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wmachovina
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Post by wmachovina »

just splashed Seachele w 250 cummins(700hrs) dreaded cpl953, 20x23 4 blade port engine 2650 stbd 2520(aetna tachs) but suspect stbd thermostat-only 130 degrees port at 180. 28-29 kts wot 24 at 2200. Amazing torque. Uncle Vic, plz chime in, Bill
Bill
IRGuy
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Post by IRGuy »

Bill...

When I bought my boat the temps on both engines ran about 15F high.. this continued even after I had both systems flushed and cleaned with Ridlyme solution and replaced both raw water pump impellors.

I bought a $50 infrared non-contact thermometer from a local HVAC supply house.. and checked the temp of both blocks next to the temp sensor.. both engine temps were normal on the handheld thermometer. I replaced both sensors and gauges.. and both showed normal temp.

I would suggest you buy one of these thermometers and check as I did. You might have faulty temp gauges and/or sensors.
Frank B
1983 Bertram 33 FBC "Phoenix"
--------------
Trump lied! Washington DC isn't a swamp.. it is a cesspool!
wmachovina
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Post by wmachovina »

temps were checked via ir gun,I do think we have a bad thermostat , will check monday. the engine sat for a long time -700 hrs on a trawler in Lake Erie 1989 build- not alot of use- hope to rectify that :-)
Bill
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In Memory of Vicroy
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Post by In Memory of Vicroy »

Bill - you are at the sweet spot. Remember that a 5% plus or minus is "factory spec" on rpm and most other parameters. The stb. thermostat is probably stuck open....it may "fix" itself with a little running. The thermostat is not real easy to get at, so run it a while before you rip into it.

Your 2650 is the target, but a little more is fine. Your speeds are right on the mark. Good job. Run 'em at 2400 all day long, they love it. If you have not overhauled the Sherwood 15000 series raw water pumps with Tony Athens' stuff, do it. About the only thing that will hurt the 250s is a gross overheat.

UV
wmachovina
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Post by wmachovina »

UV -thanks for the note,gonna change the thermostat tomorrow-when we put the engine in we left 8 inches in front,plenty of room,did put in fresh impellers, will go to Tony"s upgrade soon,I was just spent($). considering the age of the motors I don't mind changing a few things, like a new lift pump that was weak.I can see these engine don't like air in the fuel!! Bill
Bill
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In Memory of Vicroy
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Post by In Memory of Vicroy »

I sure wish I had 8" in front of mine...maybe 2"....yeah, they airlock in a heartbeat, and when they do, get out the book & bleed in the book sequence or you may get them started til next August.....A 100% tight, air free fuel system is essential. I crank mine about every week and since I put the block heaters in they start instantly no matter how cold it is, a far cry from grinding on the starters before. They don't like to start at ambient tmeps below about 50 F. without external heat.

I love my old 250s....mine were built in November, 1989 and still run just like new. Clean air, clean fuel, clean oil, keep the rust off 'em and there is no real end-life hours for them.

UV
wmachovina
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Post by wmachovina »

Yeah these are early 89 builds I know it was risky but the price was right and they looked to be never used. I've got 4d agms and bam! as Emeril says , they start, no smoke or nuttin. I'll take luck over skill any day
Bill
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In Memory Walter K
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Post by In Memory Walter K »

Mine are 90's. You aren't going to find more dependable engines. They WILL smoke at start in cold weather (I'm in the NE) then once it warms up, it's over. Block heaters would solve that. Good luck! Walter
wmachovina
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Post by wmachovina »

Walter, thanks, usually here in S Fla. block heaters wouldn't be a consideration but thus winter has been cold,cold,cold. but 42 degrees doesn't seem to cause a start problem-I will though look at em if I have any problems though, Thnks Bill
Bill
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Bruce
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Post by Bruce »

Bill,
Saw your boat at AJ's last week when I was doing an engine survey.

One of the more prettier and well done 31's I've seen.
wmachovina
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Post by wmachovina »

Bruce, thanks for the compliment, yeah I'm pretty happy with the way she turned out. Changed thermostats today and got the temps up 180-Very pleased w the performance. 7 kts at idle leaves too much wake in Manatee pocket, one engine out of gear works good. 370s must be a bear close in. I'm getting 23 kts at 2100 and 29 wot :-D :-D :-D Bill
Bill
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In Memory Walter K
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Post by In Memory Walter K »

You can lower your idle to 650 and/or reduce pitch and add cup. The lowered pitch will slow you down at the low end, the cupping works for you at the higher end.
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