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Compression test results '82 Merc 470

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wrestling_coach

Contributing Member
Well I got a lot done the past few days. Oil changed, Pertronix ignition installed, new NGK plugs, 8mm wires, cap and rotor, set timing at 6* BTDC. Starts and idles on the trailer with the muffs just fine. Sounds good.

Compression test on a warm engine.

1- 150
2- 145
3- 150
4- 145

I think that is as much as I could expect and am happy.

Here is a shot of my gauges after idling for about 30-35 minutes. Less than 150* water temp.

DSC03120.jpg



Thanks everybody for your help getting this done.

Dennis
 
Compression looks great!!

volts are too low and rpms are too high

you should be around 14 volts

and 700 rpms.......

I would like to see 40 psi oil pressure also..at 1500 rpms......
 
kghost: Shouldn't the temp gauge run around 160 F. w/closed cooling? Maybe he's running a 140 T'stat instead of a 160F.
 
close enough on COLD WATER no load,,,,,,,,I bet the hose water temp is low 50's or less...Once in a lake in summer it will warm up..


could be the guage is slightly off......

I would not complain!!
 
Nice! Looks about like mine after idling that long, still have to get an alternator to charge but as far as everything else looks very similar. What kind of boat do you have it on?
 
kghost said:
Compression looks great!!

volts are too low and rpms are too high

you should be around 14 volts

and 700 rpms.......

I would like to see 40 psi oil pressure also..at 1500 rpms......
Click to expand...

Ah yes the volts. Still on the stator charging system. At times the voltmeter will read 15 and then drop back to 11 only to jump back up to 15 again. It spends most of its time at 15. It has me concerned. I want to see how it behaves on the water I guess. I have not yet adjusted the idle since I reset the timing at 6* BTDC. I'll drop it back to 700 RPM.

Dennis
 
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guyjg said:
A jumping voltmeter is a sign the voltage regulator is beginning its funeral.
Click to expand...

I was afraid somebody would tell me that. Thanks for the heads up. I've looked at some of the conversion kits on line. I have no power steering and I think I want the low mount design. I like the Breezeworks kit.

Dennis
 
Take a good look at the alternator being offered. Some of them off a "new" cheapo import that are not as reliable as a remfgr. marine alternator.
 
Hi, I agree with Guy on the status of your VR, but would add that it is already in the ground and buried. Don't go on the water without doing the conversion to an alternator and would suggest you stop running it this way as at 15 V you are killing your battery and if 11 V is right is well discharged. I have been running a Breezworks conversion for 5 years with no issues on starboard engine with low mount as that engine has power steering. I would suggest a high mount as you keep an electrical component up out of the bilge splash area or a partial flood level, i.e. fills up with rain on your trailer. My low mount is pretty low on the engine. I would echo Kghost on temps, my two don't warm up until they start working off idle even in warm/hot water temps, then it stays up on temp. I have 4" exchangers for reference.
Nice looking boat.
 
mark_searay said:
Hi, I agree with Guy on the status of your VR, but would add that it is already in the ground and buried. Don't go on the water without doing the conversion to an alternator and would suggest you stop running it this way as at 15 V you are killing your battery and if 11 V is right is well discharged. I have been running a Breezworks conversion for 5 years with no issues on starboard engine with low mount as that engine has power steering. I would suggest a high mount as you keep an electrical component up out of the bilge splash area or a partial flood level, i.e. fills up with rain on your trailer. My low mount is pretty low on the engine. I would echo Kghost on temps, my two don't warm up until they start working off idle even in warm/hot water temps, then it stays up on temp. I have 4" exchangers for reference.
Nice looking boat.
Click to expand...

You must be psychic!! I talked to the Breezeworks guy early this morning. He was driving across the Mojave desert in Cal. on his way to Edwards Air Force Base. I'm not making this up. Low mount kit is being shipped from Wisconsin tomorrow. Thanks for your input. I'll have more questions installing this kit.

Dennis
 
Well I spent the morning installing the Breezeworks alternator conversion. Nice conversion kit. Fit perfectly. Started boat up and ran it for 30 minutes on the trailer. Voltmeter holds a steady 13.5 volts at 700 RPM idle. No more voltmeter jumping from 10 amps to 16 amps and so on. For my application I had to grind a bit of the adjustment bracket to clear my doghouse. I also swapped the belt for one that was one inch shorter to get the alternator away from the doghouse a bit. I feel much better now. Thanks all for your help on this and other items so far. You're the best.

Dennis
 
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It came complete with a pre-made wiring harness. Plug and play! Now let me make a little tongue in cheek comment. One of the first things people poo-poo about these engines is the stator charging system. Well this one is original and it lasted 29 years. Just sayin'.

Dennis
 
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