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Evenrude 175 HP 2 stroke

S

salmon hunter

New member
My outboard motor experienced reduced speed/ power for no apparent reason, then restored itself?
New motor to me, I just ordered the service manual.
Third time out, ran it up the lake 3-4k rpm, then trolling at 2-3 MPH for few hours, then half way back down the lake 3-4k rpm, motor slowed down the about 7 mph.... about ten minutes later it was able to return to the previous high speed...?
My first "guess" is the VRO pump?
Any thoughts, and/or what should I be checking thank- you for any insight
Marco
 
Please post your model # to help guide the discussion. The fuel pump is a possibility, but not the only potential culprit. You could have a spark issue, fuel restriction, dirty carb, overheat, fouled plugs, or who knows what else.
1) What is your compression?
2) Will the spark on each plug lead jump a 3/8" gap?
3) Did the primer bulb suck flat?
4) Did you get any warning horns or lights?

Your engine should be able to turn 5,500 RPM at wide open throttle. If you can't achieve that you're either over-propped or you have some other problem with the engine. when I buy a used engine I always install a new water pump and spark plugs just to be certain basic maintenance is done. Since you were trolling for a few hours, it's entire possible the plugs were fouled and they finally cleaned up and allowed the engine to run better.
 
kevinj said:
Please post your model # to help guide the discussion. The fuel pump is a possibility, but not the only potential culprit. You could have a spark issue, fuel restriction, dirty carb, overheat, fouled plugs, or who knows what else.
1) What is your compression?
2) Will the spark on each plug lead jump a 3/8" gap?
3) Did the primer bulb suck flat?
4) Did you get any warning horns or lights?

Your engine should be able to turn 5,500 RPM at wide open throttle. If you can't achieve that you're either over-propped or you have some other problem with the engine. when I buy a used engine I always install a new water pump and spark plugs just to be certain basic maintenance is done. Since you were trolling for a few hours, it's entire possible the plugs were fouled and they finally cleaned up and allowed the engine to run better.
Click to expand...
Thanks for some commen sense response.
Model number J175PXSNF
I will check compression
I didn't take notice of you and primer bulb, ....wish I had, thanks!
No warning lights or horn
I've been keeping an eye on the water spray/stream from the motor, seems good.
RPM was close to 5k, I never like to run full open, I usually pull back just enough to stay on plane.
I only pulled one plug on each side, they looked new.
I'll post any findings here,
Thanks much again for things to check.
 
The S.L.O.W. system may have kicked in.-----VRO tested and working / in service or bypassed and mixing at 50:1 in the tank.
 
kevinj said:
Please post your model # to help guide the discussion. The fuel pump is a possibility, but not the only potential culprit. You could have a spark issue, fuel restriction, dirty carb, overheat, fouled plugs, or who knows what else.
1) What is your compression?
2) Will the spark on each plug lead jump a 3/8" gap?
3) Did the primer bulb suck flat?
4) Did you get any warning horns or lights?

Your engine should be able to turn 5,500 RPM at wide open throttle. If you can't achieve that you're either over-propped or you have some other problem with the engine. when I buy a used engine I always install a new water pump and spark plugs just to be certain basic maintenance is done. Since you were trolling for a few hours, it's entire possible the plugs were fouled and they finally cleaned up and allowed the engine to run better.
Click to expand...
Thanks for some commen sense response.
Model number J175PXSNF
I will check compression
I didn't take notice of you and primer bulb, ....wish I had, thanks!
No warning lights or horn
I've been keeping an eye on the water spray/stream from the motor, seems good.
RPM was close to 5k, I never like to run full open, I usually pull back just enough to stay on plane.
I only pulled one plug on each side, they looked new
I'll post any findings here,
Thanks much again for things to check.
racerone said:
The S.L.O.W. system may have kicked in.-----VRO tested and working / in service or bypassed and mixing at 50:1 in the tank.
Click to expand...
Thats sounds interesting,
Is that a self check? Or what would make the S.L.O.W. system kick in.. I'll not familiar
Thank you
 
salmon hunter said:
Ah.. possible, no warning lite...
Motor can from salt water use.....

First time using this forum, very awesome, getting to learn this new motor. Very helpful.
Thanks
Click to expand...
Does your warning horn chirp when you turn the key to the ON position? If not, then your horn needs to be checked/replaced. Your scenario sounds like SLOW kicked in as Racer suggested. If this happened due to a hot condition you should have heard a warning horn. Does your boat have a tach with System Check lights or a dedicated 2" System Check gauge? If you do, and they are properly connected, you should have seen the HOT light illuminated if an overheat occurred.

