Where to start

[gatrboy52]

I acquired a 97' 200 efi. Power head was rebuilt. Oil reservoir removed ( must add oil to gas, advanced timing module removed. . supposedly replaced impeller. Boat/ motor has been sitting 8 months. Owner says he cranked it on muffs a couple times over that period. I put fresh gas 10 gal. And a qt. Of oil, and pint of sea foam and it cranked right up. Ran fine. After 10 min. Steady alarm came on. I shut it down waited 30 seconds restarted... No alarm. Ran at 3000-35000 rpm for a other 10 min. Alarm again. ( 12 psi at idle,15 psi engaged, 20 psi at 3500 rpm. ) shut down and immediately restarted... No alarm. Repeat as above. When alarm came on I left engine running maybe a min before shutting off then restarted immediately and no alarm. Pulled bowling heard no steaming or crackling as if engine was hot. Then the last 15+ min of my break in run no alarm. Next day only one alarm during break in perod. I would think if it was impeller my psi would be weak. I'm thinking it has something to do with disconnect of oil pump or the power packs Any advice appreciated.

[JOE54]

module should have been deleted at time of oil pump removal , would chech all components of cooling system starting at pump and all 3 gaskets , all psi sounds lil high to me , inspect poppet for sticking must be butter smooth

[leonreno]

Listen to Joe, that psi is high. I would also check thermostats, sometimes people remove them trying to fix a problem are they could be stuck closed. But since this motor is new to you and sat for 8 months, I would consider replacing the pump, even though it seems to be high pressure. On a fresh rebuild it’s also possible a gasket has failed and exhaust gas is entering the water jacket.

[JOE54]

make sure your gages are accurate

[gatrboy52]

Read original post

Replaced water pump
Water pressure gauge is not accurate
Motor pees ...stronger as accelerating
Still in breakin, so I run 3-3500k rpm
At this rpm I can run 30 min+ before alarm
If I take it up to 4 k around 10 mins before alarm
My observation:
Motor does not appear to be overheating.. No steam,no crackling and as soon as I shut motor off and immediately crank back up..no alarm
At 3-3.5k I don't seem to get alarm. At 30 min run time
As soon as I push up to 3.5-4k around 10 min.
Thermos seem to be operating properly but I can replace those.
? How do you check a poppet for proper function
What to check next?

[JOE54]

i would remove poppet and verify all components are there and installed correctly and butter smooth ,may want to do leak down test to check head gaskets also , make sure all warning module wires disconnected , oem thermostsats , hose from poppet to top of block not restricted