (as is mine). Would you care to expand on your comment concerning VST? Trying to learn something here. Thanks.

Yes please! Mine is a 95 and if there is some upgrade to help it live longer I'm all in!! DO TELL!

ROB FREEMAN 03-04-2015 06:40 PM

id redue the heads .. upper rebuild ..in the off season .. im guessing theese 1000 hrs are fresh water motors .. thats alot of hrs .. i wonder why people always stay away from boats with 500 plus hrs on them . at least everyone says they arnt worth as much with such hrs on them ... sorry for disagreeing .. im guessing theres few with that many hrs . compared to the many failures well below that mark ... leakdown ...

Crude Intentions 03-05-2015 06:23 AM

Friend here (Oneanddone) has over 600 hours on blown 454s. 1991 boat and motors. Bottom ends have never been out of the boat. Top ends done in the past but stock bottom ends. Boat runs like a dream. Mixture of fresh and salt it's whole life.

buck35 03-05-2015 10:11 AM


Originally Posted by Diamond Dave (Post 4273940)
I have oil gauges and watch them for sure! I plan on trying the VR1 when I change oil next also heard good things about it but not sure what weight is best.





Yes please! Mine is a 95 and if there is some upgrade to help it live longer I'm all in!! DO TELL!

Vst is a vapor locking device merc put on to the hours down. Jk
Do a search, many many threads.


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