Salt water motor? Okay, that helps a lot. Without knowing the full history of this engine, I would encourage you to replace the Water Pump and the Thermostats (you'll need 2). This is just good practice when acquiring a used motor, especially one that has salt water exposure.

Also, confirm that you have Champion QL78YC Spark Plugs installed. The ignition system in these motors do not like to run well with any other plug. You will have a lot of stores/people tell you there is an NGK plug that cross matches, but that is not entirely correct. Only use the QL78YC plugs.
 
kevinj said:
Does your warning horn chirp when you turn the key to the ON position? If not, then your horn needs to be checked/replaced. Your scenario sounds like SLOW kicked in as Racer suggested. If this happened due to a hot condition you should have heard a warning horn. Does your boat have a tach with System Check lights or a dedicated 2" System Check gauge? If you do, and they are properly connected, you should have seen the HOT light illuminated if an overheat occurred.

Salt water motor? Okay, that helps a lot. Without knowing the full history of this engine, I would encourage you to replace the Water Pump and the Thermostats (you'll need 2). This is just good practice when acquiring a used motor, especially one that has salt water exposure.

Also, confirm that you have Champion QL78YC Spark Plugs installed. The ignition system in these motors do not like to run well with any other plug. You will have a lot of stores/people tell you there is an NGK plug that cross matches, but that is not entirely correct. Only use the QL78YC plugs.
Click to expand...
Thank you sir, this info helps a lot! I actually have a new water pump kit coming....the red lite, about three of them blink on and beep accrues when key is on, (not sure if it always works).... I'll pay more attention to that.
I'll check the plugs, doing the compression check, perhaps today. and I'll look into changing thermostat, (two of them)
Thanks much
 
salmon hunter said:
Thank you sir, this info helps a lot! I actually have a new water pump kit coming....the red lite, about three of them blink on and beep accrues when key is on, (not sure if it always works).... I'll pay more attention to that.
I'll check the plugs, doing the compression check, perhaps today. and I'll look into changing thermostat, (two of them)
Thanks much
Click to expand...
Hello, everything is coming apart nicely, I have two new thermostats coming tomorrow, plugs are correct and look good, haven't fouled....
Water pump kit coming tomorrow as well.... here's the rub...
I Haven't Been Able To Find The Linkage To Discuss Connect, ?Model number J175PXSNF
I have the service manual coming, but not here yet 😕
I've taken the lower cowl off, ??
Thought's
 
salmon hunter said:
Hello, everything is coming apart nicely, I have two new thermostats coming tomorrow, plugs are correct and look good, haven't fouled....
Water pump kit coming tomorrow as well.... here's the rub...
I Haven't Been Able To Find The Linkage To Discuss Connect, ?Model number J175PXSNF
I have the service manual coming, but not here yet 😕
I've taken the lower cowl off, ??
Thought's
Click to expand...
The linkage I am referring to is to lower unit...
Also, left one bolt in, but loose enough so the lower unit dropped an inch and shifter is now in forward,
 
salmon hunter said:
The linkage I am referring to is to lower unit...
Also, left one bolt in, but loose enough so the lower unit dropped an inch and shifter is now in forward,
Click to expand...
I was able to find the correct cotter pin to release the shift rod,
Impeller was stuck to the shaft, lot's of clumpy oil around the water tube,
Cleaned it all up, new water pump kit coming today.
 
salmon hunter said:
I was able to find the correct cotter pin to release the shift rod,
Impeller was stuck to the shaft, lot's of clumpy oil around the water tube,
Cleaned it all up, new water pump kit coming today.
Click to expand...
Okay, so we got the LU removed. Be careful not to thread the shift rod in or out from it's original position. The height of the shift rod (measured from the LU mating surface) is a very specific measurement and is necessary to be exactly correct for proper gear shifting.
 
kevinj said:
Okay, so we got the LU removed. Be careful not to thread the shift rod in or out from it's original position. The height of the shift rod (measured from the LU mating surface) is a very specific measurement and is necessary to be exactly correct for proper gear shifting.
Click to expand...
Great,
I was able to put all back together, plugs were fine, changed both thermostats, (little holes were partially plugged, compression check all at 85-90, (that's where they stopped, higher on cranking),
Took her out trolling a little, running up past 4k RPM, working fine for a 2002 Evenrude 2 stroke six cylinder, with six carburators.
Thank you again for all the information given from everyone.
Information can be passed along!

