1971 Evinrude 85hp Starting/Throttle Issues

[evanlinz]

Alright guys, here's the situation:

I just purchased a 1974 Glastron 15ft with a 1971 Evinrude 85hp outboard and took her out for the first time a couple of days ago. Upon launch, it started right up, and with 6 people on board cruised around 30mph for maybe 15 minutes before it started "bogging" down. It picked back up in speed after a few minutes and then we came to a stop in a cove and floated for maybe another 15 minutes. When I tried to crank it back up, I got no fire. I continued to prime, choke and crank (in a revolving fashion) until the battery itself went dead without ever starting back up. We were lucky enough to be close to the dock and got a short tow in...

My immediate assumptions were:

A) The battery had insignificant voltage to provide spark.
B) The gas that came with the boat and that I was running was either a bad mix or had been sitting long enough to become varnish and quickly caused immediate clogging or fouling of the plugs.

So, yesterday, I recharged the battery (800cca) to full capacity, switched lines to a brand new 50:1 mixed tank and it once again fired upon first crank. Once I set out on the water, though it wouldn't run above 5mph or so and quickly died, leaving us floating in yet another cove. Luckily, I brought the trolling prop with me and we putted back to the dock.

I busted out the tools at this point, pulled the plugs, and found that they were NGK "surface discharge" plugs and, without a gap, made it somewhat difficult to tell whether they were acceptable. They did have a light black covering on them, though, so I suspect this to be the issue.

My plans now: Replace the plugs, clear the lines, and try again.

My question is: Am I a complete moron to suspect this to be such an easily fixable problem or is it likely to run much deeper? Should I even waste money on plugs at this point or should I perform further inspection? Any suggestions would be great and YES, I am a noob to outboards so feel free to put me in my place.

[63Sport16]

Since you admit to being a novice the guys here will try and lead you gently in the right direction. My first question is:
1. Model number?
2. Do you know any maintenance history of this motor?
3. Have you checked the spark using a spark jump tester of 7/16"?
4. Did you check by hand to see if the motor was HOT to the touch?
These are just a few questions to start your inspection of your troubles.

[Pirate_Seahorse]

Congratulations on your purchase, even though you're having a few problems. Seeing that you ran it around 30mph for about 15 minutes with a load of 6 people, I would think it's not anything too serious. My first question is, did the battery seem weak when you first tried to restart it after died? If so, the charging rectifier (and possibly the engine wiring harness, due to the engine's age) could be suspect (meaning: the battery just got weak enough it couldn't charge the coil enough for the spark plugs to fire. I think first I would try a set of plugs, and make sure the charging system is working. In case you're not familiar, you can get a voltmeter and check across the terminals of the battery with the engine slightly above idle and it should read greater than battery voltage (about 12.5V or more). I have a depth-finder and it has a voltmeter built-in and mine regularly reads 13-13.5 volts or so with a fully charged battery. My next question is, did the boat sit for "a couple years" before you bought it? If so, a carburetor kit might be a possibilty. My last question is, was the tell-tale spitting water? My boat only spits alittle out cruising around with a light load, but if you "shoot the coals to it", it immediately starts spraying water, or drop back to an idle after cruising, it'll spray out for a few seconds before becoming a light mist. Lastly, the prime bulb should stay fairly full while the engine is running, if it's not, your fuel pump isn't pumping well, or your lines/tank are clogged or allowing air in. Just a few things that I would check if I were in your shoes. If you plan to do any repair work or even regular maintenance on it yourself, I recommend a "Clymer" or "Seloc" brand repair manual. Lots of good info in them and helps to save alot of $$ instead of taking it to a repair shop that might not have any idea how to work on something "that old". Goodluck and keep us up date, so we can help keep your vintage boat on plane!

[IslandManMitch]

Clean your carburetors.

[evanlinz]

Since you admit to being a novice the guys here will try and lead you gently in the right direction. My first question is:
1. Model number?
2. Do you know any maintenance history of this motor?
3. Have you checked the spark using a spark jump tester of 7/16"?
4. Did you check by hand to see if the motor was HOT to the touch?
These are just a few questions to start your inspection of your troubles.

1) Funny story, I actually waited to reply so that I could get the model numbers off of the title, and it doesn't have either the boat or the motor's listed. It doesn't say anywhere on the motor itself either. It is, for sure, the "Starflite" model, though, if that helps.

2) I have no maintenance history whatsoever and the previous owner only had the boat for around a year according to the title.

3) I have not used a spark tester, I was waiting to get it back to the shop, if it became necessary, where the true arsenal of tools are.

4) The motor was warm to the touch around the flywheel, but this was after sitting for those 15 minutes.

[evanlinz]

Congratulations on your purchase, even though you're having a few problems. Seeing that you ran it around 30mph for about 15 minutes with a load of 6 people, I would think it's not anything too serious. My first question is, did the battery seem weak when you first tried to restart it after died? If so, the charging rectifier (and possibly the engine wiring harness, due to the engine's age) could be suspect (meaning: the battery just got weak enough it couldn't charge the coil enough for the spark plugs to fire. I think first I would try a set of plugs, and make sure the charging system is working. In case you're not familiar, you can get a voltmeter and check across the terminals of the battery with the engine slightly above idle and it should read greater than battery voltage (about 12.5V or more). I have a depth-finder and it has a voltmeter built-in and mine regularly reads 13-13.5 volts or so with a fully charged battery. My next question is, did the boat sit for "a couple years" before you bought it? If so, a carburetor kit might be a possibilty. My last question is, was the tell-tale spitting water? My boat only spits alittle out cruising around with a light load, but if you "shoot the coals to it", it immediately starts spraying water, or drop back to an idle after cruising, it'll spray out for a few seconds before becoming a light mist. Lastly, the prime bulb should stay fairly full while the engine is running, if it's not, your fuel pump isn't pumping well, or your lines/tank are clogged or allowing air in. Just a few things that I would check if I were in your shoes. If you plan to do any repair work or even regular maintenance on it yourself, I recommend a "Clymer" or "Seloc" brand repair manual. Lots of good info in them and helps to save alot of $$ instead of taking it to a repair shop that might not have any idea how to work on something "that old". Goodluck and keep us up date, so we can help keep your vintage boat on plane!

I appreciate the insight, and I agree that a manual is gonna save me a lot of guessing. The battery seemed to have plenty of power and I'm pretty sure the prolonged cranking without fire is what wore it down, but I will use a voltmeter the verify. Being that the previous owner had only been in possession of the boat for a year, it was either getting use on the water or just being passed around... he claimed to have had it out not long ago. I actually paid no attention to the water spray, so will check that if I'm able to get it out again. The prime bulb felt partially full when trying to restart and the lines actually look to be nearly new, so I think it's getting the fuel AT LEAST to the carburetor. I'm starting to think that the problem lies within just that. I gave the carb a makeshift spray cleaning before the second launching attempt but am not above now giving it a full rebuild...