Compression Test results on a 175xp Evinrude V6

[tmyers921]

Heys guys,
I did a compression test on my 1988 175xp V6 Evinrude. IS THIS OK?? Seems low to me???

Cold Test
1-90psi 4-90psi
2-90psi 5-95psi
3-92psi 6-92psi

Hot Test
1-89psi 4-90psi
2-90psi 5-94psi
3-90psi 6-90psi

SPARK TEST
Fine on all Cyl.

On Sunday I was running at about 30mph on the lake and all of a sudden
I lost about 50% of Power. I was able to get back to the boat ramp at slow speed.

It starts right up and throttles up fine in a tub of water.

Any thoughts on this?

Very Weird!

 

[mikesea]

Re: Compression Test results on a 175xp Evinrude V6

comp.and spark are fine.Did you try squeezing the ball or choking?It almost sounds like you had a bank go out,often if a pack fails you will lose that bank,you might have a loose connection to a pack ,or bad ground to a pack,there is one on each side of block with connections to your coils,.There is the possibility that you had a carb get some trash causing a couple cyl.to go out.If you run the engine,pull the plug wires off one at a time and put back ,note if you DONT get a performance differance,if you have a dead cyl,and it has spark anndcomp the prob is fuel ,especially if the opposite cyl is also out ,that would indicate carb,that said,you could also have a tank problem,especially a venting prob,usually happens after aperiod of time running when the engine cant pull fuel because vent is dirty or not performing,a quick test is,when it happens ,open cap to vent

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

You know,,,,,about a week or so ago, I was cleaning my bilge out. I thought I would start the engine and let it run for a bit.

When I went to pump the ball, it would not get hard. I was thinking vent then. I loosen the gas cap and it did get hard after that and I was able to start the engine.

I will check that out. Thanks for the reply!!!

 

[tashasdaddy]

Re: Compression Test results on a 175xp Evinrude V6

those are low compression engines. you are fine in that department. could have ran hot and went into SLOW mod.

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

I know when it did it, it started shaking real bad like it was going to fall off the boat.

As I said I slowed it down and she brought me back to the ramp (1 mile away),,,idled fine while loading on the trailer. Just weird. I'm alittle scared to take it out until I know what that was that caused it to do this.

Thanks for all your input guys, it gives me somethong to go on.

 

[Fishin76]

Re: Compression Test results on a 175xp Evinrude V6

If it started shaking real bad, You lost fire in at least one cylinder, if not a bank, as mentioned before. Check your coils. You may have a crack in one and it is ok until it gets warm. See if you can duplicate the problem on the water. When it happens, shut the engine off, pull one plug wire at a time and see what cylinders have NO effect on the engine. If it won't start back up, you may have found a good cylinder on the first try. If you feel idle or running speed change, that cylinder is OK. Once you find one bad, leave it off and find another, You may pull another and the motor dies, np, reconect and restart.

Some people say to take an inductive timing light with you, and test each plug wire while running at speed. Easy with two people, not so with one. The above can be done by one person.

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

Thanks for the info........ Its driving me crazy!

 

[Gary H NC]

Re: Compression Test results on a 175xp Evinrude V6

Sounds ignition related to me too.
If it was shaking that bad it was not firing on one bank is my guess.
The power packs would be suspect.

Good troubleshooting info her,
http://www.ebasicpower.com/downloads/cditech/CDI-Troubleshooting_Guide-JOHNSON-EVINRUDE.pdf

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

Thanks,
I was just thinking,,I may just go ahead and buy new coils. It may need them anyway.

You guys are really helping alott.

Thanks

 

[jonesg]

Re: Compression Test results on a 175xp Evinrude V6

S.L.O.W mode kicks in due to overheat or fuel restriction but an alarm shoulda sounded. Does it beep once when the key is turned on?

Unplug the temp sensor wire(brown) and with ignition on ground it to the head, if the buzzer sounds plug it back in again.

That leaves the fuel delivery. Make sure the primer bulb is pointing the right way, vent is clear etc. No excessive external filters, the right size fuel tubing.
Check the tank pickup screen for crud.

And fix the buzzer system, it can save your engine.

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

I didn't hear ant alarms at all.

I had a Force motor before this one.

The tech who swapped my motors bypassed the VRO pump. I mix my own fuel/oil 50-1.

I do have a water fuel filter in the line.

 

[emdsapmgr]

Re: Compression Test results on a 175xp Evinrude V6

Check your ignition first. As was mentioned, you may be dropping at least one cyl. You can try swapping the coils between cylinders to test them. While possible, it's unlikely the coils. They have a fairly low failure rate. I'd hate to see you replace them if all they are not the root cause of the problem.

 

[rodbolt]

Re: Compression Test results on a 175xp Evinrude V6

that shaking is the key, when the temp switch closes the pack gets the ground signal and missfires the ign and limits RPM to 2500 max and it shakes severly.
doesnt matter if the horn works or is even installed.
check water pump,thermostats,pressure control systems and the alarm horn for proper operation.
check alarm horn first, the engine will try to protect itself even if the horn is inoperative.
no RPM limiting for any other alarms.

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

I noticed the "pee hole" is still shooting water out. The engine dosnt feel or smell or even look like its getting out hot.

I'm a little confused about where to start next. I live 2 hours from any water way where I can put the boat in to work on it in the water. I have a huge tub that I use to start the engine and let it run for fresh water wash out.

I need to get a manual that is easy to read with step by step instructions.

One more thing I will mention,,,,,,,,,I need to replace the prop. Its a 14.25 X 21 and on my last outing, I was in a river that had no "Warning Markers" for low water. I was it 15ft of water and just barely got into 2.5 ft for a breif moment. Anyway, there was no difference in the running of the motor but when I put it on the trailer, I seen where the prop was chewed up a bit. It was a Sand bottom. I also check the pee hole and it was clear.

THanks for all the info guys,,,you are really helping me understand this. I just need step by step instruction as I said before. I'm pretty good at following directions.

 

[mikesea]

Re: Compression Test results on a 175xp Evinrude V6

You might have plugged a thermostat ,that overheating ,the the S.L.O,W. mode .Check the thermostats ,remove ,do a visual for dirt etc.then get a pot of hot boiling and cold water put them in one then other a notice operation,any question of trouble replace.Dont run to replace all your coils,it could be a pack,.thermo or heat sensor.You can also try disconnecting the heat sensors temp.and see if problem clears.They have a disconnect rthat can go on and off easl ,located top of head,

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

Thank you,,,I will try this and see what happens.

I still keep wondering what happen the day I went to start it and the Ball would not get hard until I loosened the Gas cap.

My gut is telling me to look there.

There is alott more stuff on this motor compared to that Force I had before.

WEW!!!

lol

 

[mikesea]

Re: Compression Test results on a 175xp Evinrude V6

Ive been thinking about your eng a bit.Ive been away from thebusiness a few yrs.but,I now think ,your problem is more fuel restriction,the heat sensors on your eng are the same,I believe the S.L.O.W. mode sensors .the port sensor was the SLOW mode sensor.So look at your vent for the tank,bugs loveto nest in there ,dirt buildup ,coroosion,if problem happens again.Open the cap,shut eng down to reset the alarm situation and run it .It could also be a bad vent hose ,but 99999 % of time the vent itself

 

[tmyers921]

Re: Compression Test results on a 175xp Evinrude V6

Will do,,,,
I will replace the vent hose all together. I know it needs to be done.

Thanks