Not going to touch the carburetors, but that will be my next learning curve, at 70 years old here, retirement learning years, hahaha, lol...!
 
salmon hunter said:
Not going to touch the carburetors, but that will be my next learning curve, at 70 years old here, retirement learning years, hahaha, lol...!
Click to expand...
These carburetors are not difficult. A common issue is the plastic fuel chambers on the carbs will warp and cause leaks. If you find them warped, don't try to sand and flatten then, just get replacements and go forward. The high speed orifice is screwed into the carb bowl, so be sure to remove that and transfer to the new bowl. Also, the pressed in BB's on the side of the bowls tend to cause a slight fuel seepage over time. A little JB Weld applied the BB's on the new bowls helps to avoid that issue down the road. Finally, when working on the carbs you'll also want to replace the O-rings on the fuel manifolds as they tend to harden and shrink over time.

KJ
 
kevinj said:
These carburetors are not difficult. A common issue is the plastic fuel chambers on the carbs will warp and cause leaks. If you find them warped, don't try to sand and flatten then, just get replacements and go forward. The high speed orifice is screwed into the carb bowl, so be sure to remove that and transfer to the new bowl. Also, the pressed in BB's on the side of the bowls tend to cause a slight fuel seepage over time. A little JB Weld applied the BB's on the new bowls helps to avoid that issue down the road. Finally, when working on the carbs you'll also want to replace the O-rings on the fuel manifolds as they tend to harden and shrink over time.

KJ
Click to expand...
Cool stuff,
I do have some small amounts of leakage, which I have read is somewhat normal...haha
I believe this will be a good storage time project this winter.... unless it gets worse..
I imagine the leakage would cause some performance issues..?
Thank you
 
salmon hunter said:
Cool stuff,
I do have some small amounts of leakage, which I have read is somewhat normal...haha
I believe this will be a good storage time project this winter.... unless it gets worse..
I imagine the leakage would cause some performance issues..?
Thank you
Click to expand...
Yes, the leakage can cause performance issues.
 
Another issue on starting my Model number J175PXSNF outboard.
I have to pump the primer ball 15-20 times, push key choke in, try about 3-4 times before it starts.??
It will restart just fine, no key choke, after fishing for a while with kicker motor.
Primer ball never really gets too hard, which I think is ok, I do feel gas pulling through.
Ball is pitching away from motor, which I think is wrong?
So antiphon in ball or on top of gas tank not working........or something else in the engine?
Carburators really not too leaky at all...
But if it's not in the antiphon, then I should carburator kit all six carburators??
Thanks
 
salmon hunter said:
I have to pump the primer ball 15-20 times, push key choke in, try about 3-4 times before it starts.??
Click to expand...
That's a lot of priming. Either the check valve in your primer bulb is bad or you have a leak somewhere.
salmon hunter said:
Primer ball never really gets too hard, which I think is ok, I do feel gas pulling through.
Click to expand...
The ball should get firm.
salmon hunter said:
Ball is pitching away from motor, which I think is wrong?
Click to expand...
There is an arrow on the primer ball that should point toward the engine.
salmon hunter said:
Carburators really not too leaky at all...
Click to expand...
The carbs should not be "leaky". If you have fuel weeping out anywhere on the carbs then you have issues that need addressed.
salmon hunter said:
..... then I should carburator kit all six carburators??
Click to expand...
These carbs are 22 years old. If they've never been serviced, then yes you should get new kits for all 6 and rebuild them. Since the plastic float chambers tend to warp you'll want to check those and plan on replacing them as well.
 
Thanks, great info
You mentioned previously to use epoxy, JP Weld ,on the BB's, sides of the bowls? Sounds extreme? Probably just a dab....
I will be getting to carb kits with bowls.
Primer ball as well.
 
salmon hunter said:
You mentioned previously to use epoxy, JP Weld ,on the BB's, sides of the bowls? Sounds extreme? Probably just a dab....
Click to expand...
Yes, just a dab. The BB on the side of the chamber is from drilling after the plastic bowls are cast. Over time the plastic shrinks and the BB loosens a bit allowing seepage/leaks. A dab of epoxy seals in the BB and prevents this from happening in the future.
 
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