Spring tune-up, engine idle @ 3k rpm, battery at 16.5v, engine runs @ 182.5 F

[capslock118]

Hi All,

This post may be an over analysis and a waste of time but I just wanted to summarize my observations in case something doesn't sound right here.

The engine turned on immediately, hooray!

Few things that I noticed were:
1: The engine was idling at 3,000 RPM. I THINK i remember idle last year was somewhere around 1500 to 2000 RPM after my local mechanic tuned the engine up. Does this sound normal or where can I go to answer that question (1990 V6 135 HP blackmax)?
2: The engine ran a 30sec to a min before the water impeller kicked in. I thought this was an unusually long time, but it seemed functional once it started going
3: The engine heated up to about 182 degrees F. I THINK I remember the engine running less than 145 degrees last year (145 is the center of the temp dial) but maybe I either forgot completely OR the hose water was not cold enough, either way it was stable at 182 at idle temps. The overheating sound starts going off at 220 and it didn't get that hot.
4: The battery was @ 16.5v when I finally shut the engine off I'm not sure, but I feel this is high. I thought batteries ran at 12 or 14v? It's a brand new deep cycle battery 1000 cranking amps 105 reserve min. I wasn't paying that close attention but I thought the battery was at 14v when I first started the engine. That said, is the engine running at 3k rpm idle because it's working hard to charge the battery? If so is it overcharging it and is that potentially dangerous?


Spring tune up this year consisted of:
-New fuel pump diaphragm
-New fuel/water separator (boat never had this installed before)
-New fuel line
-New tc-w3 oil (west marine)
-New lower-unit oil


Thanks for your reviews

 

[Jacket4life]

Re: Spring tune-up, engine idle @ 3k rpm, battery at 16.5v, engine runs @ 182.5 F

My 2 cents on what (little!) I know:

1. Idle sounds high. Don't know how long you ran it. If you ran it very short time, not that unusual. Let it run 5-10 mins and see what you get. Better yet, take it out and RUN it WOT a little while and see what it does.

2. Not that weird for first start of the season. Mine always takes 15-20 seconds to start peeing.

3. Seems a LITTLE warm. I beleive your motor has T-stats. May want to change them since you seem very thourough. I COULD be wrong bout the T-stats.

4. Battery voltage seems high, you need to check it while the motor is running. If it's more than 18, I'd get it checked out, it is overcharging.

Goood Luck this year!

 

[capslock118]

Re: Spring tune-up, engine idle @ 3k rpm, battery at 16.5v, engine runs @ 182.5 F

Let it run 5-10 mins and see what you get. Better yet, take it out and RUN it WOT a little while and see what it does.

It ran for about 5min i'd say today with those results. Once I get my trim anode fixed (other post) I'll be putting it in the water where ill be running WOT.

I beleive your motor has T-stats. May want to change them since you seem very thourough. I COULD be wrong bout the T-stats.

It does have them and I was going to replace them this year but I'm already over budget for this year; replacement will have to wait until next year unless necessary.

Battery voltage seems high, you need to check it while the motor is running.

It was running at 16.5v. It will take 30min or so at WOT to get to the harbor from our launch point and we usually go for a stroll at the start of the season so...not sure on this one. Maybe let the engine run for 15min on shore to see what happens. It's an AGM sea-volt deep cycle

 

[Jacket4life]

Re: Spring tune-up, engine idle @ 3k rpm, battery at 16.5v, engine runs @ 182.5 F

Keep in mind I am NO expert! Just kind of know your results compared to what mine does...When mine is running, the battery voltage is about 16-16.5. There is no regulation from your rectifier, so, that is what I am used to seeing. It's just that mine drops to 13.5 or so when the motor is off, that's what I thought you said originally, guess I misunderstood.

The T-stats are fairly cheap aren't they? Seems like good insurance for the money, but I know how being on a budget is too...

Best of Luck!

 

[Jacket4life]

Re: Spring tune-up, engine idle @ 3k rpm, battery at 16.5v, engine runs @ 182.5 F

Oh, and also, was that tach reading from your dash tach? Stupid question maybe, but does your tach return to zero when the boat is off? My Dad's tach went bad a couple of yrs ago and (stupid us) we started trying to tune the motor before figuring out the tach was the problem!!! His, when you shut the boat off, would "hover" around 600 RPM on the gauge. So when you ran it, it was reading higher tachs than what the motor was really turning... Just thought I'd ask...

 

[capslock118]

Re: Spring tune-up, engine idle @ 3k rpm, battery at 16.5v, engine runs @ 182.5 F

There is no regulation from your rectifier, so, that is what I am used to seeing. It's just that mine drops to 13.5 or so when the motor is off, that's what I thought you said originally, guess I misunderstood.

Not sure what a rectifier is. I must be getting confusing and I tend to do that. Just before I turned the engine on, I THOUGHT I remember the battery being somewhere in the 14v range. Just before I turned the engine off after running for about 5 min, it was at 16.5v on the dial.

Oh, and also, was that tach reading from your dash tach? Stupid question maybe, but does your tach return to zero when the boat is off?

Yes to the first question. Answer to the second question: Not immediately. If I just turn the engine off no. However if I turn the engine off and then turn accessory power back on then yes.

His, when you shut the boat off, would "hover" around 600 RPM on the gauge

This would reinforce my above answer. That is not what I am observing.

However, last year I was told that the electronic gizmos that were regulating the pistons were starting to go bad and would give me false reading on the tach. I was told they (stator?) need to be replaced at some point. However, in this case the engines SOUNDED right for 3k rpm. Thats how i felt about the sound anyways,