Resolved 1985 mariner 175 powerloss on top end

[fisherman81654]

I ordered a new stator because I thought it was causing me too lose rpms on top end.
The stator I had was the older one that was black,which I have been told by a tech,that it could be the problem and if its not the problem,it wouldn't last long anyhow. at least now I don't have to worry about that and I did a dva test on the new stator and the older trigger and switchboxs,all in specs.

My problem is the boat used to run with lots of Power!,at 5500 rpms and it would go to 6ooo rpms.I f remember right about a year or so,I was running down the lake and the motor started missing ,like you were taking a spark plug off and on,then it stopped making that sound.I believe thats when the problem occured.
Now all I can get out of is 5200 rpms.
The bow used to trim way higher than I needed,now the bow is just lever.
I have good compression,120 on all six clinders.
New plug wires.primer bulb pumps up hard and stays hard,new fuel filter,rebuilt fuelpump two years ago,although after the run today on the lake I pulled all the plugs and they were all wet except the top one on starboard side, it was dry and the top one on port side was just a little wet,I don't have a fuel guage to test fuel pressure.Thought about taking the lines loose were they go onto the carbs and crank the engine and see what kind of stream I have .I have not tried this yet.Can a trigger be bad and dva test ok?I have decent fire on the plugs on all six clinders. Does the top carb feed the top two cylinders?,if so could the top carb have a problem feeding one of the top cylinders?

 

[Faztbullet]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Disconnect the idle stabilizer box if it is still equipped....

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

I already did that Faztbullet,Thanks....

 

[bigjack54]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

I have seen posts were thy say you can have a good test and a bad stator, but not a bad test and a good stator. Just saying don't know for shore though
ing

 

[Sprky]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Do the "carb cleaner test" It will tell you whether your problem is fuel, spark or other.

The stator creates the voltage and the boxes and trigger manage it. If your stator was bad you would loose one whole side not just one plug.

You are guessing and it is going to end up costing you a lot of money.

Perform the test and tell us what the engine did. ....... (It will pick up, fall down or do nothing) From that info, we determine which way to go.....Simple Simple

Call when you are on the ramp and I will walk you thru it.

Chris 512-264-3124

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Do the "carb cleaner test" It will tell you whether your problem is fuel, spark or other.

The stator creates the voltage and the boxes and trigger manage it. If your stator was bad you would loose one whole side not just one plug.

You are guessing and it is going to end up costing you a lot of money.

Perform the test and tell us what the engine did. ....... (It will pick up, fall down or do nothing) From that info, we determine which way to go.....Simple Simple

Call when you are on the ramp and I will walk you thru it.

Chris 512-264-3124

Heres the newest update on not being able to reach 6000 rpms.
I took the boat out today on the lake after rebuilding the carbs for the second time,blew something out of the main jet on second carb,went so fast I berly saw it,lol,anyway guess what,I reached 5900 rpms!! and then after running at that rpm level for maybe 20 seconds,I backed the throtle off and coasted to see how idle was.Idle was perfect.
Ok so I say ,lets do it again,NOPE.... RIGHT back to 5000 rpms,very discouraging.Total time running engine was maybe fifteen minutes.

This is what I have done to this motorserial# A137316)new plugs New plug wires, cleaned all coils and grounds,new waterpump,new gear oil in lower unit,new stator, new kits for crabs,new gaskets for reed blocks,inside and out.new fuel filter,rebuilt fuel pump,new hoses for fuel,new regulator.
Dva tested new stator ,old trigger, coils. with muffs on all had good spark at idle.

Before I went to the lake had the motor on muffs and sprayed some carb cleaner(just a little)in each carb ports,you could hear a difference in the engine each time.I guess later today I will try the same thing and see if I still have those good results.

Chris I appericate that.

 

[Sprky]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Now you are no longer guessing about your problem, it is fuel.

To find the offending cyl.............run the motor on the lake removing 1 plug wire at a time. Look for the cyl that makes no diff on performance when the wire is removed.

Remove cowls then put boat in the water.

Make a pass and note wot rpm's

Shut down and remove 1 plug wire

Make a pass and note performance.

Rinse and repeat until you find the cyl that runs the same plug wire on, plug wire off.

Look at the carb for that cyl..... You have to be thorough when you clean the carbs, as evidence by what you missed the first time.

The carb cleaner trick has to be done over 2500 with a load on the motor to find an occluded main, otherwise at idle the motor is running on a different circuit.

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Now you are no longer guessing about your problem, it is fuel.

To find the offending cyl.............run the motor on the lake removing 1 plug wire at a time. Look for the cyl that makes no diff on performance when the wire is removed.

Remove cowls then put boat in the water.

Make a pass and note wot rpm's

Shut down and remove 1 plug wire

Make a pass and note performance.

Rinse and repeat until you find the cyl that runs the same plug wire on, plug wire off.

Look at the carb for that cyl..... You have to be thorough when you clean the carbs, as evidence by what you missed the first time.

The carb cleaner trick has to be done over 2500 with a load on the motor to find an occluded main, otherwise at idle the motor is running on a different circuit.

Sounded like a good plan,but no luck.
Each plug wire I took off lost 500 rpms,in others words ,take a plug wire off and the boat run 4500 rpms at full throtle,happened each and every plug wire that I took off.
I don't know why but I suspect the trigger,even tho it check good with dva test,one of the tests berly made it in specs.I just hate to buy something for no reason,even tho that trigger is twenty six years old and for that matter so are the power packs or switchboxs. As far as hole slot,used to be,when I give it full throttle it would scream out of the hole,now it has just a little delay then kicks in,like like before.

