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'1989 70hp Evinrude

B

bw94

Regular Contributor
I have a 70hp Evinrude, I'm having a hard time getting it started, and it's also idling rough, eventually dies. Compression is 130 on all 3 cylinders. Carb have been cleaned ( 3 times) and rebuilt. I replaced the VRO, with a standard fuel pump. Please, I need some help. Thanks
 
Re: '89 70hp Evinrude

Is this motor new to you and started fine in the past?

Is there a primer on it or choke plates?

I also have a 70 Evinrude that needs to be primmed for 6 seconds before cranking and has a long warm-up time, then runs great.
It is a monster to start in cold weather.
I have never used the oil pump. Always non-oxygenated fuel mixed 50:1

Is your inline fuel priming bulb staying hard?
 
Re: '89 70hp Evinrude

Proper starting procedure:

Pump fuel primer bulb up hard.
Apply slight bit of throttle to take throttle butterflies off dead idle position.
Turn key to START position, push & hold key in to activate fuel primer solenoid.
When engine fires and starts (normally within 6 revolutions), release key to ON position.

NOTE: Engine must turn over at least 300 rpms xin order for stator to energize powerpack. A slow cranking engine will not provide ignition.

(Fuel Primer Solenoid Function)
(J. Reeves)

The RED lever...... The normal operating/running position is to have that red lever positioned over top of the solenoid and aimed at the other end of the solenoid, gently turned to its stop. This is the normal/automatic mode position. Pushing the key in opens the valve within the solenoid allowing fuel to pass thru it in order to prime and start the engine. Looking upon this solenoid as a electric choke results in a better understanding of it.

Having that red lever turned in the opposite direction, facing away from the solenoid, allows fuel to flow thru it to the crankcase area. One would only turn the red lever to this position in a case where the battery might go dead and the engine had to be started via the rope pull method. Look upon putting the red lever in this position as moving a choke lever on a choke equipped engine to the full closed position. Either one would supply fuel to the crankcase/engine for starting purposes BUT if left in that position while running would flood the engine.

The later model primer solenoids are equipped with a schrader valve, used for attaching a pressurized can of fogging oil etc, available at your local dealership with complete instructions.

Pumping the fuel primer bulb up hard fills the carburetor float chambers of course, but that process also applies fuel pressure to the primer solenoid.
The two small hoses leading from the primer solenoid branch off via tees to each fuel manifold section that would feed fuel to the individual cylinders.
Pushing the key in activates the primer solenoid to allow fuel to flow thru it to the intake manifold passageways. Cranking the engine over causes the fuel pump to engage which in turn sends fuel pulses to the primer solenoid via the 3/8" fuel hose.
Some engines incorporates the "Fast Start" feature which automatically advances the spark electronically so no advance of the throttle is required for starting.
Engines that do not have the "Fast Start" feature will be required to have the throttle advanced slightly.
Starting procedure: pump fuel bulb up hard, crank engine and push the key in at the same time. When the engine fires/starts, release the key so that it falls back to the run position.
Bottom line..... Look upon the primer solenoid as an electric choke.
 
Re: '89 70hp Evinrude

Thanks Joe. Yes this boat is new to me, it sat up for about 6 years, the guy i got it from said it ran great. So far i've changed the impeller, cleaned and rebuilt the carbs, switched to a standard fuel pump, new gas tank and new gas lines. It has the primer solenoid, and a choke, i can push the key in to choke it. Once on the lake and the boat warms up it will run great wide open,but when i try to troll or idle it will die. I was told it might be my low speed jets, but i've soaked them in Chem-Dip for a week, and used small wires to clean all of the holes. The carbs are fixed, there is no high or low speed adjustment. Any Ideas?
 
Re: '89 70hp Evinrude

Remove spark plugs. Rig a tester whereas you can set a spark gap of 7/16". The spark must jump this 7/16" gap with a strong blue lightning like flame.... a real SNAP! Does it?

No Tester? See below.

(Spark Tester - Home Made)
(J. Reeves)

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
　
..........X1..........X2
.................X..(grd)
..........X3..........X4

If weak erratic spark is what you get, or no spark with that gap setting, look under the flywheel to inspect the stator (you may need to remove the flywheel). If the stator is cracked bad and/or dripping a sticky looking substance down upon the timer base and powerhead area, that would cause a voltage drop to the powerpack. Let us know what you find.
 
Re: '89 70hp Evinrude

You can buy a spark tester at most any auto supply store, I like the open air ones with adjustable spark gap. remember you want to buy one with 4 wire/gap so you can test all three of your wires at one time and not do harm to your ign system.
 
Re: '89 70hp Evinrude

Gbro said:
Is this motor new to you and started fine in the past?

Is there a primer on it or choke plates?

I also have a 70 Evinrude that needs to be primmed for 6 seconds before cranking and has a long warm-up time, then runs great.
It is a monster to start in cold weather.
I have never used the oil pump. Always non-oxygenated fuel mixed 50:1

Is your inline fuel priming bulb staying hard?
Click to expand...

I'm interested that you use a 50-1 mix, and not the oil injection. Do you have to do anything particular to accomplish this? Or do you just start running the 50-1 mix and that's it? I suppose you would then not need the oil tank and could remove that...?

