Evenrude 70 won't speed up lack of power.

[a937539]

Good morning.

What I have: 1700 17ft Lowe v 1993 with a 1993 70hp Evenrude VE70TLETS
The issue I'm having: lack of power, low rpm, hard to plane a bit of surging when back off full throttle. Slow 20mph
Pushing the key in primer seems to help speed up to 30mph. It ran better at full throttle last year would do 35mph with full live well and two people. But wouldn't idle, just die after a few seconds.
To fix the idle I installed new plugs, champion. rebuilt the carburetor per manual, replaced small fuel lines to carb and new fuel filter. That's when the issue started.
What I have done so far:
Got omc service manual
Cleaned carbs per manual again
Linked all carbs and adjusted idle and wide open throttle, throttle plates closed at idle and horizontal and full throttle
Replaced vro with diaphragm pump and flushed Fuel lines, pre-mix
Stainless hose clamps on large fuel lines
Spark test all 3 jump large gap 1/2in or so
Compression test 132-133 130
Drop test removing the spark leads to a noticeable sound change after removing each one
Installed a rpm gauge
New primer bulb. Clear line after primer bulb.
Tested on portable fuel tank and still have issues.


I haven't messed with the timing, I'm trying to track down a timing light.
I'm going to check the fuel pickup and anti-syphon valve next.
I'm familiar with carb work on trimmers and small engines.

Any help would be really appreciated. I have looked through a lot of forums in here and other sites and they have been a great help narrowing things down
Thank you

 

[Ronniewhite]

How hot is it getting? When did you change your impeller last?

 

[jimmbo]

Is the timing advancing as Throttle is applied?

 

[a937539]

How hot is it getting? When did you change your impeller last?

I don't know, and I haven't changed it since I got it. The gauge reads 6 psi at idle and 20-25 revved up. It has a good stream of water.
I have ordered an impeller kit and new thermostat and plan to install it this weekend. As well as move the tell tail to the top of the block as per the service bulletin. The alarm has never gone off. The alarm does beep when the key is turned on.

I'm not trying to throw parts at it, honest!

 

[a937539]

Is the timing advancing as Throttle is applied?

I seem to think it was. I'll check it and make sure it's rotating all the way to the stops.
Thank you

 

[racerone]

Timing does not normally go out of adjustment.-----But check for a sheared flywheel key !----And check for a cylinder sleeve rotated out of position.----You did remove high speed jet ( orifice plug ) from carburetor bowl to clean it ?----Nozzle gaskets in place in carburetors ?

 

[a937539]

Timing does not normally go out of adjustment.-----But check for a sheared flywheel key !----And check for a cylinder sleeve rotated out of position.----You did remove high speed jet ( orifice plug ) from carburetor bowl to clean it ?----Nozzle gaskets in place in carburetors ?

I'll check for a sheared key.

As for a cylinder sleeve rotating I put a borescope in the cylinders to check for damage. I didn't notice a cylinder rotating out of alignment with the exhaust and intake ports. I have the video of anyone wants to take a look. I don't know that I would recognize that's what it was if I saw it.

I removed the high speed from two of the carburetors. The 3rd was stubborn and I was afraid I would damage the brass but I was able to see a wire go through when cleaning it. Using a flashlight it looked clear with no obstruction

Nozzle gasket? Is that the flat gasket that goes between the pickup and the carb body that's in the center of the float? Number 18 in the parts diagram, yes they were in place.

 

[a937539]

Is the timing advancing as Throttle is applied?

The timing is advancing and the base doesn't seem loose, however the plastic link seems stiff.
The parts diagram calls it a dwell link is that supposed to move or slide back and forth when the throttle is applied? The plastic part with the spring.

 

[a937539]

I figured it out, the middle carb wasn't getting enough fuel. I forgot to install the center gasket in the carburetor bowl, emulsion tube gasket?

 

[jimmbo]

I figured it out, the middle carb wasn't getting enough fuel. I forgot to install the center gasket in the carburetor bowl, emulsion tube gasket?

Not good, as running with one Lean Carb, can certainly shorten the Lifespan of an Engine

 

[a937539]

Not good, as running with one Lean Carb, can certainly shorten the Lifespan of an Engine

Your right. I tried to make the trips as short as I could when trouble shooting.
Ill just have to keep an eye on it. I want to update to a 115-120 eventually.
It's running good now though.
Thanks everyone for your help.

 

[racerone]

Post #7 says they were in place.-----Now post #9 says you " forgot " one.