I really don't know at this point.
Strange, it worked for a little while today ,then thee same problem,(ever what that is) lol

When I plane up at full throtle,The bow is just level.It used to go way to high,I suppose its cause I am going only 5000rps.
The jacks that raises the trim are firm,no bleed and the trim guage stays at the same place when I reach full trim height.

I need that extra power because when I fill my bait tank and live well ,well its really noticable,berly on plane then.

 

[Sprky]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

If each cyl drops the same, then the ignition is ok. Is the motor getting full advance on the timing? Make sure the timer base is moving to full advance. How much advance are you running?

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

If each cyl drops the same, then the ignition is ok. Is the motor getting full advance on the timing? Make sure the timer base is moving to full advance. How much advance are you running?

Timer base? Is that the trigger,like when you have full throtle,the trigger advances?
I looked at that earlier and the wires running to the trigger were getting stuck on top of the block, I saw that and thought uhuh, that why it wouldn't go back to 5900 rpms that I had run eariler today.I fixed that,took the boat back out and run it .I still could only get 5000 rpms.

I agree ,seems like I am not getting that advance in timming on hole slot and top end.
I need someone on the back of the boat,to look at it to see if I am getting the advance ,when in the hole and top end and if it is moving,Does that mean thats its actually working?

As far as setting the timming ,that is beyond me,I don't want to blow the motor.

I took it to a boat shop to have that done awhile back and all the screws are still tight.

 

[Sprky]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Is your idle ok or did it go away with your rpm's?

You are sure about all your stop screws being tight?

On your packs, how many wires coming off the bias circuit. There should be only one, a white with black tracer that connects the two packs.

When you replaced the stator, did you check the magnet on the center hub. I have seen them come loose and spin.

This would be easier via phone.

Call

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Is your idle ok or did it go away with your rpm's?

You are sure about all your stop screws being tight?

On your packs, how many wires coming off the bias circuit. There should be only one, a white with black tracer that connects the two packs.

When you replaced the stator, did you check the magnet on the center hub. I have seen them come loose and spin.

This would be easier via phone.

Call

Idle is fine ,all screws are tight ,have not moved,bias wire is hooked up.
Take a look at pic for flywheel.
A long time ago was going 55 mph on the lake heard a loud clang clang ,like metal grining for a second,shut it down and tore it down,could not find anything wrong.I have 120 compression on all cylinders.I replaced stator,couple days ago,took a close look at the stator,it had some scratchs on it and a small spect of metal embeded in it,wasnt bad but I wander where the damage came from.Do you think my flywheel looks fine?I see the center magnet,just dont know if it had more housing around it.

I will give you a call if the flywheel is ok.

Also here is a pic of the trigger.I dont think the tear in the housing is a problem but could be I guess.
It got damaged by the trigger moving,got caught on the engine block at one time apparently.
One more thought,after installing new stator and flywheel,would I have to set the timming again?The reason I ask is I noticed the old stator had what look to be timming marks on it.I position the new stator in the same holes on the block.
Thank you !

 

[gwukena]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Have you checked your upper crank bearing for play? Does the new stator show any signs of contact?

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Have you checked your upper crank bearing for play? Does the new stator show any signs of contact?[/QUOTE

The upper crank bearing has no play in it and no signs of rubbing on the new stator.

 

[Sprky]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Stator only developes AC voltage for the ignition and charging system. Placement has no affect. All the stators seem to have scuffing on them.

Call me.

 

[CharlieB]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

It is still possible that you have a broken, yet abutted wire, on a trigger. Intermittently failing as the timing advances.

Test to prove/disprove by removing all spark plugs (to reduce load on the starter and battery), pull the lanyard or ground all plug wires, disconnect the throttle cable.

While cranking and watching DVA output move timing lever from idle to full advance, SLOWLY, and wiggling the trigger wires. Test each trigger this way, any drop in trigger output is cause for suspicion.

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Sounds good CharlieB.
I am going to try one more thing before I proceed with that test.
I am going to run the boat on the lake at 3500 rpms and have someone squirt some fuel in each cylider,if thats the problem,then Iwill know which carb to dissassemble and soak it for a year lol.

It is still possible that you have a broken, yet abutted wire, on a trigger. Intermittently failing as the timing advances.

Test to prove/disprove by removing all spark plugs (to reduce load on the starter and battery), pull the lanyard or ground all plug wires, disconnect the throttle cable.

While cranking and watching DVA output move timing lever from idle to full advance, SLOWLY, and wiggling the trigger wires. Test each trigger this way, any drop in trigger output is cause for suspicion.

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

I performed the spray test in each port running motor on the lake at 52 rpms.
There was no change in the rpms.
To me,that tells me the motor is getting the right about of fuel and that the carburators are in fine shape.

It has to be a electrical problem,since I already replaced the stator and the coils checked out ok. It must be the trigger or the switchboxs.

I will looked deeper into that today.

 

[fisherman81654]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

http://www.boatpartstore.com/page20.asp My dva test on the trigger is good while the motor is running on muffs but when cranking with a fully charged battery,the test readings are low at brown/yellow to brown/white reading 2 volts.
When the motor is running, in the idle mode, it is dva 5 volts. The other wire tests were in specs.

 

[CharlieB]

Re: 1985 mariner 175 powerloss on top end

Re: 1985 mariner 175 powerloss on top end

Keep testing the triggers.

Whack the throttle and watch trigger output. CAREFUL, do not hold the throttle open, just whack it to see the voltage rise with RPM, repeat on each trigger.

Did you try moving the timer/throttle during the cranking tests to see if any change with wire position?

The trigger is beginning to look suspicious, but without solid evidence I still don't recommend replacement until a few more tests continue to show low readings.