Aftermarket RPM meter on my Mercruiser

M

Mr_swordfish

Cadet
Joined
May 26, 2012
Messages
11
Dear fellow boaters,

I bought a Bayliner 215 classic from 2003. This boat has a mercruiser 5.0 and a alpha one gen 2 outdrive.
I noticed that the RPM meter has been replaced by an new one (blue inner housing and the rest has a white inner housing)

What I also noticed that according to the meter my motor has a rpm range of 1000 at idle and approx 8000 WOT. (meter ends at 7000)

On the back side of the meter is a potmeter of some sort to aldjust the amount of poles. At the moment it stands at position 3 that says 8 pole/cilinder. So that should be correct but my engine cant turn 8000 rpm I Guess.

Has anyone an idea?


Greetings from the Netherlands,
Martijn
 
achris

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Aftermarket RPM meter on my Mercruiser

Mr Swordfish,

Welcome to iBoats....

You need to select '8 cyl', not 8 poles/cylinder... The number of pulses per revolution on an 8 cylinder 4 stoke engine is 4....

Does the new tacho have a brand name? (and model number... I will track it down for you if I can)

Chris...
 
picklenjim

picklenjim

Chief Petty Officer
Joined
Mar 11, 2009
Messages
528
Re: Aftermarket RPM meter on my Mercruiser

The 5.0 has a max rpm at wot of 44-4800rpm. The meter is made to work with other engines also.
 
M

Mr_swordfish

Cadet
Joined
May 26, 2012
Messages
11
Re: Aftermarket RPM meter on my Mercruiser

achris said:
Mr Swordfish,

Welcome to iBoats....

You need to select '8 cyl', not 8 poles/cylinder... The number of pulses per revolution on an 8 cylinder 4 stoke engine is 4....

Does the new tacho have a brand name? (and model number... I will track it down for you if I can)

Chris...
Click to expand...

Hello Chris,

Thnx, later today I will look if I can find a number on the meter.
And alright 4 poles. Didnt know that.

Just a little question my engine runs fine at also at 8000 rpm (according to rpm meter) but thats just impossible for a mercruiser I guess?
 
achris

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Aftermarket RPM meter on my Mercruiser

Mr_swordfish said:
..Just a little question my engine runs fine at also at 8000 rpm (according to rpm meter) but thats just impossible for a mercruiser I guess?
Click to expand...

Yep....
 
Eric 3.7LX Alpha 1

Eric 3.7LX Alpha 1

Captain
Joined
Mar 27, 2010
Messages
3,028
Re: Aftermarket RPM meter on my Mercruiser

I'm thinking a stock engine would puke it's guts cruising at 8K. The gauge can't be set right.
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Aftermarket RPM meter on my Mercruiser

You have an outboard tach, not an IO tach. Get the right kind of tach and it will work.
 
M

Mr_swordfish

Cadet
Joined
May 26, 2012
Messages
11
Re: Aftermarket RPM meter on my Mercruiser

Hello,

Its indeed the same meter from the same company the only difference is that the plastic casing is blue.

So it isnt possible to set this meter to my mercruiser? Becouse as Chris stated about the 4poles if I set this meter at 4 poles its doing 7000+ at idle.
Only at 10 or 12 pole it dos an aprox correct reading.

Regards,
Martijn
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,459
Re: Aftermarket RPM meter on my Mercruiser

Mr_swordfish said:
Hello,

Its indeed the same meter from the same company the only difference is that the plastic casing is blue.

So it isnt possible to set this meter to my mercruiser? Becouse as Chris stated about the 4poles if I set this meter at 4 poles its doing 7000+ at idle.
Only at 10 or 12 pole it dos an aprox correct reading.

Regards,
Martijn
Click to expand...

Ayuh,.... Whatever ya do,... It's gotta read 700 rpms at Idle, 'n 'bout 4800 rpms at Wot....

Btw,... Mercruiser, 'n Mercury Marine are pretty much the same company,... I/Os, 'n Outboards...

Quiksilver is aftermarket for Both of 'em...
 
M

Mr_swordfish

Cadet
Joined
May 26, 2012
Messages
11
Re: Aftermarket RPM meter on my Mercruiser

Bond-o said:
Ayuh,.... Whatever ya do,... It's gotta read 700 rpms at Idle, 'n 'bout 4800 rpms at Wot....

Btw,... Mercruiser, 'n Mercury Marine are pretty much the same company,... I/Os, 'n Outboards...

Quiksilver is aftermarket for Both of 'em...
Click to expand...

Sorry, ofcourse not the same meter haha! Almost the same!
Well I will order a new meter. Going to look for an cheap one!

Thnx all!
 
achris

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Aftermarket RPM meter on my Mercruiser

Mr_swordfish said:
Hello,

Its indeed the same meter from the same company the only difference is that the plastic casing is blue.

So it isnt possible to set this meter to my mercruiser? Becouse as Chris stated about the 4poles if I set this meter at 4 poles its doing 7000+ at idle.
Only at 10 or 12 pole it dos an aprox correct reading.

Regards,
Martijn
Click to expand...

That's not what I said.... I said that an 8 cylinder 4 stroke engine generated 4 pulses per revolution.... VERY big difference....

If the tacho is Quicksliver then it will have come with an instruction sheet. On that instruction sheet it tells you the correct setting for the various engines. From memory (and it's along time ago that I last looked at one of those tachos) 1 is for 4 cylinder, 2 is for 6 cylinder, 3 is for 8 cylinder and 4 is for 12 pole alternator (outboards).... But read the instruction sheet....

Chris.....
 
M

Mr_swordfish

Cadet
Joined
May 26, 2012
Messages
11
Re: Aftermarket RPM meter on my Mercruiser

foto (1).JPG

I made an pic from the back of the meter. It almost says the same what Chris says. (the setings)
If set at possition 3 the RPM's can rise to 8000.

Chris sorry I misstated your words!
 
You must log in or register to reply here.
Top