Problems with 86 Evinrude 70hp

This is my second season owning my boat, last season it had some issues, but i just dealt with them, now I just want to get it running smoothly. Some details, the motor is still running the VRO pump, I have only had the boat 2 years and the previous owner did not keep very good records, but the pump had a tag on it that said "Ethanol safe" or something like that. does that mean it is a newer pump? im assuming ethanol wasnt an issue in '86. I was running champion plugs until yesterday, i switched to the NGK BZ7HS-10's. Compression is 115ish on all 3cyl (is that good?). I recently went through whole fuel and oil system and tightened and retightened all hose clamps to make sure there were not air leaks. I did a de-carb on the motor today and took it to the water today to test it out. Motor seems to run smoother but im still haveing the same major issue. The motor will idle great, and runs at WOT great(runs about 33mph on a 16' sportcraft). but at trolling speed it will run for maybe 10 seconds then sputter and stall out. If i can get it back out of gear in time it will idle back up fine. When it cuts off, its difficult to start back up and smokes alot when it does start. I have noticed when i take the hood off the carbs that there seems to be more fuel sitting in the carb than there should be at idle. But then again I dont know how much there should be, if any. I put a new primer bulb on it today, pumps up good and hard, and softens a good bit after running. The carbs were supposedly rebuilt, but I cant be sure. The marina i took it too absolutely robbed me, had a $1600 list of stuff they "fixed". Most of which was not touched, ie new fuel line, vent hose, carb kits, and much much more. I raised hell considering they told me over the phone after they "diagnosed the problem" that it would be less than $300. One thing I feel could be the problem is flooding due to a stuck float? How can i test VRO to see if it is failing? What else should i be looking at?

Sorry for the long post but I would rather give all the info i can think of

The motor is actually an 87, mistyped the title.

Re: Problems with 86 Evinrude 70hp

TTT, Anybody? I am beginning to think it may be Timing advance/ throttle linkage issue. Sound like a possibility? What all goes into setting timing advance and ensuring all of the linkages are set correctly? Never messed with timing on a marine engine.

Re: Problems with 86 Evinrude 70hp

Yes, it could be a timing/linkage issue. Get yourself a factory service manual and it will go through link/sync procedure in detail.

Do your choke plates open all the way while running @ idle speed? I know my 70hp has a spring that holds the choke linkage open at WOT, but at idle, it doesn't do this. Yours may be the same way?

If your choke linkage is hanging up and restricting air flow, you could be running rich. Too rich will cause the engine to quit and experience a flooded state which will smoke more once it does start.

Re: Problems with 86 Evinrude 70hp

I don't think the 1987 models had choke plates; they should have the electric primer assy.

Take off the air silencer from the intake to expose the 3 carbs. Use your hand to move the throttle linkage to open and close the butterfly valves in all 3 carbs at once and check that they are all move in synch and are fully open at the same time. move the linkage back to idle and check that all three are fully closed at idle.

champion plugs are better for these motors. L77JC4 or QL77JC4 are the recommended plugs.

The symptoms you describe lean more towards a fuel issue than timing. Could be the fuel filter is partially clogged, an air leak in a hose or connection or clogged low speed jets.

Re: Problems with 86 Evinrude 70hp

$1600!
I bet they parked the boat where you couldnt hook it up and drive off
Maybe the shiesters put in the wrong jets in the carb

Re: Problems with 86 Evinrude 70hp

The motor does not have choke plates, it indeed has the electric primer. The butterflys are all in sync and open all the way at WOT, i do see that i may have my idle a little high because they are not completely shut when throttle is in idle position. But the amount they are open is maybe 1/32 of an inch. yet i have the idle set as low as it will go without cutting off. I know i should have asked questions first and acted later but i got screwdriver happy one day and messed with the two screws i attached pictures of. I am not really sure what they do, I thought maybe they limited the throttle movement but now that I look at it, do they have anything to do with timing? I have not messed with the screw under the flywheel that I know for sure changes the timing.

Yes $1600.00. and I could not find a single bolt they touched. They eventually dropped it to $600 to cover the "parts" and told me they didnt charge me the $1000 of labor.

Re: Problems with 86 Evinrude 70hp

That screw adjusts where the throttle stops. Doesn't affect the timing.

