72 125hp

[72evinrude]

125esl 72r
After adjusting the timing at 5 deg btdc the rpm was 900. Tried it under load and results were the same. Should I adjust the low speed jets to accomplish 650/675 rpm?
Also can the low speed jets be soldered and redrilled?

Question (2) Can the cylinder heads be re-threaded using inserts?

Thanks,
72evinrude

 

[wilde1j]

Re: 72 125hp

Idle speed is not adjusted by the jets. I wouldn't solder and redrill! Idle RPM is almost always an external adjust screw or stop, is adjusted in the water in gear to ~ 650 to 700 RPM.

Stripped spark plug holes may be fixed using helicoils. If you've never done it, take the head to a machine shop, who will do it right and economically. A new head gasket, torquing the head bolts, etc. are required as well as part of the fix.

 

[emdsapmgr]

Re: 72 125hp

If it won't idle down at 5 degrees, retard it to 4 degrees. You don't want to change anything with the jets, as wilde indicated.

 

[72evinrude]

Re: 72 125hp

If it won't idle down at 5 degrees, retard it to 4 degrees. You don't want to change anything with the jets, as wilde indicated.

When I retard to get lower rpm the engine will run for a while and shut off like ignition off.

Also when checking the sensor gap I forgot the key was on and I recieved a shock. Should this happen? At low idle maybe a voltage leak is shorting it out!

 

[72evinrude]

Re: 72 125hp

Thanks wilde1j.
I have an ome service manual but it is very surface only. Not too much detail as far as I'm concerned.

 

[72evinrude]

Re: 72 125hp fuel and electrical problems

Re: 72 125hp fuel and electrical problems

carbs and passages cleaned, one new float seat/needle, floats parallel to bowl, one spark plug wire entered only into weather cup, .090 slop in rotor notch, flywheel too high letting rotor bounce, pulsepack ground very corroded, check sensor for grouding and ohms, ok.

The motor now idles smoothly at 650 rpm at 5 deg but just for 3-4 minutes. Took pump apart, diaphragm has no tears but looks very old. It does pump fuel but I am WOUNDERING if I have enough pulse pressure at 650 RPM to pump enough fuel. Thinking of trying an electric low pressure pump to see if there is improvement.
The pump is listed as non-serviceable. But I did find another pump and kit that looks just like it.

This forum is great and I thank all of the knowledgable people for the help.

72evinrude

 

[Daviet]

Re: 72 125hp fuel and electrical problems

Re: 72 125hp fuel and electrical problems

I wouldn't install an electric fuel pump in your motor, not safe. Is your 650 idle in gear or neutral? I beleave it should idle at about 900 in neutral and about 650 in gear.

 

[SparkieBoat]

Re: 72 125hp

is a low pressure fuel pump ok?? I have been running one on mine..so far ok and no fuel problems..I have another boat with a 100 evinrude and the fuel pump is not so strong..so I thought of adding one to it also..these are like 3-5 psi fuel pumps. I wouldnt think that it would be an unsafe fuel pressure..but I have been wrong before.
Sparkie

 

[SparkieBoat]

Re: 72 125hp

o yea and I placed the pump by the gas tank, which is under my center console.

 

[72evinrude]

Re: 72 125hp fuel and electrical problems

Re: 72 125hp fuel and electrical problems

I wouldn't install an electric fuel pump in your motor, not safe. Is your 650 idle in gear or neutral? I beleave it should idle at about 900 in neutral and about 650 in gear.

Daviet, Electric pump is for trouble shooting only.
In the drive way I can set 650 and it's smooth but runs only 3 minites,
in water 900 does go to 650 rpm and will run 2 minites. I have to choke to restart. If I throttle up right away the engine bogs. (low level in float bowls?)
The pump looks good but I'm concerned the pulse from the engine is too weak at low rpm.

 

[emdsapmgr]

Re: 72 125hp

Not sure it is a pump issue. If you think the pump is weak, constantly prime the hose bulb. This will force fuel around the pump into the carbs to keep them full. If it runs ok while you constantly prime the bulb, you may have a weak pump. When these pumps begin to fail, they are usually ok at idle, but fail to deliver the volume needed to run max rpm's.

 

[72evinrude]

Re: 72 125hp

Not sure it is a pump issue. If you think the pump is weak, constantly prime the hose bulb. This will force fuel around the pump into the carbs to keep them full. If it runs ok while you constantly prime the bulb, you may have a weak pump. When these pumps begin to fail, they are usually ok at idle, but fail to deliver the volume needed to run max rpm's.

I'm concerned the pulse from the engine is too weak at low rpm.
Is it one cylinder or all that cause this pulse?

 

[wilde1j]

Re: 72 125hp

Pulses caused by all cylinders. Sounds like it's running long enough to empty float bowl, then stop. i.e. pump not pumping. What's it do if you squeeze the primer bulb every 20 to 30 seconds? Keep running?

You may have any of a number of things causing this, other than the pump itself, such as air leak into suction side of pump at any fitting/clamp, cracked pickup tube in tank, blocked pickup tube screen, tank not vented properly, etc. OR a bad fuel pump. Very unlikely pulses are an issue here.

 

[72evinrude]

Re: 72 125hp

Pulses caused by all cylinders. Sounds like it's running long enough to empty float bowl, then stop. i.e. pump not pumping. What's it do if you squeeze the primer bulb every 20 to 30 seconds? Keep running?

You may have any of a number of things causing this, other than the pump itself, such as air leak into suction side of pump at any fitting/clamp, cracked pickup tube in tank, blocked pickup tube screen, tank not vented properly, etc. OR a bad fuel pump. Very unlikely pulses are an issue here.

I have tried the bulb and it is hard. I will try removing the bowl line to make sure I can bypass the pump this way. The way it is built (2 reeds in and out)
it should bypass the fuel. WOT is good.

Also tried manual choking and no help.

Last time "IT" quit so did I. Next day I removed the bowl drains and fuel leaked out. Now I'm confused again on the fuel thoughts. Could residual tank pressure refill them over night?

 

[wilde1j]

Re: 72 125hp

Tank should have zero pressure and be vented.