Until I read joereeves instructions, I couldn't start my motor ('87 70hp). Using his instructions, it's perfect. Thanks Joe. Only got the boat & motor a few days ago, and the former owner didn't fill me in. Out again today...perfect again...no trouble at all.
 
Coco..... Glad to hear that my instructions were os use to you.

Haven't heard from BW94 since June of 2010. Wonder how he made out.
 
Joe...do you know anything about using the 50 - 1 mix instead of the oil injection? It makes no difference to me either way really, I suppose. Except it might be easier to use the mix.

The good Doctor who sold me the boat said he never quite trusted the oil injection, and apparently has always added a little 2 stroke oil to his gas anyway.

Thanks again for your very complete instructions, without them I think I might still be rowing!
 
The main thing is peace and ease of mind. The VRO setup appears to have been perfected, however a faulty VRO coupled with a failed warning horn (it happens) results in a blown powerhead. But evcen the warning horn has a self test now where it beeps when the key is turned on.

With the VRO, the oil flow is adjusted with the RPM setting. With pre-mix, the oil flow is constant. Tough decision.

(VRO Changeover Judgement Call)
(J. Reeves)

The VROs first came out in 1984 and have been upgraded quite a few times. In my opinion, back around 1988, they had perfected them but I think that they were upgraded even more since then. As long as the warning system is operating as it should, I feel quite at ease with them.

Some boaters have voiced their thoughts such as "What if that overpriced plastic horn should fail while I'm under way for some reason, and the VRO decides to fail five minutes later?" Obviously that would result in a big problem which really brings their fears into view.

The word "ease" is the key word though. If one has the slightest feeling of being ill at ease with that setup, then they should take the route they feel more at ease with. A judgement call each individual would need to make on their own.

********************
(VRO Pump Conversion To Straight Fuel Pump)
(J. Reeves)
You can convert the VRO pump into a straight fuel pump, eliminating the oil tank and VRO pump warning system, but retain the overheat warning setup (and fuel restriction warning if so equipped) by doing the following:

1 - Cut and plug the oil line at the engine so that the oil side of the VRO pump will not draw air into its system. Trace the wires from the back of the VRO to its rubber plug (electrical plug) and disconnect it.

2 - Trace the two wires from the oil tank to the engine, disconnect those two wires, then remove them and the oil tank.

3 - Mix the 50/1 oil in the proper amount with whatever quantity fuel you have. Disconnect the fuel line at the engine. Pump the fuel primer bulb until fuel exits that hose with the tint of whatever oil you used. Reconnect the fuel hose.

That's it. If you want to test the heat warning system to ease your mind, have the key in the on position, then ground out the tan heat sensor wire that you'll find protruding from the cylinder head. The warning horn should sound off.
 
Once again Joe, many thanks.

You have inadvertently answered two other queries I had. I didn't know why there was a beep when I turned the key on...and I had noticed a brown wire hanging down off the engine not seemingly connected to anything on the south end. So, two more questions resolved.

I think that since the good Doctor has always used the oil injection, along with a small amount of oil in the fuel tank, I see no reason to change that now. It appears to have functioned for the last 23 or 24 years quite well.
 
Joe, I have one other question which has just arisen.

I visited the dealer yesterday to buy plugs and high tension leads, and they need the model number off the motor.

This morning, I was able to get at the plate to see what it is, but it has been damaged so badly (a large deep cut and corrosion) that it is completely illegible. I tried taking several photos and blowing them up on the Mac, but no numbers show up at all.

Is there any other way to identify which model number it might be. I do not have the original owner's manual and doubt that it still exists.

Thank you again.
 
Look on the powerhead for a small quarter size core plug (looks like a small freeze out plug). It usually has the model and serial number imprinted upon it.

Use Champion QL77JC4 plugs. Gap them at either .040 (original recommendation), or .030 (later recommendation). One or the other may give improved performance either at idle or full throttle. Try both and compare.

Plug wires? I'd make my own..........

(Replacing Regular Spark Plug Wires)
(J. Reeves)
If you also need the spark plug boots and the spring terminals that connect to the spark plugs, purchase them from your local dealership (OMC Part #581027). This includes one boot and one spring connector. Price is about $3.25ea.

Purchase whatever amount of spark plug wire you need. Be sure to purchase the kind that has a steel twisted wire leading through the center of it....... not the carbon type plug wire that many automobiles now use.

Using your old plug wire, cut the new wire to a length about 3/4" to 1" longer. If you have no old plug wire, just make sure that the wire is longer than you'll need as you can trim the other end later.

The rubber boot, spark plug end.... With the wire cut to the length required, trim back 1/4" insulation again but do not solder tint the wires. Simply fan out the wires and fold them back against the insulation, cutting the excess off as explained above. Holding the spring wire terminal, estimate where the prong should be inserted so that the spring will be flush against the exposed wire. Hold the spring terminal away from the wires end (sideways) and insert the prong into the insulation and into the center wire, then swing the spring terminal in front of the exposed wire portion (makes a tight fit for continuity purposes).

Spraying the inner portion of the boot where the wire will insert with a small amount of WD40 makes the installation of the wire a easy project. That's it.... you're done.
 
Once again I am in your debt. Spent many years building race car engines, and I never did like the carbon wires.

Many thanks for your always concise and complete information.
 
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