The engine should idle with the plates completely closed. Likely the carbs need to be taken apart and all the passages cleaned out with a thin wire or pipe cleaner. Also use spray carb cleaner to blow through each passage to ensure that they really are clear.

You can reuse all the parts and gaskets if the mechanics actually did rebuild them when they said they did.

1600 is more than that motor is worth! I would never set foot in that shop again if I were you.

Re: Problems with 86 Evinrude 70hp

duplicate..

Re: Problems with 86 Evinrude 70hp

I will never return! I had never needed professional marine engine work before and they are the only Evinrude dealer in my area so it seemed like the right thing to do. I will remove carbs tonight and see what they look like. Before I do, Are there any jet screws that will come out of adjustment when i do this? or is it as simple as take them apart, clean well, and put them back on?

Re: Problems with 86 Evinrude 70hp

I think it's as simple as disassemble, clean and reassemble on these carbs. The newer carbs from these motors have adjustable needle valves but I think the 87 and older models are fixed.

if anyone else knows for certain please chime in. It's safe to take them apart first and take a look.

Re: Problems with 86 Evinrude 70hp

If you have a manual then do a lync and sync as per manual, the butterflies should all be closed at idle and open to 90 deg at WOT. If the lync and sync doesn't help then I'd go with trensetter and do a complete overhaul of the carbs.

Re: Problems with 86 Evinrude 70hp

I just removed and disassembled carb one, expecting alot of crud. But to my surprise it is spotless. Gaskets look to be new. all jets and orifices are clean as a whistle. Blew them all out with carb cleaner anyways but there wasnt really anything to blow out. Im guessing the marina did overhaul the carbs. Judging by the first carb, should i even go through the hassle of removing the other 2?

Re: Problems with 86 Evinrude 70hp

Sportcraft, as a fellow Lake Norman resident, what marina are we talking about? That's a crazy bill.

Re: Problems with 86 Evinrude 70hp

Denver Marine. I had done business with them a few years back and they seemed ok. They sold me a used control box for a suzuki 115 for $40 with all cables. But I will not be a returning victim after the last visit. And to top it all off, i dropped my boat off in may, they told me it would be 2 weeks as they were 9 days out. I went and got my boat back in late july. And it still wasnt running. They told me they had lake tested it and it ran great for them, yet when i picked the boat up the empty coke can that i had accidentaly left on the tongue of the trailor while unhooking from my truck, was still there

Re: Problems with 86 Evinrude 70hp

Sorry to hear that. Will definately avoid them for sure.

Re: Problems with 86 Evinrude 70hp

All 3 carbs have been removed, all were spotless, blew them all out really good anyways. I honeslty do not believe they were an issue. Hear me out and let me know if this sounds reasonable, The bottom screw in the picture above was screwed way in, so far it did not alow the timing advance arm to return at idle, so if the timing was advanced at idle, was i having to run the idle higher in order to run? in which case the throttle was dumping too much gas at tolling speed, thus flooding the motor? At WOT it ran great, but if my calculations are correct, im using around 14 gallons an hour(seems like alot to me). Could it be dumping too much fuel for the rpms that the motors timing system thinks its turning? This is all pretty much a guess, but with my lacking marine engine knowledge it sounds pretty good to me. Could all of this be becasue i messed with all the throttle adjusments and just have them all out of whack?

Re: Problems with 86 Evinrude 70hp

I think I hear ya.
Maybe your butterflys a opening too advanced
I suppose you checked the slow speed orifice too.

Re: Problems with 86 Evinrude 70hp

Id the slow speed the one on top that has small holes in the top above the butterfly? i blew some carb cleaner through every opening i could find. I reassemble and found a link/ sync basic intructions online. Did everything, found out that (im an idiot) but i was not using the correct idle adjustment. I was adjusting idle using the lock nut and thumb nut on the throttle linkage. I set it back to 4 31/32 and got the mark lined back up. as expected my throttle was opening before the idle advance was moving. thus the motor was loading up with fuel and flooding. taking it now to water test.

Re: Problems with 86 Evinrude 70hp

Yep top centre front straight above main opening. You may want to check thats not blocked
Report test results please

Re: Problems with 86 Evinrude 70hp

I struggled with my 89 trying to get it to idle, seemed that there was more fuel spitting out of the carbs than being burnt, finally bought a set of carbs off a 91 with adjustable low speed jets and it runs and idles like a dream.