1991 175hp Max RPM ??

[sportcraft17]

I have a 1991 175hp Evinrude with 35amp charging system, any idea what is the max rpm? And at idle is 900 rpm ok? I?ll appreciated any help
Thank you

 

[tashasdaddy]

Re: 1991 175hp Max RPM ??

rather see idle lower, 900 is rough on shifting. developes 175 hp at 5000 rpms. 5500 -6000 max. if you prop to 5500 wot, you will be good.

 

[Dhadley]

Re: 1991 175hp Max RPM ??

Which 91 175 do you have? We'll assume it's the crossflow. Right?

 

[sportcraft17]

Re: 1991 175hp Max RPM ??

Hi, not sure if it is a crossflow? Here is the model number: VE175TXEID, Long Shaft, also how do I know if I have the right rpm gauge? These gauges wore replace by the previous owner and he never tested them, I was on the water yesterday and the gauge was over 6000 rpm (max rpm Gauge is 6000) and the boat was just crusing at ? of throttle, 35 to 40 knots, I did give it more throttle to full throttle and at full throttle was doing about 55 knots, ( is a Dusky Boat 22 footer CC and the prop is a 19 pitch SS) but since gauge was over the limit I came back to cruise speed. The Motor since like it was on the right adjustments but the gauge was telling a different story.

Thanks

 

[Chris1956]

Re: 1991 175hp Max RPM ??

It sounds like your Tach is on the wrong setting. With a 19" pitch prop on that motor and that 22 footer, you may approach 6000 RPM, but likely not exceed it.

I do not remember what the setting is off hand, but there is a setting for the lower HP OMC motors and a setting for the higher HP motors, that you should be using.

 

[sportcraft17]

Re: 1991 175hp Max RPM ??

Any idea what type of Tach, it is used on these outboards? And any idea what is the setting at idle?

Thank you

 

[72SideWinderSS]

Re: 1991 175hp Max RPM ??

Most tach's have a setting on the back for number of pulses or poles, yours should be set for 6 pulses or 12 poles which ever is marked on the back.

Was your max speed of 55 truly knots or was it MPH ?

If it was knots then you should have been bumping your rev limiter (6875 rpm), if it was MPH then you should have been turning about 6384 rpms.

this is figuring a 10% slip rate.

 

[emdsapmgr]

Re: 1991 175hp Max RPM ??

Your model # indicates a 175 crossflow. A solid engine with lots of torque. Your engine is rated to run between 5250-5750. I would prop it to run in the 5750-5800 range. It should idle at 650 in gear.

 

[sportcraft17]

Re: 1991 175hp Max RPM ??

Hi, and thanks to all of you for your help, boat speed was on MPH, the Rpm gauge is a Gaffrig Gauge rpm x 1000 max 6000 rpm, there are no setting on the back, here is a link of a similar Gauge

http://www.tpmarine.com/index.asp?PageAction=VIEWPROD&ProdID=121

Is it time to replace the Tach and go from there? Or should I try something else?

Testing the boat today, the throttle cable broke, I have tried different places and they don?t carry this type of cable anymore. Even eBay doesn?t have a cable like this one. Do you guys know any other place that you guys may know where I can buy this cable. New or used either way it is fine. Cable is 22 foot long.
here is a picture

Thank you

 

[Gary H NC]

Re: 1991 175hp Max RPM ??

Any markings on the cable? looks like my Teleflex cable.
I think that Tach is not for an outboard...No little small switch on the back of it?

 

[Dhadley]

Re: 1991 175hp Max RPM ??

Looks like an old standard Morse cable for OMC's. You don't have to have a Morse (probably hard to find since they're basically gone), you can use a Teleflex or BRP Long Life cable. All the same from 1979 on. Iboats has them. Any Evin / John dealer will stock them.

Hard to tell on the tach but most 6000 rpm tachs are for 4 cycle. 2 stroke tachs are mostly 7000 tachs. Not always but most times. Once you get the tach straightened out I think you'll find the 19 is a bit optomistic.

 

[sportcraft17]

Re: 1991 175hp Max RPM ??

I just double check the Tach and there is no switch on the back, just wire connection, as for the cable, I have look at different brands of cables and they all have almost Identical connector the problem is how to hold in place the cable on the control box, that?s where all the cables are different from mine. On this new picture you can see how the cable it is hold in place.

Thank you

 

[sportcraft17]

Re: 1991 175hp Max RPM ??

Anybody!!!!