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intermittent rough running 60hp '97 Evinrude

T

timmckenna

New member
Running at 'no wake speed' engine sounded good for 9 seconds then rough and throaty for 12 seconds for the entire 10 minute ride to the boat ramp. Varying speed slightly didn't change the pattern. First time in for the season was the day before and it ran fine on a little trip to the beach. On the return trip it wouldn't accelerate so I eased back and limped home at low speed hoping that I wasn't starving a cylinder and scorching it. Now it is back in my driveway.

The engine is a '97 60hp (E60TLUEA) 3 cylinder carbed with vro2.

The bulb wasn't real hard; pumping it up didn't change things. The gas tanks were clean and dry with new fuel. None of the system check lights came on though they cycle on for the self test. I can't be totally sure that the oil level went down since I only ran 2-3 gallon of gas. I had oil in the first 6gal tank but switched to the pure gas tank when it started acting up; no difference.

Got this engine last year, about 15 hours ago. Changed the fuel filter and rebuilt the carbs back then before I even used it.Ran a 'storage mixture' in for 15 minutes at the end of the season.

So far...
-plugs look similar to each other
-compression is 140, 140,140

what should I try next?
-replace the fuel filter?
-clean the carbs?
-change the gas line from the tanks to the engine?
-??
 
Bad fuel pump....my guess. Pump primer bulb when it does this, you will be acting like a manual fuel pump. See what happens.
 
Yes I read that, after reading the whole post a second time. But you also said the primer bulb never got firm. So, maybe the primer bulb has a bad check valve in it.
If so, pumping it to fill the carbs while at WOT would not work.
First, you must get that primer bulb to firm up. If you have a fuel leak, or if you have a bad primer bulb, it will not get firm.
 
It is firm but not rock hard. When the carbs are disconnected and I squeeze the bulb gas flows evenly out all 3 lines. I have tried my other line and tank too. I think Ill ask Jeff at Diamond Marine to let me use one of his and test it again
 
Well To me it sounds like it is running out of gas...then gets a bit and halfway picks up, then dies back...then gets a bit more....

Not being there....probably wrong....but.

Take the cowl off, and with engine off, just operate controls and watch very carefully the linkages as they move. Look under the flywheel, on the right side, and watch to make sure the timerbase is moving to it's full travel and back without sticking....

All this is free inspection...so do it. Just to be sure.

For that matter, try to run it with the cowl off to see if it makes a difference. If it has an exhaust leak into the cowling it can bog it down like that.

If that stuff doesn't help....you will have to go thru the full diag procedures.
Compression test. Report numbers if different from above.
Spark test with proper spark test tool.
Fuel delivery. You said the bulb freely pumps gas when fuel lines are open....that's good.

I guess another thing you can look at is when it is bogging like that, shut the key off and drift. Remove cowl, then locate carb drain screws.
Pull a carb drain screw, catch whatever comes out, examine for water, and make sure the volume that comes out seems to be a full bowl worth,
or if it was actually empty.....

Thinking again.....it could be water in the gas. I know what you posted....but could be water.
 
I like the idea to shutoff and check the bowels. I will try that on Tuesday. The linkage looks like iot is advancing and returning as it should. The Evinrude tech said it looked good.
 
Turns out it was the fuel pump. When Jeff (of Diamond Marine) watched the video it pushed him back to thinking it was a fuel problem; the slow repetition of surging and dying out did not seem to be electrical to him. When he took it out, he too pumped up the bulb when it was dying and it had no effect; so the common wisdom that if pumping the bulb has no effect, you can rule out the fuel pump turns out not to be true for these VRO2 type pumps. My mistake was to only check the choke at low speed. I though I was verifying that it wasn't stuck on but Jeff choked it at full-speed-dying-out and it came back to life. That was enough for him to decide it was the fuel pump.


So I spent the afternoon fishing in beautiful Ipswich MA, $1,200 poorer and with 4 weeks of summer having slipped away. $368 of it was Jeff repeating what I'd already done, plugs, fuel filter, rebuild carbs, change out the tank and hose. You see this kind of 'professionalism' all over our culture, from medicine to mechanics. The next $832 was 3 hours of labor + the VRO2 pump marked up 25% over what you can get it for from marineengine.com. I don't think they got rich off this job, between 2 trips to put it in the water, they probably spent more than 6 person hours.

So I learned a couple of things about diagnosing. Turns out there was no magic bullet of high speed tank or fancy test equipment. The two likely scenarios that I didn't want to get wrong were power pack or VRO2 pump. I could have bought both of those high price items + a coil, carb kits tank, hose and filter for less than 1/2 of what I spent at the certified tech. I shouldn't have chickened out, I was afraid to be just an (expensive) part replacer. Oh well. Thanks for all your help. Happy boating.
 
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