Warm starting problem

[upnorth]

I have an "87" 70 horse Evinrude that is pretty much driving me insane(short trip) .

The dang thing starts fine when it is cold/sat overnight or if I run it for a while then start it up again within 20 to 30 minutes. But if I let is sit for more than that it is almost impossible to restart. If I crank on it for about 1 or 2 minutes or more 4 or 5 times it will finally go, but this just ain't right. And I am worried about burning out the starter.

I have replaced most everything in the last couple of years because of other failures, and this has always been somewhat of a problem and it is getting worse. I have replaced the fuel pump, the stator and the main power unit. The plugs are new and the gas is only 2 weeks old.

My battery seems to crank it OK but, and according to the diagnostics on my graph it is putting out 12.2 volts it is about 5 years old.

I am running out of things to try. I am running sea foam through it now, but I really don't hold much hope that will solve much.

Anyone got any ideas or experience with this kinda problem??

[trapperdirk]

Sounds like the coils are going to me .

TD

[united jigsticker]

It really sounds to me like a problem related to the amount of choking required to start the engine during luke warm periods.

Can you describe to us what your choking procedure along with cranking times and throttle position is when you attempt a restart after a 35-45 minute absence of operation please?

Some engines can be really fussy when they are in the window of needing some choke to fire off when they are luke warm.

I've had engines where you were best hitting the starter, letting it start and stall, then choking full and cranking, and it might even start and stall then (flood itself out), then you had to crank while holding WOT in order to get it to go.

In other cases, some alteration in order of the above procedure was nescessary to fire the luker up.

Thanks.

[upnorth]

I start out by leaving the throttle or fast idle adjuster alone, I found that anytime I play with that lever before turning over on a lukewarm motor I was in trouble. Turn the key and hope it starts. If it fails to start I push in the key(that controls the electric primer there is no real choke on this motor) while it is turning over. In reality that used to work 90% of the time, but has gone downhill since then.

[Valv]

Agree with U.J.

Choking when cold can be the issue

Another thing you might want to try is compression test, just go to any auto store and buy a cheap (screw on) gauge, they cost $ 25.00 and it's one of the best investiments you can do.

But beware of the results, if you have low compression or uneven compression between cylinders....you are not going to like it. Your style motor was very popular and almost same from early '70s to mid '90s, you have a VRO (oil injected) model and these first years weren't famous for quality of oil pumps.

[upnorth]

Why the coils? Not trying to be a weiny, but wondering why you think they may be failing?

[Macgyver55]

When it starts, do you need to choke it again, or does opening the throttle help? If you need to open the throttle it could be that the carbs are starting to leak some. This can allow gas to slowly seep into the cylinders while the engine is shut off causing a flooded condition. That could explain why it starts ok if you restart it soon or completely let it cool. A lot of cranking will eventually clear the excess gas allowing it to start. Bad coils could be suspect too, but if it does start after cranking a while the coils are working. Usually they won't fire again until they are all cooled off.

The most likely is a compression problem. I'd start there by checking that first.

[Valv]

Ok, sound like correct procedure. Check the 2 small fuel lines that go from primer to carbs, if you have a small air leak (fuel leak) you are not priming at all.

You should be able to keep motor running just by priming it.

[upnorth]

Valv, I replace the Fuel pump/VRO pump a few years back with the "new and improved" version. That did't really make any difference either.

If there was a compression issue, wouldn't I see it in performance?

[upnorth]

It seems to prime OK when it is cold. Would there be a difference when it is warm? It doesn't want to fire at all when it is giving me fits, so keeping it running with the primer doesn't seem feasible?

How would I be able to tell if the carbs are leaking?

[Valv]

Sorry I had to go out for a while.

Keep it running with choke I meant once it starts, you don't have to use throttle to run it, you can give it a little prime, and keep it running smooth.

There is no external leak on carbs, if the floats are too low it will flood motor, but it's not visible.

Performance with low compression can be not very different especially if just 1 cylinder is bad, but not too bad. You will get used to its own performance, that's why a test is nice to have, it will help pinpointing the problems.

Coils can create problems too, they can spark when you check the plugs, but when they are instelled and under pressure spark little or nothing at all.

I wish you were closer, I'll be glad to help you out.

[united jigsticker]

Maybe the electric choke isn't functioning properly when warm.

Just to make sure, once the engine is warmed, push in your key to activate your primer. The engine should stutter out and stall fairly quickly at idle if it is working properly when the engine is fully warmed.

IF it were the coils as one suggested, the engine most likely wouldn't restart within that 30 minute time slot as they would be warm, and most likely to malfunction at that point.

I am highly doubtful that this is the problem.

Fuel delivery in some respect is your starting culprit.

[upnorth]

Hey guys thanks for the help so far. I am going to have get my hands on a compression tester. I have an old hold it in and crank model, but I have my doubts about how well it will work.

I will post the results when I can get them. Once again thanks for helping

[Macgyver55]

A compression test will tell you a lot. If you have good compression, I'd go after a carburetor problem next.

[upnorth]

OK here are the results from the compression test. Not sure what it should be, but I think I am in the ball park of good.

From top to bottom:

1. 120

2. 120

3. 115

That is pretty close to where it should be ain't it?

[Macgyver55]

If your comp. gauge is accurate then you are in good shape compression-wise. 120 is plenty and the fact that they are all within 5% of each other is very good. At this point I'd be looking at carb rebuilds or at the very least putting in new floats and needles. My guess is that will take care of the problem.

[united jigsticker]

Would or would not the float problem create idling issues as well???? example, too rich, then too lean..etc etc etc...

[ChuckN]

I'm with UJ on this. I've had the same problems with a '89 60 Johnson and after lots of trial and error, (and getting stranded more than once) it was the electric choke.

There should be a manual override under the hood, near the carbs. It's a red lever, and try turning it when the motor acts up and see if that helps.

[Valv]

Actually Chuck made us realize we forgot the basics...do you hear the choke/primer clicking ? It should be clearly heared without hood.

[upnorth]

I can hear it click when it is cold. I will have to get it out and check to see if it clicks when it is warm. The manaul overide on the choke/primer used to work, but the last few times out even that didn't do it. Could that thing be totally failing?

[Valv]

I bet that could be the problem, Chuck is our hero here.....

[Macgyver55]

Quote:

---

Would or would not the float problem create idling issues as well???? example, too rich, then too lean..etc etc etc...

---

Not necessarily. If the needle and seats are only bleeding a small amount of fuel it would not show up much when running. 2 strokes tend to be more forgiving to excess fuel than to not enough. Over some time the residual pressure in the fuel line between the fuel pump and the carb can seep fuel until the pressure is gone.

The choke problem certainly is a possibility, and its easy (and free)to check, so do that for sure. If its not that, I'm still thinking a fuel bleed off after shut down is the culprit. If it is indeed flooded, an easy test is opening the throttle with the override when cranking. This should help clear it quicker if thats the problem.

Anyway,its tough to diagnose without actually hearing and seeing the problem as it occurs. I just thiought I'd throw this out as a possibility. Let us know what you find with these next tests.

[united jigsticker]

So here's what I would do if I suspected the carbs of leaking and flooding my engine out.

Crank it for 5-7 seconds without any choke, then pull the plugs.

Are they wet?

If they are dry, you don't have a flooding problem.

[upnorth]

Just an FYI to everyone that had some input on this earlier. I rebuilt the carbs and have had it it out 3 times and runs great, no warm starting problem. All three had some varish build (2 had very little), but the bottom one was just slimy. Actually pick up a 150 RPM @ WOT too.

Thanks for the help and suggestions